Moxostoma robustum - Robust Redhorse Conservation Committee

Transcription

Status and Assessment of Robust Redhorse (Moxostoma robustum) in the Broad River System, Georgia. Robust Redhorse captured at a spawning shoal in the Broad River, 2007. Carrie A. Straight and Byron J. Freeman Odum School of Ecology, Georgia Museum of Natural History University of Georgia Athens, GA 30602 Final Report Prepared for the Georgia Department of Natural Resources (State Wildlife Grant No. T-‐36) April 2013
Broad River Robust Redhorse reintroduction status
Table of Contents TABLE OF TABLES ......................................................................................................................... III TABLE OF FIGURES ........................................................................................................................ V TABLE OF APPENDICES ............................................................................................................... VIII EXECUTIVE SUMMARY ................................................................................................................. IX ACKNOWLEDGEMENTS ................................................................................................................. X INTRODUCTION .............................................................................................................................. 1 Stocking Chronology ................................................................................................................................... 4 MOVEMENTS ................................................................................................................................. 7 Surgery ....................................................................................................................................................... 8 Receiver Stations / Tracking Methods ...................................................................................................... 11 Movement Results ............................................................................................................................... 13 Captured Individuals ................................................................................................................................. 13 Movements of captured Robust Redhorse .............................................................................................. 14 Time of Day ............................................................................................................................................... 24 Travel Distance and Speeds .................................................................................................................. 28 REPRODUCTION ........................................................................................................................... 30 Spawning Sites ..................................................................................................................................... 30 Spawning Season ................................................................................................................................. 33 Timing ....................................................................................................................................................... 33 Tagged fish arrival at spawning sites. ....................................................................................................... 38 Spawning Microhabitat ........................................................................................................................ 39 Depth / Velocity. ....................................................................................................................................... 39 Substrate. ................................................................................................................................................. 42 Anecdotal Information / Behavior ............................................................................................................ 44 Habitat Partitioning .................................................................................................................................. 45 RECRUITMENT ............................................................................................................................. 45 Juvenile Sampling ................................................................................................................................ 45 Methods ................................................................................................................................................... 45 Juvenile Sampling Summary ................................................................................................................. 51 i
POPULATION ................................................................................................................................ 53 Recaptured Robust Redhorse ............................................................................................................... 53 Basin and Rearing Comparisons ............................................................................................................... 55 Differences in Systems ............................................................................................................................. 56 Known Age Fish .................................................................................................................................... 62 Adult spawning population size ........................................................................................................... 65 MANAGEMENT IMPLICATIONS ..................................................................................................... 66 River / Habitat Conditions .................................................................................................................... 67 Recruitment ......................................................................................................................................... 68 Molecular Markers ................................................................................................................................... 69 Future Work in the Broad ..................................................................................................................... 70 Recruitment Sampling .............................................................................................................................. 70 LITERATURE CITED ....................................................................................................................... 71 APPENDICES ................................................................................................................................. 75 Appendix 1 ........................................................................................................................................... 75 Appendix 2 ........................................................................................................................................... 76 Appendix 3 ........................................................................................................................................... 89 Summary of 2009 sampling information .................................................................................................. 89 Summary of 2011 sampling information .................................................................................................. 93 Appendix 4 ........................................................................................................................................... 98 ii
Table of Tables Table 1. Number of Robust Redhorse (Moxostoma robustum) stocked within the Broad River system from 1995-‐1998. ............................................................................................................... 5 Table 2. Estimated possible generations of reproductive-‐aged Robust Redhorse (Moxostoma robustum) in the Broad River system. Estimates assume a reproductive maturation at five years. ............................................................................................................................................. 7 Table 3. Distance of each receiver location (km) from the known spawning sites and distances between spawning sites within the Broad River Watershed and Clark’s Hill Reservoir, Georgia.
.................................................................................................................................................... 13 Table 4. Twenty Robust Redhorse (five female and fifteen males) captured and implanted with sonic transmitters. The largest and smallest individual in bold. The last column is the estimated month and year the transmitter should discontinue working using an estimated 650-‐
day tag life. .................................................................................................................................. 14 Table 5. Summary of spawning and wintering locations for tagged fish in the Broad River system and Clark’s Hill Reservoir. ........................................................................................................... 17 Table 6. Average, range (minimum -‐ maximum) and standard deviation of travel speeds (km/hr) and distances between the most upstream and downstream detections for transmittered Robust Redhorse. Travel speeds were calculated between two known localities with detections less than 30 days apart. ..................................................................................................................... 29 Table 7. Spawning site use by year by Robust Redhorse in the Broad River system from 2007 until 2012. ........................................................................................................................................... 31 Table 8. Dates of known or suspected spawning of Robust Redhorse in various basins where it occurs. ......................................................................................................................................... 34 Table 9. Average temperature (degrees C) with sample size, range, and standard error (N; range; SE) for Spotted Suckers, Notchlip Suckers, Robust Redhorse, and Northern Hogsuckers in the Broad River system from 2007-‐2012. ......................................................................................... 39 Table 10. Depths (m) and water velocities (Bottom and 60%) at spawning sites used by Spotted Suckers, Notchlip Redhorse, Robust Redhorse and River Redhorse from 2008-‐2012 (excluding 2009 when no measurements were taken). River redhorse measurements are only from 2012.
.................................................................................................................................................... 40 Table 11. Depths (m) and water velocities (bottom and 60%) at resting areas for females within spawning sites used by Spotted Suckers and Robust Redhorse from 2008-‐2012 (excluding 2009 when no measurements were taken). ........................................................................................ 41 Table 12. Juvenile sampling sites sampled in 2009. Last column represents young-‐of-‐year (YOY) Jumprocks (Moxostoma sp. and Moxostoma rupiscartes), Spotted Suckers (Minytrema melanops), and Notchlip Redhorse (Moxostoma collapsum) only. ............................................ 46 Table 13. Juvenile sampling sites chosen for 2011. Last column represents young-‐of-‐year (YOY) Jumprocks (Moxostoma sp. and Moxostoma rupiscartes), Spotted Suckers (Minytrema melanops), and Notchlip Redhorse (Moxostoma collapsum) only. Numbers represent captures in the Day sample / Night sample. .............................................................................................. 48 iii
Table 14. Example of juvenile sampling procedures dependent of the conditions at a specific patch.
.................................................................................................................................................... 50 Table 15. The number of Robust Redhorse within each Phase (Age) group stocked within the Broad River system. Years and totals within each Age group are shown in parentheses. ................... 53 Table 16. Number of Robust Redhorse stocked by year class and known numbers of each year class captured. ..................................................................................................................................... 54 Table 17. Mean and standard deviation of A. total length (mm) and B. weight (g) by river system for Robust Redhorse captured. ........................................................................................................ 57 Table 18. Mean and standard deviation of A. total length (mm) and B. weight (g) by rearing group (Broad River, other Hatchery-‐reared, or Wild) for Robust Redhorse captured. ......................... 59 Table 19. Mean probability of each Robust Redhorse captured during this study of being less than 12 years old, based on a logistic regression of 84 known age individuals. Known age reported from location of coded wire tag detected. NA indicates an absence of coded wire tag. .......... 65 Table 20. Maximum number of adult Robust Redhorse (Moxostoma robustum) counted at each spawning site and the peak date of spawning for 2010, 2011, and 2012. .................................. 66 iv
Table of Figures Figure 1. Historical range of Robust Redhorse (Moxostoma robustum) from the Pee Dee River basin in North Carolina and South Carolina south to the Altamaha River basin (Ocmulgee an Oconee Rivers) in Georgia. The type locality in the Yadkin River (Pee Dee River system) is denoted with a red diamond. .............................................................................................................................. 2 Figure 2. Map of the stocking localities (red circles with S’s) of Robust Redhorse within the Broad River system, Georgia, from 1995-‐1998. Also included are spawning localities (yellow circles with fish icons). ............................................................................................................................. 5 Figure 3. Boat electrofishing for suckers downstream of Anthony Shoals (Clark’s Hill Reservoir) and upstream of the surgery station. .................................................................................................. 8 Figure 4. Recovery net (background), holding and recovery tanks (middle), and anesthetization tank (foreground) at the surgery station along the Broad River, downstream of Anthony Shoals. ..... 9 Figure 5. Individual receiving sutures by surgeon, washing of gills, and heart-‐rate monitoring during the final steps of surgery. ........................................................................................................... 10 Figure 6. Example of a buoy (S138) used for a passive receiver within Clark’s Hill Reservoir and receiver hanging from pole that is chained from the buoy (inset). ............................................ 11 Figure 7. Map of the receiver locations (red squares) within the river and Clark’s Hill Reservoir to track transmittered fish movement. The locations marked with white circles denote the two locations with permanent receiver stations. .............................................................................. 12 Figure 8. Map of main receiver stations (buoy locations) used for tracking Robust Redhorse within Clark's Hill Reservoir. ................................................................................................................... 16 Figure 9. Movements of the six Robust Redhorse captured in 2010. River kilometer 0 was arbitrarily placed at Anthony Shoals with positive numbers upstream into the river and negative numbers indicating movements into the reservoir. Solid lines represent males and dashed lines represent females. The dashed gray line at 71 river km represents the lowest known spawning location within the system. ......................................................................................................... 20 Figure 10. Movements of the twelve Robust Redhorse captured in 2011. River kilometer 0 was arbitrarily placed at Anthony Shoals with positive numbers upstream into the river and negative numbers indicating movements into the reservoir. Solid lines represent males and dashed lines represent females. The dashed gray line at 71 river km represents the lowest known spawning location within the system. ............................................................................. 22 Figure 11. Pool elevation (FT-‐MSL) in Thurmond Reservoir (Clark’s Hill) from January 2010 to January 2011. .............................................................................................................................. 22 Figure 12. Movements of four individual Robust Redhorse within Clark’s Hill Reservoir. Distances up and down represent relative distances upstream and downstream of the Broad River mouth within the main portion of the reservoir. ................................................................................... 23 Figure 13. Percentage of movements of female and male Robust Redhorse by time of day (partitioned by two hours). ......................................................................................................... 25 Figure 14. Percentage of A. male and B. female movements within the reservoir, river, and in the vicinity of the spawning shoal by time of day (partitioned by two hours). ................................. 26 v
Figure 15. Percentage of female and male Robust Redhorse movements within the reservoir (winter) by time of day (partitioned by two hours). ................................................................... 27 Figure 16. Percentage of female and male Robust Redhorse movements within the river (migration) by time of day (partitioned by two hours). ................................................................................. 27 Figure 17. Percentage of female and male Robust Redhorse movements in the vicinity of the spawning shoal by time of day (partitioned by two hours). ....................................................... 28 Figure 18. Spawning localities (yellow indicators) and their abbreviated names (used within the text) of Robust Redhorse in the Broad River watershed used from 2007 to 2012. .................... 30 Figure 19. Typical spawning lens (three lenses visible, noted with red arrows) created through the act of repeated spawning by Robust Redhorse within the Broad River system. ........................ 32 Figure 20. Timing of spawning season for Moxostoma robustum, M. sp. “brassy”, M. collapsum, Minytrema melanops, and Hypentelium nigricans in the Broad River, Georgia. ........................ 37 Figure 21. Conceptual diagram of the spawning shoal at Wagoners. Top and bottom gray lines indicate river right and river left banks, respectively. Brown areas indicate exposed gravel islands. Gray chevron-‐shapes in the upstream indicate bedrock ledges and gray, mottled shapes indicate areas of submerged spawning gravel consistent with the size used by Robust Redhorse. Areas of purple indicate spawning use areas by Spotted Suckers. Notchlip Redhorse used the area with orange. Robust Redhorse used areas in red. ............................................... 37 Figure 22. Spawning period for Robust Redhorse (Moxostoma robustum) at four localities in the Broad River system from 2010 to 2012. ..................................................................................... 38 Figure 23. Mean monthly discharge (cfs) from 2002 to 2012 for USGS gage 02191300, Broad River at Carlton, Georgia. Data for Oct-‐Dec 2011 and all of 2012 were averaged from provisional data. Median flows were taken from data spanning 1899-‐1913 and 1997-‐2011. ............................... 41 Figure 24. Substrate fractions (mm) used at spawning sites for Spotted Suckers, Notchlip Redhorse, and Robust Redhorse in 2010, 2011, and 2012. Proportions represent the percent of the total weight for each year. Sample size represents the total number of spawning patches, with four samples taken within each patch. ............................................................................................... 43 Figure 25. Conceptual diagram of a sampling site with heterogeneous habitat and sampling patches (shown as red squares. ............................................................................................................... 50 Figure 26. Locations of spawning sites for Robust Redhorse (Moxostoma robustum; yellow indicators), and juvenile sampling sites in 2009 within the Broad River, Georgia watershed. Red circles indicate locations where young-‐of-‐year suckers were captured and white squares indicate no young-‐of year suckers captured. .............................................................................. 51 Figure 27. Locations of spawning sites for Robust Redhorse (Moxostoma robustum; yellow indicators) and juvenile sampling locations in 2011 within the Broad River, Georgia watershed. Red circles indicate locations where young-‐of-‐year suckers were captured and white squares indicate no young-‐of year suckers captured. .............................................................................. 52 Figure 28. Total length categories (mm) for Robust Redhorse captured within the different river systems within its range. Top includes the Oconee River fish captured; bottom excludes Oconee River fish to show details between the other river systems. Broad River, Ocmulgee, and Ogeechee consist all or primarily of stocked individuals. .................................................... 56 vi
Figure 29. Weight categories (g) for Robust Redhorse captured within the different river systems within its range. Top includes the Oconee River fish captured; bottom excludes Oconee River fish to show details between the other river systems. Broad River, Ocmulgee, and Ogeechee consist all or primarily of stocked individuals. ............................................................................ 58 Figure 30. Total length categories (mm) of Robust Redhorse from the Broad River, other hatchery-‐
reared (Ogeechee, Ocmulgee) and wild-‐reared individuals. ...................................................... 59 Figure 31. Weight categories (g) of Robust Redhorse from the Broad River, other hatchery-‐reared fish (Ogeechee, Ocmulgee) and wild-‐reared individuals. ........................................................... 60 Figure 32. Weight-‐total length relationship of Broad River Robust Redhorse (red squares, black line) used in this study compared to other Hatchery-‐reared Robust Redhorse (blue diamonds, blue line). ............................................................................................................................................ 61 Figure 33. Weight-‐total length relationship of Broad River Robust Redhorse (red squares, black line) used in this study compared to Wild-‐reared Robust Redhorse (green triangles, green line). .... 61 Figure 34. Relationship of weight (g; red squares) and total length (mm; blue diamonds) for known age fish. Age 1 fish were measured upon removal from hatchery sources. The two points marked with asterisks were from four fish that spent three to six years at the hatchery prior to stocking. ...................................................................................................................................... 62 Figure 35. Ratio of total length to weight, by known age of coded wire tagged Robust Redhorse. .. 63 Figure 36. Mean probability and credible interval that an individual Robust Redhorse from 450 – 700 mm total length is less than 12 years old based on a logistic regression using 84 known age individuals. .................................................................................................................................. 64 vii
Table of Appendices Appendix 1. Robust Redhorse stocking sites, dates, and total individuals released into the Broad River Watershed from 1995-‐1998.. ............................................................................................ 75 Appendix 2. All of the known captures of Robust Redhorse within the Broad River system since their initial stocking in 1995. .. ............................................................................................................ 76 Appendix 3. Summary of juvenile Robust Redhorse sampling information for 2009 and 2011 in the Broad River system, Georgia. ...................................................................................................... 89 Appendix 4. The probability (1-‐odds) that an individual fish with the given total length (mm) and weight (1000-‐4000 g) is less than 12 years old presented as means (credible interval). ........... 98 viii
Executive Summary In an effort to conserve Robust Redhorse, over 33,000 Robust Redhorse fingerlings and juveniles were stocked into the Broad River system of Georgia from 1995 to 1998 to establish an additional population within the historical range of the species. This study attempted to assess the condition of the Robust Redhorse population in the system using sonic telemetry and surveys within the system. During this study we captured 20 Robust Redhorse (5 females; 15 males) that were implanted with sonic transmitters. Many of the tagged fish wintered within Clark’s Hill Reservoir and migrated upstream to spawn in the upper areas of the system (over 70 river km). Some individuals showed some spawning and wintering-‐site fidelity. Although in the summer-‐fall-‐winter of 2011-‐2012, low flows may have altered some movements and wintering localities. We located six distinct spawning sites within the upper Broad River system (North Fork, Hudson, Wagoners, ds Wagoners, Powerline, and us Highway 281). Use of these sites appeared variable, with some sites not being used every year. The Hudson and Wagoners site was used each year we could make visual observations. The spawning season occurred between 26 April and 23 May and lasted from 12 to 21 days in length, typically peaking near the middle of each spawning season each year. Spawning temperatures ranged from 16 – 24.6 °C. Spawning depths ranged from 0.29-‐1.04 m and velocities ranged from 0.24-‐1.4 m/s at 60% of water depth. We counted a total of 86-‐107 fish spawning each year. Our tagged fish first arrived at known spawning sites approximately 20 days before the spawning season started. To assess recruitment, we sampled for juvenile Robust Redhorse. We sampled 21 sites in 2009 and 15 sites in 2011. We did not catch any Robust Redhorse during this sampling. In 2009 we captured young-‐of-‐year (YOY) Spotted Suckers (Minytrema melanops), jumprocks (Moxostoma rupiscartes or Moxostoma sp. (Brassy Jumprocks)), and Notchlip Redhorse (Moxostoma collapsum) at 12 of the 21 sites. In 2011, we focused on the region of the system where most of the YOY suckers were captured in 2009. We also added night sampling at several of the sites to provide variation in capture. We collected YOY suckers at 14 of the 15 sites. ix
Acknowledgements We would like to thank Dr. Stephen Divers and Dr. Jörg Mayer, both Small Animal Medicine & Surgery faculty members at the University of Georgia’s College of Veterinary Medicine and their numerous students and residents for their invaluable advice and for performing all of the surgical procedures for the project. We would also like to thank all of the “Freeman Lab” for their help in logistics and field work. We thank Brett Albanese and Jimmy Evans for guidance and comments on the paper. This work could not have been completed without the permission of private and public landowners to access the river at the spawning localities. Funding for this study was provided by a State Wildlife Grant through the Georgia Department of Natural Resources and the United States Fish and Wildlife Service. Work for this project was done under and in compliance of the University of Georgia’s Animal Care and Use Committee (IACUC) permit AUP # A2008-‐10180-‐0. x
Introduction Robust Redhorse (Moxostoma robustum (Cope) are large catostomids native to southeastern Atlantic slope drainages from the Yadkin-‐Pee Dee River system in North Carolina south to the Altamaha River drainage (Oconee and Ocmulgee Rivers) in Georgia. Three existing wild populations are restricted to limited portions of the Oconee River, Georgia, Savannah River, Georgia / South Carolina, and the Pee Dee River drainage, North Carolina / South Carolina (Figure 1). Population estimates of Robust Redhorse in the Oconee River system from 2001 to 2004 was approximately 100 adult Robust Redhorse (Slaughter 2011). These estimates showed a decline from the estimates of made between 1999 to 2002 of 300-‐500 individuals. Since 2004 limited captures have prevented any population estimates. The adult Robust Redhorse population in the Pee Dee River was estimated to be less than 150 individuals from 2006 to 2008 (Ryan Heise, RRCC 2012). Adult spawning population size of the gravel bars used in the Savannah River in 2004 and 2005 was estimated to be between 82-‐85 individuals (Grabowski and Isley 2008). Unless unknown spawning localities occur elsewhere within the Savannah system, this population estimation also suggests a limited population size. Using genetic analyses, estimates of the temporary effective population size of the Robust Redhorse population is estimated to be 80-‐160 individuals in the Savannah River basin and 10-‐20 in the Pee Dee River basin (Tanya Darden, RRCC 2011). Estimates from these wild populations indicate a species in peril. Wild Robust Redhorse throughout their range persist with a large portion or all of their range in the Coastal Plain of the Pee Dee, Savannah, and Oconee Rivers. These Coastal Plain reaches of river within Georgia are characterized by broader floodplains, more erodible substrates (sand) and lower gradient than those within the Piedmont regions (Berndt et al. 1996) and flows are often influenced by production at hydropower facilities. Robust Redhorse were originally described under the scientific name Ptychostomus robustus by Cope in 1870. After this original description, ichthyologists misapplied this scientific name to the species that is now known as the Brassy Jumprock, Moxostoma sp. cf. lachneri, and called the Smallfin Redhorse. This incorrect classification persisted until the late 1990’s. Although at the time of collection the identity of the species was unknown, the next scientific collection of Robust Redhorse occurred in 1980 by biologists from the National Academy of Sciences in the Savannah River. In 1991, a collection of five suckers in the Oconee River occurred during surveys conducted for Federal Energy Regulatory Commission (FERC) re-‐licensing of Georgia Power Company's Sinclair Reservoir project. Researchers studied these individuals along with the individual collected in 1980, Page 1
another collected in the Savannah in 1982, and one caught in the Pee Dee River in 1985. Comparisons of these fish with the description revealed that these unidentified fish most appropriately fit the description of Robust Redhorse written by Cope rather than the species previously thought to be Ptychostomus robustus, now considered brassy jumprocks. The long entangled taxonomic history of this species and its effective disappearance from 1870 until the 1990’s resulted in a lack of natural history information concerning this species. Figure 1. Historical range of Robust Redhorse (Moxostoma robustum) from the Pee Dee River basin in North Carolina and South Carolina south to the Altamaha River basin (Ocmulgee an Oconee Rivers) in Georgia. The type locality in the Yadkin River (Pee Dee River system) is denoted with a red diamond. After its “rediscovery”, fisheries scientists began intensive surveys to determine the extent of the population within the Oconee River, the only population known to exist at the time. In 1991 nine individuals were captured within the Oconee River between Sinclair Dam and Dublin. Researchers continued extensive surveys in the Oconee River and captured 57 individuals in 1992 and 51 in 1993. Early sampling suggested that while the species appeared relatively abundant in the Oconee Page 2
River compared to other rivers, recruitment rates were extremely low, and because of scientists' insufficient knowledge of the species’ threats and life history needs, the U.S. Fish and Wildlife Service listed it as a Species of Special Concern (formally known as a Category 2 candidate species). In addition, the state of Georgia listed this species as Endangered. The discovery of the only known population of Robust Redhorse below a hydropower project applying for renewal of a license prompted the discussion of potential listing under the Endangered Species Act. To accommodate concerns of all parties, avoid immediate listing, and immediately begin recovery efforts, a Memorandum of Understanding (MOU) was developed involving federal, state, and private partners, including Georgia Power, US Fish and Wildlife Service, Georgia Department of Natural Resources (GDNR), South Carolina Department of Natural Resources (SCDNR), North Carolina Wildlife Resources Commission, United States Geological Survey, and other utilities and conservation groups. In 1995 this MOU formalized the creation of the Robust Redhorse Conservation Committee (RRCC). The initial purpose of the RRCC was to create a prelisting species recovery plan with the long-‐term goal of recovering the Robust Redhorse. The populations of Robust Redhorse that persist in the Pee Dee as well as the Savannah and Altamaha drainages are assumed to be dramatically reduced compared to E. D. Cope's (1870) accounts of fishery catches of the sucker. “But unfortunately, too many of the people with the improvidence characteristic of ignorance, erect traps, for the purpose of taking the fishes as they ascend the rivers in the spring to deposit their spawn. Cart loads have thus often been caught at once, so that the supply is at the present time reduced one half in many of the principal rivers of the State.” Cope (1870) Even at the time of its original description, Cope had concern of overfishing. Currently, all remaining populations persist in rivers with flows influenced by hydropower dams. The Oconee River population appears to be skewed toward older age classes and concerns remain that spawning or juvenile habitat may be limiting or other factors may be involved in recruitment limitation (RRCC 1997). Even as early as 1997, sampling efforts resulted in 42% recaptures and as few as 2% were considered immature (< 420 mm total length). The goal of the RRCC is restoration of the species. According to the RRCC goals, restoration would be deemed successful when six self-‐sustaining populations occur throughout the species’ historical range (Nichols 2003). Self-‐sustaining, as defined by the RRCC, means that “a population or all Page 3
known populations are at a level where the natural recruitment rate is equal to or greater than its mortality” (RRCC 2002). At “…a minimum, 22 years would be required to determine if a population of Robust Redhorse has sufficient recruitment from multiple year classes to maintain its numbers or be self-‐sustaining” (RRCC 2002). Other goals of the RRCC include understanding the biology of the species and understanding threats to sustainability and recovery of the species. As of summer 2012, the smallest known, wild-‐reared individual captured was 304 mm TL from the Savannah River. Since 1991 less than 2100 documented (wild and hatchery-‐reared) Robust Redhorse have been captured within its range. In the early 1990’s, the RRCC acknowledged that the Oconee River population was possibly the only significant population of Robust Redhorse remaining within its presumed historical range, the group determined that the establishment of additional populations via artificial breeding and stocking was essential for the preservation of the species and to meet the goal of six self-‐sustaining populations. The goal of the RRCC stocking program was to identify potential river systems for reintroduction of Robust Redhorse and to implement a stocking program utilizing the existing Oconee River population as the source. Stocking Chronology One of the systems chosen for reintroduction efforts was the Broad River system (Savannah River Drainage) of Georgia. The Broad River was prioritized as the best option for stocking because of the availability of good habitat (sand and gravel with interspersed shoals), relatively good water quality, the watershed was relatively undeveloped, and there were no hydropower or major water development projects within the system. At the time of stocking, there was no evidence of the existence of a wild robust redhorse population in the Broad River system. The first propagation effort began with artificial spawning projects in 1992 and 1993. The release of captively-‐propagated Robust Redhorse began with a modest effort in March 1995, followed by a larger releases in the fall of 1996, 1997, and 1998 (Table 1; see also Table 15 and Table 16). Brood fish obtained from the Oconee River were utilized to produce fingerlings for release into the Broad River system to create an additional population of Robust Redhorse. From 1995 to 1998, 33,743 fish representing 1993, 1995, 1997, and 1998-‐year classes of artificially propagated Oconee River-‐derived Robust Redhorse were released into the Broad River and its major tributaries in Franklin, Madison, and Oglethorpe Counties, Georgia (Figure 2; Table 1; Appendix 1; Page 4
Freeman et al. 2002). Before release, each stocked fish was fitted with a binary coded wire tag in different locations to facilitate aging of captively-‐reared fish recaptured after their release. Tag placement for each year class was unique: 1993 year class in the left cheek, 1995 in the right cheek, 1997 at the base of the dorsal fin, and 1998 at the base of the anal fin. Figure 2. Map of the stocking localities (red circles with S’s) of Robust Redhorse within the Broad River system, Georgia, from 1995-‐1998. Also included are spawning localities (yellow circles with fish icons). Table 1. Number of Robust Redhorse (Moxostoma robustum) stocked within the Broad River system from 1995-‐1998. Stocking Year Year Class Number of Individuals 1995 1996 1997 1998 1998 1993 1995 1997 1997 1998 545 1424 25207 3841 2726 Page 5
In 1997, two Robust Redhorse were captured in the Savannah River system downstream of Augusta. Six individual Robust Redhorse were captured during collections from October 1997 to October 1998 in the Savannah River. These collections documented the existence of a previously unknown population of Robust Redhorse within the Savannah drainage of which the Broad River was part. Personnel from the University of Georgia took tissue samples from individuals in the Savannah to compare mtDNA with individuals from the Oconee River. Analysis of the tissue samples revealed that the Robust Redhorse in the Savannah River were from a different Evolutionary Significant Unit (ESU) than those stocked in the Broad River system, which were progeny of Oconee River broodstock (Wirgin et al. 2001). This research concluded that reproductive isolation of these two riverine populations is complete and they have been isolated for some time. In 1998, stocking was halted before the planned five years of stocking was completed because of concerns of individuals stocked into the Broad River system could possibly by-‐pass Thurmond (Clark’s Hill), Stevens Creek, Augusta Canal Diversion, and the New Savannah Bluff Lock and Dams and mix with the wild population occurring downstream in the Savannah River. In past reintroduction efforts of salmonids, stocked individuals replaced indigenous populations of the same species in just a few generations (Evans and Willox 1991). This mixing could alter the genetic adaptations these populations have made to their native river systems, however the consequences of mixing the two robust redhorse ESUs in the Savannah River drainage is unknown. As of 2012, we are aware of no evidence that mixing of the stocked population in the Broad River, Georgia and the wild Savannah population has occurred. As of 2012, individuals originally stocked in the Broad River system were 14-‐19 years old (1998 to 1993 year classes) and were well within the known spawning age (minimum of five to six years) for this species (BJF, personal data). If the minimum spawning age is assumed to be five years, reproduction was successful, and young survived from the first reproductive year of each generation, the first generation of wild-‐spawned fish within the Broad River system should have entered the adult reproductive population between 2003 and 2008 and a possible second generation would enter the reproductive population between 2008 to 2013 (Table 2). Page 6
Table 2. Estimated possible generations of reproductive-‐aged Robust Redhorse (Moxostoma robustum) in the Broad River system. Estimates assume a reproductive maturation at five years. Stocking Year Class 1993 1995 1997 1998 First Estimated Reproductive Year of Stocked Individuals 1998 2000 2002 2003 1st Generation Estimated Reproductive Year 2003 2005 2007 2008 2nd Generation Estimated Reproductive Year 2008 2010 2012 2013 Since their stocking in the Broad River system, many individuals have been collected in Clark’s Hill Reservoir during yearly sampling efforts (Appendix 2; see section on Population). This report is intended to address the status of the population of Robust Redhorse in the Broad River system. Knowing the effectiveness of the stocking program, as well as reproduction and habitat use for this population, will greatly aid future recovery efforts for the species in other drainages. Movements To track Robust Redhorse within the Broad River system and Clark’s Hill Reservoir, we implanted sonic transmitters (V13T-‐1L; VEMCO Ltd, Halifax, Nova Scotia) into Robust Redhorse in the spring of 2010 and 2011. The transmitters were 13mm in diameter, 41mm length and approximately 6 grams in weight. The recommended transmitter weight is less than 2% of the body weight of the individual (Winter 1996). Each tag had an expected tag life of 650 days and transmitted the tag ID information on a random cycle of 45-‐135 seconds. Because sonic transmitters are limited to projecting pulses through water, this choice was ideal for tracking Robust Redhorse as they move through deeper waters within the reservoir. However, detection of transmitters within shallow water and the spawning shoals themselves were limited (no manual detections were made within the river or spawning shoals), presumably because water was too shallow and turbulence created interference precluding detection of fish. Using a transmitter with a shorter random cycle of pulse times (i.e. 30-‐90 seconds) might help increase detection within the river or spawning shoals. We chose to collect and tag fish before fish completed their migration upstream to the spawning shoals and hopefully, before reproductive organs are enlarged to avoid risk of nicking internal organs and added stress that may occur with tagging fish closer to the time of spawning (Jepsen et al. 2002). We chose to not tag after March to allow fish a month of recovery time prior to the start of spawning season. Page 7
Surgery All fish surgeries were conducted by advanced vet school students under direction of Dr. Stephen Divers or Dr. Jörg Mayer, both Small Animal Medicine & Surgery faculty members at the University of Georgia’s College of Veterinary Medicine. We set up a surgery station on the bank within 200 m downstream of the base of Anthony Shoals. On each collecting day, fish were collected using a boat electrofisher and held in an aerated holding tank with native river water prior to anesthesia (Figure 3). Most fish were captured within and along the edges of the main channel along river immediately downstream of the last main bedrock ledges within Anthony Shoals. The electrofishing array consisted of one or two anode rings with stainless steel cable droppers; each attached to a fiberglass pole (Wisconsin-‐type) and used pulsed DC outputs. The boat’s hull served as the cathode via a grounding connection using a Smith-‐Root™ 2.5 GPP unit. During the first collection event of each year (2010 and 2011), suckers of each species were collected and assessed for spawning condition. After initial assessment, only Robust Redhorse were netted to decrease the likelihood of missing a target species while handling a different species of fish. One to three Robust Redhorse were transferred to the surgery station at a time to minimize the length of time fish remained in holding tanks. Figure 3. Boat electrofishing for suckers downstream of Anthony Shoals (Clark’s Hill Reservoir) and upstream of the surgery station. Page 8
Each captured fish was anesthetized for surgery using buffered tricaine methanesulonate (MS-‐222 at 150 mg/L; Figure 4). Buffering agent used was sodium bicarbonate at approximately 300 mg/L to obtain a neutral pH or pH similar to the water where the fish were collected. Fish were monitored in the anesthetization tank until respiration and heart rate slowed and the individual was non-‐
reactive to withdrawal stimuli (e.g. tail or lip pinch). Before surgery, each individual was checked for the presence of an existing sonic, passive integrated transponder (PIT), or coded wire tag, weighed (g) and measured (total length and standard length (mm)). The condition of each animal was then assessed prior to surgery. If an individual had any existing condition where a surgical procedure was deemed inappropriate due to additional stress exerted on the animal, the fish was measured given a PIT tag and released (conditions could include individuals with excessive fin damage, wounding, evidence of disease, or individuals appearing grossly underweight). No individuals captured during this study had any existing conditions to preclude tagging. Any individual smaller than 200 mm TL would have been considered too small to receive a sonic tag, and would receive only a PIT tag (no fish of this size was captured during this study). Figure 4. Recovery net (background), holding and recovery tanks (middle), and anesthetization tank (foreground) at the surgery station along the Broad River, downstream of Anthony Shoals. Sonic tags and pit tags were gas sterilized prior to surgery. In the field, all surgical equipment was sterilized in 2% glutaraldehyde and rinsed in sterile water prior to each fish surgery. Before surgery begins, each individual was given an injection of an anti-‐inflammatory, Meloxicam, at a dose of 0.2 Page 9
mg/kg and an injection of a broad-‐spectrum antibiotic, Ceftazidime, at a dose of 22 mg/kg by intramuscular injection, to decrease recovery time, minimize any discomfort, speed their return to normal swimming and response behaviors, and minimize chances of infection. A four cm ventral midline skin incision was made, starting eight cm cranial (anterior) to the pelvic fins. The ventral midline was heavily muscled and bluntly dissected to gain access to the coelomic cavity. The transmitter and PIT tag were inserted prior to single layer closure using 2/0 Monocryl-‐Plus suture in a simple interrupted pattern. After surgery was completed, we collected a small tissue sample from the pelvic fin that we stored in 95% ethanol along with one to two scale samples were taken from the area above the lateral line and below the dorsal fin in addition to any scales that were removed during the surgical procedure. Heart rates were monitored during the surgical procedure to assess each fish’s condition throughout the surgery. During the surgery procedure, a student used a dilute solution of anesthetization water or plain river water to wash over the head, mouth, eyes, and gills of the individual fish (Figure 5). Figure 5. Individual receiving sutures by surgeon, washing of gills, and heart-‐rate monitoring during the final steps of surgery. After surgery, each individual was held in an aerated recovery tank with native water until they could maintain an upright position and responded to stimulus. After initial recovery each individual was moved to a flow-‐through enclosure placed in the river near the surgery locale for a minimum of 20 minutes or until each individual was responsive and swimming and other behavior is deemed normal. After all electrofishing was completed for the day, we released the transmittered fish and any recaptured individuals into the river at the surgery site. Surgery times took from seven to twelve minutes from induction to an individual being placed within the recovery tank. Page 10
Figure 6. Example of a buoy (S138) used for a passive receiver within Clark’s Hill Reservoir and receiver hanging from pole that is chained from the buoy (inset). Receiver Stations / Tracking Methods Transmittered fish were tracked using either a VR100 manual tracking receiver or VR2W stationary, submersible, passive receiver. For stationary receivers within the river, we attached receivers to a chain that was secured to a tree on the bank. Each receiver was submerged in an area near the access site with deeper than average water. Within the reservoir, stationary receivers were hung, upside down from mid-‐channel buoys or in one case a warning buoy (Figure 6). Stationary receivers were placed within the river in the spring and early summer to track individuals’ movements within the river and then were moved and placed within Clark’s Hill Reservoir during the late summer through the winter (Figure 7). We chose locations within the reservoir that were in areas with constrictions in the total width of the water to increase the likelihood of detection and in locations to help determine which part of the reservoir a transmittered fish was in at any given time. The reservoir receivers included one downstream of Anthony Shoals on the warning buoy upstream of the Highway 79 bridge, one upstream of the Broad River mouth (S138), and one downstream of the Broad River mouth (S134). Additionally, we placed a receiver near the mouth of Russell Creek (S144) and during the winter of 2011-‐2012 we placed receivers at three downstream buoys (S123, S89, S45). Page 11
Figure 7. Map of the receiver locations (red squares) within the river and Clark’s Hill Reservoir to track transmittered fish movement. The locations marked with white circles denote the two locations with permanent receiver stations. Two permanent receiver locations were selected for the duration of the study: one within the river, approximately midway between the reservoir influence and the most upstream spawning location and one near the influence of Clark’s Hill (Clark’s Hill Highway 79; Figure 7). Along with receiver stations, we also used the manual receiver to target fish within Clark’s Hill Reservoir. Within the river, we placed receivers near access points or near the spawning sites in areas with deeper water that could potentially be used as resting areas by fish as they moved within the system. We checked receivers approximately once every one or two months while fish were in the reservoir, typically from July to February. During spring migration, we checked receivers at least once a month to track fish movement from the reservoir upstream to the spawning areas. During the late spring – summer (May, June, and July), we checked the receivers once a month. For reference, distances between receiver locations and known spawning sites are in Table 3. Page 12
Table 3. Distance of each receiver location (km) from the known spawning sites and distances between spawning sites within the Broad River Watershed and Clark’s Hill Reservoir, Georgia. Receiver Locations Hudson River Hwy 29 Broad River Hwy 29 Broad River Hwy 281 Broad River Hwy 172 Broad River Hwy 77 Broad River Hwy 17 Clark's Hill (S45) Clark's Hill (S89) Clark's Hill (S123) Clark's Hill (S134) Clark's Hill (S138) Clark's Hill (S144) Clark's Hill (Hwy 79) Broad us 281 -‐8.77 -‐10.17 1.09 16.19 45.35 59.19 113.88 100.78 87.08 81.28 82.08 85.38 73.48 Broad Power line -‐5.15 -‐6.55 4.71 19.81 48.97 62.81 117.48 104.38 90.68 84.88 85.68 88.98 77.08 Spawning Locations Broad Broad ds Wagoners 5.12 5.35 2.64 2.87 13.9 14.13 29 29.23 58.16 58.39 72 72.23 126.78 126.98 113.68 113.88 99.98 100.18 94.18 94.38 94.98 95.18 98.28 98.48 86.38 86.58 North Fork 8.39 5.91 17.17 32.27 19.94 75.27 130.08 116.98 103.28 97.48 98.28 101.58 89.68 Hudson 1.1 3.58 10.96 26.06 55.22 69.06 123.78 110.68 96.98 91.18 91.98 95.28 83.38 Spawning Locations Broad us 281 0 3.62 12.81 13.04 16.08 9.87 Broad Power line 3.62 0 9.19 9.42 12.46 6.25 Broad ds 12.81 9.19 0 0.23 3.27 6.22 Broad Wagoners 13.04 9.42 0.23 0 3.04 6.45 North Fork 16.08 12.46 3.27 3.04 0 9.49 Hudson 9.87 6.25 6.22 6.45 9.49 0 *Negative numbers indicate the spawning location is downstream of the receiver location. Movement Results Captured Individuals We captured twenty Robust Redhorse in the spring of 2010 and 2011 (Table 4). We captured six individuals in the spring of 2010 (two females and four males) and 14 additional Robust Redhorse in the spring of 2011 (three females and eleven males). One individual (53964) was initially captured in 2010 and recaptured approximately one year after its initial capture and surgery for transmitter implantation. This individual was in good condition and there were no signs of surgical scar from the previous year. A few of the individuals had characteristics similar to other hatchery-‐reared fish found within the Broad River system including missing, reduced, or malformed dorsal and anal fin rays. The fish ranged in size from 439-‐555 mm standard length, 535-‐690 mm total length, and 1890-‐
4330 g in weight. Given a transmitter size of 6 g, the transmitter size was less than 1% of the body weight of each tagged individual. Page 13
Movements of captured Robust Redhorse All of the tagged fish were captured at the base of or immediately downstream of Anthony Shoals. Given this locality is within the influence of Clark’s Hill Reservoir, each fish was assumed to have spent the winter prior to their tagging within some portion of Clark’s Hill Reservoir. A summary of the wintering locations and spawning locations for each tagged individual is given in Table 5. Table 4. Twenty Robust Redhorse (five female and fifteen males) captured and implanted with sonic transmitters. The largest and smallest individual in bold. The last column is the estimated month and year the transmitter should discontinue working using an estimated 650-‐
day tag life. Estimated Transmitter Date 12/11 12/11 12/11 12/11 12/11 12/11 12/12 12/12 12/12 12/12 1/13 1/13 1/13 1/13 1/13 1/13 1/13 1/13 1/13 1/13 Year Total Length Standard Weight Date ID Sex Class* (mm) Length (mm) (g) 3/19/10 53948 male 1997 624 515 3434 3/19/10 53949 male 1997 608 501 3006 3/19/10 53961 female 1997 570 474 2490 3/19/10 53962 female 1997 563 465 2890 3/19/10 53964** male 1997 590 490 2614 3/19/10 53965 male 1997 541 452 2442 2/25/11 53953 male 1997 690 510 4330 2/25/11 53967 male 1997 662 555 4126 3/4/11 53958 male 1997 555 460 2350 3/4/11 53972 male 1997 564 470 2470 3/25/11 53951 female 1997 579 467 2800 3/25/11 53955 male CNL 544 442 1990 3/25/11 53956 male CNL 566 460 2450 3/25/11 53959 male CNL 535 439 1890 3/25/11 53963 female CNL 620 510 3340 3/25/11 53966 male 1997 566 465 2360 3/25/11 53971 male 1997 564 460 2400 3/25/11 53974 female 1997 615 495 3350 3/25/11 53975 male CNL 563 450 2740 3/25/11 53977 male 1997 610 470 3420 * Year class CNL indicates no coded wire tag was located. ** This individual was captured two times during the 2011 spring sampling. There was no evidence of surgery and appeared to be in good condition. Of the twenty-‐tagged individuals, one individual was not detected after tagging (53951). One additional tag was stationary since the day after tagging (53971) indicating a potential tag expulsion or mortality. Within the Pee Dee River ten of thirty fish expelled their tags or died within two months of receiving transmitters (Fisk 2010). However, at least three Robust Redhorse tagged prior Page 14
to the previous mentioned study had survived after expelling their radio transmitters, indicating that there is some survival of individuals expelling their transmitters. In a similar study within the Savannah River, Grabowski and Isley (2006) noted 6 of 24 transmittered fish expelled their tags or died within two weeks after their release from surgery. Of the remaining 18 individuals, we recorded over 93,500 detections with either passive receivers or using manual tracking. Two individuals, both males, were not recorded after four and six weeks of their surgeries (53975 and 53959, respectively); tracking of both individuals was limited to a partial upstream migration (but within area of the downstream-‐most two spawning locations). Two more individuals were not detected after two months. Both of these individuals (53949 and 53955) also males, were recorded at a spawning site and after the spawning season, but we have no record of these individuals after the May of their tagging year. Because tracking individuals within the spawning shoals was not possible, during the 2011 and 2012 spawning season we placed receivers downstream of the spawning sites, and in deeper holes within the spawning site. We tracked individuals to the two main spawning sites (Hudson and Wagoners) during each year. These two main sites were within 6.5 km of each other, but on different rivers (Table 4). In 2012, we located two previously unknown spawning localities, which may have accounted for the number of fish that were not tracked to the two main sites. Four individuals tracked to spawning sites showed some year-‐to-‐year spawning site fidelity (Table 5). One individual (53961) female was located at both of the main sites during the 2010 and 2011 spawning seasons. One other individual (53948) also visited both main sites, but only during the 2011 season. In both 2010 and 2011, the spawning season within the Hudson River site ended earlier than the Wagoners site, allowing fish to move to the Wagoners site and potentially participate in spawning. Wild-‐
reared Robust Redhorse within the Savannah River also showed fidelity of spawning and wintering sites (Grabowski and Isely 2006; Fisk 2010). Sicklefin Redhorse (Moxostoma sp.) also showed a high degree of spawning and wintering site fidelity (Favrot 2009). Because of limited detection of our sonic transmitters within the spawning shoals, we will address the habitat use of all spawning Robust Redhorse in the Reproduction section. Page 15
Figure 8. Map of main receiver stations (buoy locations) used for tracking Robust Redhorse within Clark's Hill Reservoir. Page 16
Table 5. Summary of spawning and wintering locations for tagged fish in the Broad River system and Clark’s Hill Reservoir. ID 53948 Sex male Tag Day 3/19/10 Total Length (mm) 624 53949 male 3/19/10 608 3006 1997 66 2010 Wagoners 2011 n/a 53951 female 3/25/11 579 2800 1997 0 n/a 2010/11 Clark's Hill; 2011/12 n/a Not detected since tagging day 53953 male 2/25/11 690 4330 1997 413 2011 unknown, upstream of Hwy 172; 2012 unknown 2010/11 Clark's Hill; 2011/2012 Clark's Hill (S138, 144, 134, 123) 53955 male 3/25/11 544 1990 CNL 65 male 3/25/11 566 2450 CNL 59 53958 male 3/4/11 555 2350 1997 4974 2010/11 Clark's Hill; 2011/2012 n/a 2010/11 Clark's Hill; 2011/12 Clark's Hill (unknown) 2010/11 Clark's Hill; 2011/12 Clark's Hill 53956 2011 Wagoners; 2012 n/a 2011 unknown, upstream of Hwy 281; 2012 unknown 2011 Hudson; 2012 unknown, upstream of Hwy 281 53959 male 3/25/11 535 1890 CNL 6 n/a 2010/11 Clark's Hill; 2011/2012 n/a 53961 female 3/19/10 570 2490 1997 2756 2010 Hudson, Wagoners; 2011 Wagoners, Hudson 2009/10 Clark's Hill; 2010/11 Clark's Hill (S134) Not detected after it started migration upstream in 2011 Detected at or near two spawning sites each season. Weight (g) 3434 Year Class* 1997 Number of Detections 12886 Spawning Locations 2010 Wagoners; 2011 Hudson, Wagoners Winter Locations 2009/10 Clark's Hill; 2010/11 Clark's Hill (S138/S144) 2009/10 Clark's Hill; 2010/11 n/a Comments Page 17
Table 5. Summary of spawning and wintering locations for tagged fish in the Broad River system and Clark’s Hill Reservoir. ID 53962 Sex female Tag Day 3/19/10 Total Length (mm) 563 53963 female 3/25/11 620 3340 CNL 80 53964 male 3/19/10 590 2614 1997 37664 2010 Wagoners; 2011 Hudson 53965 male 3/19/10 541 2442 1997 10309 2010 Hudson; 2011 Hudson 53966 male 3/25/11 566 2360 1997 136 53967 male 2/25/11 662 4126 1997 23350 53971 male 3/25/11 564 2400 1997 0 Weight (g) 2890 Year Class* 1997 Number of Detections 77 Spawning Locations 2010 Hudson; 2011 Hudson Winter Locations 2009/10 Clark's Hill; 2010/11 Clark's Hill (S134); fall 2011 Clark's Hill (S134) 2011 Hudson; 2012 Hudson 2010/11 Clark's Hill; 2011/12 Clark's Hill (unknown) 2009/10 Clark's Hill; 2010/11 Clark's Hill (S144); fall 2011 Clark's Hill (S144) 2009/10 Clark's Hill; 2010/11 Clark's Hill (S138/S144) 2010/11 Clark's Hill; 2011/12 Clark's Hill (unknown) 2011 Wagoners; 2012 Wagoners 2010/11 Clark's Hill; 2011/2012 Clark's Hill (S138, 144); 2012/13 Clark's Hill n/a n/a Tag lost, did not move since tagging day. 2011 unknown, upstream of Hwy 172; 2012 unknown, upstream of Hwy 281 Comments Page 18
Table 5. Summary of spawning and wintering locations for tagged fish in the Broad River system and Clark’s Hill Reservoir. ID 53972 Sex male Tag Day 3/4/11 Total Length (mm) 564 53974 female 3/25/11 615 3350 1997 344 53975 male 3/25/11 563 2740 CNL 6 53977 male 3/25/11 610 3420 1997 131 Weight (g) 2470 Year Class* 1997 Number of Detections 317 Spawning Locations 2011 unknown, upstream of Hwy 172; 2012 unknown, upstream of Hwy 172 Winter Locations 2010/11 Clark's Hill; 2011/12 -‐ river?? Comments Not detected downstream of Hwy 172 in the winter of 2011/12 2011 unknown, upstream of Hwy 172; 2012 unknown, upstream of Hwy 172 2010/11 Clark's Hill; 2011/12 -‐ river?? Not detected downstream of Hwy 172 in the winter of 2011/12. n/a 2010/11 Clark's Hill; 2011 unknown, upstream of Hwy 172; 2012 unknown, upstream of Hwy 172 2010/11 Clark's Hill; 2011/12 Clark's Hill (S138, 144) Not detected after it started migration upstream in 2011 * CNL – Could Not Locate coded wire tag to determine year class. Page 19
Broad River Robust Redhorse reintroduction status During the fall-‐winter of 2010-‐2011, five of the six fish that received transmitters in 2010 returned to spend the winter in Clark’s Hill Reservoir. The sixth individual (53949) was one that was not detected after the spawning season. The two females (53961 and 53962) both spent the winter downstream of the Broad River mouth. Both were detected in fall by the S134 buoy and again in the late winter at the same buoy (Figure 8). The three remaining fish, all males (53948, 53964, and 53965) were detected in the area upstream of the Broad River mouth between buoys S138 and S144. Figure 9. Movements of the six Robust Redhorse captured in 2010. River kilometer 0 was arbitrarily placed at Anthony Shoals with positive numbers upstream into the river and negative numbers indicating movements into the reservoir. Solid lines represent males and dashed lines represent females. The dashed gray line at 71 river km represents the lowest known spawning location within the system. For six fish captured and tagged in 2010, all individuals showed similarities in movements within the reservoir and river (Figure 9). After tagging, all fish proceeded to move upstream of the tagging location to spawning shoals they occupied in May of 2010. Downstream migration tended to be less directed with the two females leaving the spawning area before the males and taking longer to reach the reservoir. The fish all tended to move from wintering locations to the area around Page 20
Broad River Robust Redhorse reintroduction status Anthony Shoals in February and March of 2011 and began the river portion of their migrations in mid-‐late March and early April. Movement patterns of the 12 fish tagged and detected at numerous stations in 2011 were less consistent than those fish tagged in 2010 (Figure 10), but overall pattern of upstream migration to the spawning sites was similar to that of the fish in 2010. Two fish were not graphed because of no detections with one individual (53951) and a stationary signal of the other (53971). One individual, a male (53972), moved back into the main body of the reservoir after being tagged. Prior to its main migration upstream toward the spawning shoals, this male made two different moves up toward the area around Anthony Shoals adding over 40 km of movement from the tagging day to when it began its main migration. During the winter of 2011-‐2012, two individuals, a male and female (53972 and 53974), were not detected downstream of Highway 172 during the winter, but recorded at the Highway 172 station the following spring. This would require passing at least one receiver within the river and the receiver at Highway 79 during both their downstream and upstream migrations without being detected. Because of low flows during this fall/winter season, it is possible these two individuals remained within the lower reaches of the river during the winter season. We only have two records fish by-‐
passing the Highway 79 receiver undetected (and only during downstream passage). Tests indicate that unless the receiver was buried within sediment or non-‐functional (dead battery), it should have detected any fish passing the constriction in river width at this locality. Although the receiver at Highway 79 has detected passing individuals when pool elevation levels were below 320 ft-‐msl these lower water levels might interfere with detection, especially if a fish passes on the far side of the channel from the receiver (Figure 11). Page 21
Broad River Robust Redhorse reintroduction status Figure 10. Movements of the twelve Robust Redhorse captured in 2011. River kilometer 0 was arbitrarily placed at Anthony Shoals with positive numbers upstream into the river and negative numbers indicating movements into the reservoir. Solid lines represent males and dashed lines represent females. The dashed gray line at 71 river km represents the lowest known spawning location within the system. Figure 11. Pool elevation (FT-‐MSL) in Thurmond Reservoir (Clark’s Hill) from January 2010 to January 2011. Page 22
Broad River Robust Redhorse reintroduction status We successfully documented four individuals using manual tracking during the first winter of the study. These fish were all found upstream of the Broad River mouth in the vicinity of mid-‐channel buoys S-‐138 and S-‐144 (at the mouth of Russell Creek). We did not manually locate any fish that moved downstream of the Broad River mouth. In all instances where these four individuals were located within the main reservoir, they were detected in water 5-‐9 m in depth, bottom sediments were fines, and they were associated with woody material. In these cases, except one, the fish were associated with the large amounts of remnant, standing, submerged trees along the river left side of the main channel markers in the reservoir (approximately 50-‐100 m from the shoreline). In one case the individual was associated with a large mass of woody material lying on the bottom, but within 15 m of the shoreline. We took one dredge sample to assess food conditions within the substrate and noted several large, live Asian clams (Corbicula fluminea) 2.5 -‐ 3.5 cm in width and numerous live chironmid larvae. Figure 12. Movements of four individual Robust Redhorse within Clark’s Hill Reservoir. Distances up and down represent relative distances upstream and downstream of the Broad River mouth within the main portion of the reservoir. Page 23
Broad River Robust Redhorse reintroduction status The four individuals found during manual tracking over-‐wintered in areas around stationary receivers within the reservoir (53948, 53964, 53965, and 653967; Figure 12). These fish spent large portions of their wintertime near existing receiver stations, but also moved between receiver stations (movements of 3.1 km between S-‐138 and S-‐144 and 5.5 km between S-‐144 and S-‐134). Within each of these periods where fish are being detected at a single station are gaps as the fish are moving in and out of the receiver range. Time of Day Using detections at stationary receivers only, we estimated the time of day individual Robust Redhorse were actively moving within the reservoir, river, and within the spawning shoals. We used any detection that was at least 12 minutes (four cycles of the maximum transmitter cycle time). This indicates that the fish would have actively moved to within detection range of the receiver during this event (as opposed to being stationary or having some short amount of interference causing the appearance of movement). Of 93,699 detections, 5,986 events met the requirements for this analysis. Using a Chi-‐square test of independence, we tested differences of frequency of movements between males and females at different times of day. We also tested difference between classes of locations (reservoir, river, spawning shoal) for females and for males. Male and females had movements at different times of day than expected (!2 = 80.84, df = 11, p < 0.0001; Figure 13). Females appear to make fewer movements in the early hours around and after dawn (from 5:00 am until 9:00 am). We broke the data set into locality classes based on the location where the detection occurred, i.e. in the reservoir (winter), in the river (typically detections as fish are migrating upstream and downstream from the spawning shoals, and in the vicinity of the spawning shoals. The receivers in the vicinity of the spawning shoals were located typically in a deeper hole either immediately downstream of the spawning area or between spawning patches of a spawning shoal. These spawning vicinity detections may either indicate individuals moving out of the main spawning aggregation (possibly resting) or moving between spawning patches. Comparing movements that occurred in reservoirs, rivers, and in the vicinity of the spawning site males showed a difference in the time of day (!2 = 61.41, df = 22, p < 0.0001; Figure 14A). In general, males movements within the spawning areas and reservoir occurred least often in the late evening / early morning, between 2300 and 2:00 am. Movements within the river tended to be more uniform relative to the time of day. We compared female movements using just river and reservoir movements. The number of Page 24
Broad River Robust Redhorse reintroduction status movements within the vicinity of the spawning shoals are shown for comparison, but sample sizes were too small for analysis. Females showed no difference in time of day in movements (!2 = 10.43, df = 22, p = 0.49; Figure 14B). Figure 13. Percentage of movements of female and male Robust Redhorse by time of day (partitioned by two hours). Comparing just movements that occurred within the reservoir, males and females showed differences in the time of day movements occurred (!2 = 73.86, df = 11, p < 0.0001; Figure 15). Females tended to have the fewest number of movements in the late-‐afternoon and early evening hours (3:00pm until 6:00pm). Males had their peak number of movements in the mid-‐ to late-‐
morning (7:00am until 1:00pm). Comparing river movements, most of which correspond to the season when fish were migrating to and from the spawning shoals, showed no difference in the time of day movements were made between males and females (!2 = 15.2, df = 11, p = 0.1731; Figure 16). This lack of difference may correspond to a need to maintain movement upstream or downstream or to reach a specific destination by a specific time. Page 25
Broad River Robust Redhorse reintroduction status Because sample sizes were small for movements within the vicinity of the spawning shoals, we could not perform any analyses (Figure 17). If these trends hold true with larger sample sizes, it would appear that females made a large number of movements in the middle of the night (11:00pm until 1:00am). This behavior may correspond to a quiet period in the spawning efforts of fish (see Reproduction for details on spawning and time of day). Figure 14. Percentage of A. male and B. female movements within the reservoir, river, and in the vicinity of the spawning shoal by time of day (partitioned by two hours). Page 26
Broad River Robust Redhorse reintroduction status Figure 15. Percentage of female and male Robust Redhorse movements within the reservoir (winter) by time of day (partitioned by two hours). Figure 16. Percentage of female and male Robust Redhorse movements within the river (migration) by time of day (partitioned by two hours). Page 27
Broad River Robust Redhorse reintroduction status Figure 17. Percentage of female and male Robust Redhorse movements in the vicinity of the spawning shoal by time of day (partitioned by two hours). Travel Distance and Speeds All of the transmittered fish that we had detections for travelled between 55 and 98.5 river km between winter and spawning locations within the system (Table 6). Assuming some fish using the most upstream known spawning site (North Fork) also winter within Clark’s Hill Reservoir the migration distance would be over 100 river km. Since most detections used stationary receivers, we estimated travel speeds using known distances between these stations. We chose to limit the data set to only paired detections that occurred within 30 days of one another to minimize records where a fish was not travelling, but spending time resting, foraging or other activities. Although this method has error in the distance between stations and assumptions about fish using straight-‐
line travel, this provides some general reference, for travel rates when estimating transit times from area to area. Page 28
Broad River Robust Redhorse reintroduction status Table 6. Average, range (minimum -‐ maximum) and standard deviation of travel speeds (km/hr) and distances between the most upstream and downstream detections for transmittered Robust Redhorse. Travel speeds were calculated between two known localities with detections less than 30 days apart. Sex Reservoir Fish ID N Female Average; Range (SD) (km/hr) 53961 1 0.04 53962 4 0.39; 0.04-‐0.75 (0.37) 53963 0 53974 0 Male 53948 4 53949 0 53953 1
2 53955 0 53956 0 53958 0 53959 0 53964 7 53965 2 53967 4 53972 6 53975 0 53977 4 53966 1 N 1; 0.08-‐2 (0.98) 1.84; 0.05-‐8.79 (2.42) 0.22; 0.01-‐0.68 (0.25) 1; range: 0.3-‐1.71 (1) 0.13; 0.05-‐0.2 (0.07) 0.1; 0.03-‐0.24 (0.07) 0.47; 0.01-‐1.8 (0.88) 0.01; 0.01-‐0.01 (0) Downstream 6 3 3 0 3 2 1 0 0 0 0 2 2 4 Average; Range (SD) (km/hr) 1.07; 0.16-‐2.31 (0.9) 0.83; 0.35-‐1.67 (0.73) 0.04; 0.02-‐0.06 (0.02) 0.1; 0.04-‐0.18 (0.07) 1.2; 1.13-‐1.27 (0.1) 2.49 0 0.52; 0.07-‐0.98 (0.64) 1 1.58; 0.75-‐2.41 (1.17) 0.04; range: 0.03-‐
0.05 (0.01) 0.23; 0.08-‐0.48 (0.18) 0.06 Upstream N 0 2 12 5 7 1 10 4 1 4 3 5 1 9 7 4 Max. Average; Distance Range (SD) (km/hr) (km) 2.21; 0.03-‐22.25 (6.32) 0.35; 0.04-‐0.82 (0.32) 0.12; 0.01-‐0.24 (0.09) 0.21 94.38 0.09; 0.01-‐0.29 (0.08) 0.12; 0.03-‐0.18 (0.06) 98.48 0.10 71.03 0.27; 0.03-‐0.51 (0.2) 0.16; 0.04-‐0.41 (0.21) 0.23; 0.02-‐0.47 (0.16) 0.49 0.14; 0.02-‐0.35 (0.11) 0.09; 0.03-‐0.22 (0.07) 0.09; 0.02-‐0.14 (0.05) 90.88 83.38 55.43 81.63 84.58 72.5 82.28 55.43 98.48 91.98 86.58 0 1 0.32 0.3; 0.02-‐0.47 (0.24) 0.16; 0.04-‐0.3 (0.11) 69.33 3 5 55.43 69.33 Page 29
Broad River Robust Redhorse reintroduction status Reproduction Spawning Sites From 2007 to 2012, we documented Robust Redhorse spawning at six distinct localities in the Broad River System (Figure 18; Table 7). These localities will be referred for the remainder of the report as Hudson (Hudson River upstream of Highway 29), North Fork (North Fork Broad River), Wagoners (Broad River upstream of Highway 29), Broad ds (Broad River downstream of the Wagoners site), Power line (Broad River downstream of Highway 29 and upstream of Highway 281), and Broad us 281 (Broad River downstream of the Power line site and upstream of Highway 281). All of these localities (except Power line) were accessed with the permission of the property owners with the understanding that the specific localities would not be publically available and would help with conservation of Robust Redhorse. Information about spawning population size can be found on page 65. North Fork Wagoners Broad d s Hudson Power line Broad u s 281 Figure 18. Spawning localities (yellow indicators) and their abbreviated names (used within the text) of Robust Redhorse in the Broad River watershed used from 2007 to 2012. Page 30
Broad River Robust Redhorse reintroduction status Table 7. Spawning site use by year by Robust Redhorse in the Broad River system from 2007 until 2012. Locality 2007 2008 2009* 2010 2011 2012 Hudson X X NA X X X North Fork NA NA NA X X 0 Broad (Wagoners) X X NA X X X Broad (ds) NA NA NA NA NA X Broad (Power line) X 0 NA NA 0 X Broad (us 281) NA NA NA NA NA X X – site was used during this season, 0 – site was checked and determined not to be used, NA – site was not searched or known during this season. * Water levels were too high and water too turbid to perform visual observations during this spawning season. In all cases, spawning localities were found through visual surveys of the Broad River system via canoe. In our original exploratory season in 2007, we documented three localities, Wagoners, Hudson and Power line, where spawning Robust Redhorse were observed between 17-‐20 May (Table 7). Robust Redhorse used two of these three sites each year we were able to observe fish during the spawning season (2010, 2011, 2012; Hudson and Wagoners). Because of time involved in access of the additional site found in 2007 (Power line), we only visited this site once each season to determine if there was evidence of active or recent spawning. In 2007, we noted fish at both this locality and the site at Wagoners were actively spawning. We attempted to visit this site when spawning was close to its peak at the Wagoners and Hudson locations, assuming that fish would be present or recently active at this locality if it was used. This site visit was conducted in conjunction with a survey of the Broad River between the North Fork at Highway 145 downstream to the Broad River Outpost, just downstream of Highway 281. This visual survey was conducted each year (2007, 2008, 2010, 2011, and 2012) to look for any additional unknown spawning locations (or evidence of spawning) and in later years also to check known deeper holes for tagged Robust Redhorse. Surprisingly, we only found Robust Redhorse at known spawning sites (except in 2007). At the site upstream of Highway 281, Robust Redhorse were in fairly swift deep water and could have been overlooked in some years depending on the route used to pass through the bedrock ledge, which could take you along the opposite bank of the river through pool-‐like habitat with sandy substrates. Typically, evidence of spawning activity from suckers using a site earlier Page 31
Broad River Robust Redhorse reintroduction status within the spring (i.e. Minytrema melanops) starts to fill in with sediment before Robust Redhorse began spawning in each of the three observation years. Fresh, clean spawning lenses (pits) indicated recent spawning activity (Figure 19). Figure 19. Typical spawning lens (three lenses visible, noted with red arrows) created through the act of repeated spawning by Robust Redhorse within the Broad River system. In 2009, high water levels and resulting high turbidity in the system prohibited observations during the spawning period. In 2010, we documented a new site (North Fork) used by Robust Redhorse. We documented both Minytrema melanops and Moxostoma collapsum using this site earlier in 2008, but Robust Redhorse were not seen. In the spring of 2012, we documented an additional two localities, the site upstream of Highway 281 (Broad us 281) and the site on the Broad River upstream of Highway 29 and approximately 200 m downstream of a previously used site (Broad ds). At the beginning of the 2012 spawning season, we investigated a bedrock ledge that spans most of the river at the Broad us 281 locality to determine if the ledge could be a barrier to upstream migration for Robust Redhorse given the low flows at the time. After searching this location, fish were found holding and spawning on the river left margin of the river downstream of the bedrock ledge. There was also evidence, spawning pits in sandy substrate that was filling in with fine sediment, which indicated Minytrema melanops likely also spawned in areas around this Page 32
Broad River Robust Redhorse reintroduction status site earlier in the spring. The area used by Robust Redhorse at this site had substrate similar to that used at other spawning sites in the system (see Spawning Sites). While conducting juvenile sampling in the fall of 2011, we noticed a large amount of gravel visible because of low flows downstream of the Wagoners site. During the 2012 season, we visited this patch of gravel and documented its use by Robust Redhorse. Spawning Season During the course of this study we documented spawning by Robust Redhorse, Spotted Sucker (Minytrema melanops), Brassy Jumprocks (Moxostoma sp.), Notchlip Redhorse (Moxostoma collapsum), and Northern Hogsuckers (Hypentelium nigricans). We monitored three Robust Redhorse spawning sites multiple times within the spawning seasons of 2010 to 2012 (Hudson, North Fork, and Wagoners). Using the timing of spawning related to other sucker species in the system, we estimated when to initiate a concentrated effort to check sites (see Figure 20). Since the new spawning sites upstream of Highway 281 on the Broad River and the Broad ds site were located after spawning had already begun, we could not determine exact start of the season for those localities. Timing The earliest known spawning season for Robust Redhorse in the Broad River system was in 2012 and started on 26 April and the latest known date of spawning occurred in both 2010 and 2011 on 23 May. Spawning period of Robust Redhorse in other systems occurs in the early spring, and varies from year to year, likely based on differences in temperature and other water conditions (Table 8). Within the Pee Dee and Wateree, Ocmulgee and Ogeechee Rivers spawning observations has been limited, with most spawning periods based on captures of fish in spawning condition (no mucus coat, spawning injuries, tubercles, and expressing either eggs or milt with little or no pressure on the abdomen) near either known or suspected spawning localities. Spawning observations, have been made for numerous years in the Oconee and Savannah Rivers (Table 8). Based on observations in all of the basins spawning may have occurred as early as 23 April and as late as 31 May, and possibly into early June. Our observations within the Broad River fit within this range of dates. Page 33
Broad River Robust Redhorse reintroduction status Table 8. Dates of known or suspected spawning of Robust Redhorse in various basins where it occurs. Dates Year Basin Locale Source 5/10 -‐ 5/22 2010 Broad River, GA North Fork CAS 5/11 -‐ 5/19 5/10 -‐ 5/23 5/7 -‐ 5/21 5/3 -‐ 5/17 5/3 -‐ 5/23 4/30 -‐ 5/7 4/26 -‐ 5/7 4/26 -‐ 5/7 5/19 -‐ 2010 2010 2011 2011 2011 2012 2012 2012 2005 Broad River, GA Broad River, GA Broad River, GA Broad River, GA Broad River, GA Broad River, GA Broad River, GA Broad River, GA Ocmulgee* Hudson Wagoners North Fork Hudson Wagoners Hudson Wagoners Broad (us 281) ds Juliette dam CAS CAS CAS CAS CAS CAS CAS CAS BJF, CAS 5/14 -‐ 5/22 1995 Oconee* Avant 5/20 -‐ 1996 Oconee* Avant 5/10 -‐ 5/13 1997 Oconee* Avant 5/17 -‐ 5/19 1998 Oconee* Avant 4/27 -‐ 5/18 1999 Oconee* Avant 4/23 -‐ 5/4 2000 Oconee* Avant 5/2 -‐ 5/15 4/28 -‐ 5/5 -‐ 5/4 -‐ 5/8 5/8 -‐ 5/17 5/3 -‐ 5/12 4/30 -‐ 5/14 5/6 -‐ 5/7 before 6/9 2001 2002 2003 2004 2005 2006 2007 2008 2009 Oconee* Oconee* Oconee* Oconee* Oconee* Oconee* Oconee* Oconee* Ogeechee Avant Avant Avant Avant Avant Avant Avant Avant DS of Highway 1 at Louisville Freeman and Freeman 2001 Freeman and Freeman 2001 Freeman and Freeman 2001 Freeman and Freeman 2001 Freeman and Freeman 2001 Freeman and Freeman 2001 BJF, CAS BJF BJF BJF, CAS BJF, CAS CAS CAS CAS RRCC ITTWG database 5/12 -‐ 5/20 2011 Ogeechee rkm 306.6 5/5 -‐ 5/10 2005 Pee Dee* P. Ely, unpublished data RRCC ITTWG database Comments Likely spawning, males holding position Capture of a fish in at the end of spawning condition. Based on condition of captured Robust Redhorse in the vicinity of a suspected spawning area. Page 34
Broad River Robust Redhorse reintroduction status Dates 4/25 -‐ 5/8 Year 2006 Basin Pee Dee* Locale Source RRCC ITTWG database 4/26 -‐ 5/2 2007 Pee Dee* RRCC ITTWG database 4/23 -‐ 5/7 2008 Pee Dee* RRCC ITTWG database 4/29 -‐ 5/12 2009 Pee Dee* RRCC ITTWG database 4/15 -‐ 5/15 Pee Dee* below Blewett Falls Fisk 2010 5/25 -‐ 5/26 1999 Savannah* 5/31 -‐ 2000 Savannah* NSBL&D 5/20 -‐ 2001 Savannah* 5/6 -‐ 2002 Savannah* upper bar 5/2 -‐ 5/15 2004 Savannah* lower bar 5/9 -‐ 5/15 2004 Savannah* upper bar 5/7 -‐ 5/18 2005 Savannah* lower bar 5/9 -‐ 5/16 2005 Savannah* upper bar 4/28 -‐ 2006 Savannah* 5/2 -‐ 2007 Savannah* 5/1 -‐ 2008 Savannah* 5/6 -‐ 2009 Savannah* 5/13 -‐ 2010 Savannah* RRCC ITTWG database Freeman and Freeman 2001 RRCC ITTWG database J. Isley, pers. comm. Grabowski 2006 Grabowski 2006 Grabowski 2006 Grabowski 2006 RRCC ITTWG database RRCC ITTWG database RRCC ITTWG database RRCC ITTWG database RRCC ITTWG database Comments Based on condition of captured Robust Redhorse in the vicinity of a suspected spawning area. Based on condition of captured Robust Redhorse in the vicinity of a suspected spawning area. Based on condition of captured Robust Redhorse in the vicinity of a suspected spawning area. Based on condition of captured Robust Redhorse in the vicinity of a suspected spawning area. No actual spawning observed, fish in spawning condition in appropriate spawning habitat. Page 35
Broad River Robust Redhorse reintroduction status Dates 5/12 -‐ Year 2011 Basin Savannah* Locale before 4/25 2012 Savannah* lower bar 5/5 -‐ 2010 Wateree* Source RRCC ITTWG database RRCC Annual Meeting 2012, Scott Lamprecht RRCC Annual Meeting 2012, Dave Coughlan Comments Fish captured for broodstock appeared past viable egg production. Potential spawning * Flows and temperature in these localities are modified by hydrological management upstream of the spawning area. The timing of spawning within the Broad River system generally followed the same order every year, except in 2012. Generally, Spotted Suckers spawn first followed by Notchlip Redhorse, Northern Hogsuckers, Brassy Jumprocks, and finally Robust Redhorse (Figure 20). In 2012, this order was followed, but the beginning of the spawning season started earlier than normal and species overlapped more in spawning period, which was likely caused by higher spring water temperatures. Also, we first documented spawning Northern Hogsuckers and Brassy Jumprocks in 2012. The compressed spawning season early in 2012 may have led to higher visibility of spawning Brassy Jumprocks. Two groups of Brassy Jumprocks (spawning trios) were observed in 2012 in areas that would be later used by robust redhorse or have been used by robust redhorse in the past. Northern Hogsuckers were also seen in areas that either would later be used by robust redhorse or had been used by robust redhorse in the past. In previous seasons, we observed Brassy Jumprocks in the vicinity of spawning shoals, but never witnessed spawning events. Typically, Spotted Suckers and Notchlip Redhorse would overlap some in the timing of spawning, but partitioned habitat within a site (Figure 21). We calculated the length of the spawning season (days) based on first observation of spawning fish at a site and the last observation of spawning individuals at a site. The spawning season lasted approximately 15 days in 2010, 21 days in 2011, and 12 days in 2012 (Figure 22). The water temperatures were warmer earlier in 2012 and may have resulted in this compressed length of the spawning season. Page 36
Broad River Robust Redhorse reintroduction status Figure 20. Timing of spawning season for Moxostoma robustum, M. sp. “brassy”, M. collapsum, Minytrema melanops, and Hypentelium nigricans in the Broad River, Georgia. OW
FL
Figure 21. Conceptual diagram of the spawning shoal at Wagoners. Top and bottom gray lines indicate river right and river left banks, respectively. Brown areas indicate exposed gravel islands. Gray chevron-‐shapes in the upstream indicate bedrock ledges and gray, mottled shapes indicate areas of submerged spawning gravel consistent with the size used by Robust Redhorse. Areas of purple indicate spawning use areas by Spotted Suckers. Notchlip Redhorse used the area with orange. Robust Redhorse used areas in red. Page 37
Broad River Robust Redhorse reintroduction status Figure 22. Spawning period for Robust Redhorse (Moxostoma robustum) at four localities in the Broad River system from 2010 to 2012. In the Savannah River downstream of New Savannah Bluff Lock and Dam, Grabowski and Isley (2007) recorded a progression in the timing of spawning suckers as Northern Hogsucker, Notchlip Redhorse, Spotted Sucker, Carpsucker, and Robust Redhorse. This progression is different then what we saw at our locality; however, spawning individuals within the Savannah River downstream of Clark’s Hill Reservoir are migrating and spawning in an environment (flow and temperature) altered by operations of Thurmond Dam. We did not observe any carpsuckers spawning; however, we did capture young-‐of-‐year carpsuckers in our fall sampling (see Juvenile Sampling). Tagged fish arrival at spawning sites. In the vicinity of the spawning shoals, we began detecting tagged individuals almost a month prior to when we visually observed spawning. The first tagged fish arrived 19 days before spawning started in 2010 (female), 24 days before in 2011 (same female as in 2010), and 25 days before in 2012 (male). Most areas within the spawning shoals had depths that allowed us to determine use (holding or spawning fish) by visual observation or physically moving through the habitat. Observations at the spawning site typically revealed one or two Robust Redhorse moving through or holding near the spawning sites within the week of spawning. Page 38
Broad River Robust Redhorse reintroduction status Spawning Microhabitat During the spawning period we attempted to measure water temperature daily. Although temperatures (and depths and velocities in the following section) are not independent within years, we present the data as means, SE and sample sizes within the year. The variation between species in temperature typically related to the time of season each of the species spawned, with Spotted Suckers having the lowest temperatures each year followed by Notchlip Suckers, then Robust Redhorse (Table 9). Temperatures used by Robust Redhorse through the years ranged from 16-‐
24.6 °C. These temperatures were within the range (17-‐26.7 °C) reported by Freeman and Freeman (2001) and also similar to the range (17.5-‐22.1 °C) reported by Fisk (2010) for Robust Redhorse in the Pee Dee River. Table 9. Average temperature (degrees C) with sample size, range, and standard error (N; range; SE) for Spotted Suckers, Notchlip Suckers, Robust Redhorse, and Northern Hogsuckers in the Broad River system from 2007-‐2012. Year 2007 Minytrema melanops na 2008 18.1 (2; 17.9-‐18.3; 0.2) 2010 19.25 (3; 19-‐19.75; 0.25) 2011 16 (2; 15-‐17; 1) 2012 19.78 (5; 16.5-‐21; 0.83) Moxostoma collapsum 17.8 (1; na; na) Moxostoma robustum 20.55 (2; 20-‐21.1; 0.55) 22 (3; 21-‐23; 0.58) Hypentelium nigricans na na 16.75 (2; 16.5-‐15; 0.25) 20.11 (12; 16.3-‐22; 0.54) 19.38 (26; 16-‐23.1; 0.43) 20.75 (2; 20.5-‐21; 0.25) 22.10 (14; 18.6-‐24.6; 0.46) 18.69 (3; 16.7-‐21; 1.08) 19.9 (1; na; na) na na na Depth / Velocity. Depth and velocities were measured periodically throughout the spawning season using a wading rod and electronic current meter (Marsh-‐McBirney). Velocities were measured at the bottom and at 60% of water depth, measured from the water surface. We measured depths and velocity during the spawning seasons as the overall flow in the river changed and locations of areas used shifted. We attempted to measure velocity and depth at positions where we saw spawning events occur. Additionally, we measured velocities in areas where we discovered females holding position while not involved in spawning activities. Robust redhorse used depths that ranged from 0.15 to 0.88m with an average of 0.49m (Table 10). These were on average deeper than sites used by Page 39
Broad River Robust Redhorse reintroduction status Spotted Suckers and Notchlip Redhorse in the Broad River system, but less than the average depth of sites used by River Redhorse in the Coosawattee River in 2012 (CAS unpublished data). The measured depths in the Broad River were less than the range (0.29 to 1.04 m) reported for the Oconee by Freeman and Freeman (2001) and less than the average (0.74 m) reported by Grabowski and Isley (2007) for the Savannah River. Spawning site depths listed in Fisk (2010) were also deeper (1.0-‐1.5 m) than those seen within the Broad River system. Table 10. Depths (m) and water velocities (Bottom and 60%) at spawning sites used by Spotted Suckers, Notchlip Redhorse, Robust Redhorse and River Redhorse from 2008-‐
2012 (excluding 2009 when no measurements were taken). River redhorse measurements are only from 2012. N Depth (m) Velocity Bottom (m/s) Velocity 60% (m/s) Minytrema melanops 50 0.36 (0.02) 0.29 (0.02) 0.58 (0.03) Moxostoma collapsum 26 0.29 (0.02) 0.37 (0.04) 0.71 (0.06) Moxostoma robustum 148 0.49 (0.01) 0.33 (0.02) 0.73 (0.02) Moxostoma carinatum 17 0.65 (0.03) 0.32 (0.03) 0.70 (0.03) Velocities at Robust Redhorse spawning localities ranged from -‐0.14 to 0.85 m/s on the bottom and 0.24-‐1.4 m/s at 60% of water depth. Water velocities at 60% of water depth for sites within the Oconee River ranged from 0.26 to 0.67 m/s (Freeman and Freeman 2001) and were an average of 0.24 m/s in the Savannah River (Grabowski and Isley 2007). In the Pee Dee River system, Fisk (2010) indicated that a velocity of 0.5 to 0.8 m/s was the mean velocity at their spawning sites. Based on these studies, it appears that Robust Redhorse in the Broad River system use spawning sites with a higher upper range of water velocities. These differences may be caused by higher slopes within some of the sites in the Broad River (local slopes were not measured during this study). The flow regimes at the spawning sites in the Oconee (below Sinclair Dam), Savannah (below Thurmond Dam) and Pee Dee (below Blewett Falls Dam) are all influenced by dam operations upstream of the spawning sites; therefore water depth and velocities at the sites are altered and could be less than optimal for spawning Robust Redhorse. However, flows were low during the course of this study, and lower flows may have influenced depths and velocities available for spawning with the Broad River system (Figure 23). Page 40
Broad River Robust Redhorse reintroduction status Figure 23. Mean monthly discharge (cfs) from 2002 to 2012 for USGS gage 02191300, Broad River at Carlton, Georgia. Data for Oct-‐Dec 2011 and all of 2012 were averaged from provisional data. Median flows were taken from data spanning 1899-‐1913 and 1997-‐2011. Table 11. Depths (m) and water velocities (bottom and 60%) at resting areas for females within spawning sites used by Spotted Suckers and Robust Redhorse from 2008-‐2012 (excluding 2009 when no measurements were taken). N Depth (m) Velocity Bottom (m/s) Velocity 60% (m/s) Minytrema melanops 8 0.34 (0.03) 0.01 (0.05) 0.19 (0.10) Moxostoma robustum 6 0.45 (0.02) 0.16 (0.09) 0.33 (0.16) Within the spawning sites, female suckers of territorial species (Spotted Suckers and Robust Redhorse) spent time when not spawning in areas away from males holding territories. These areas tended to have fine bed sediments and had velocities at the bottom (where the fish were sitting) that ranged from -‐0.17 to 0.24 m/s for Spotted Suckers and -‐0.13 to 0.49 for Robust Redhorse (Table 11). The areas with negative current velocities were typically within areas that had eddies creating a rotating flow behind large woody material or point bars. Page 41
Broad River Robust Redhorse reintroduction status Substrate. We took four grab samples (average dry mass of 1200 g) of bed substrates within each spawning patch to estimate the dominant particle size of spawning substrate for Robust Redhorse, Spotted Suckers, and Notchlip Redhorse. After the spawning season for each species was completed, but before large amounts of fine substrates started to fill in at the spawn substrates, we collected the samples from random locations within the downstream lens of elevated gravel created by spawning suckers. Because this gravel was moved during the process of spawning, sampling at that location should provide an accurate measure of substrate chosen. We dried and sieved the samples in <0.25mm (fines), 0.25-‐2.0 mm (sand), 2.0-‐4.75 mm (coarse sand, fine gravel), 4.75-‐12.5 mm (gravel), 12.5-‐50 mm (coarse gravel), and >50 mm (very coarse gravel, small cobble) size fractions. Although this method may lose a small portion of fines relative to freeze-‐core methods, we believe the larger-‐size portions accurately reflect substrate conditions at the spawning sites. Spawning gravel for Spotted Suckers showed similarity between years and no dominate category (Figure 24A). Spotted Suckers have the most consistent use in substrate categories between sand and coarse gravel categories (0.25-‐50mm) with the largest class (coarse gravel; 12.5-‐50mm) in this range being the largest portion by weight. Spawning substrates for Notchlip Redhorse and Robust Redhorse were dominated by the coarse gravel (12.5-‐50mm) size class (Figure 24B and C, respectively). The proportion of all species by year contained less than 1.5% fine sediments by weight (<0.25mm). The proportions of spawning substrate classes used by robust redhorse are similar to those found by Freeman and Freeman (2001). Similar dominant gravel sizes also occur at the spawning sites in the Savannah River (Freeman and Freeman 2001; Jackson and Long 2011). Page 42
Broad River Robust Redhorse reintroduction status Figure 24. Substrate fractions (mm) used at spawning sites for Spotted Suckers, Notchlip Redhorse, and Robust Redhorse in 2010, 2011, and 2012. Proportions represent the percent of the total weight for each year. Sample size represents the total number of spawning patches, with four samples taken within each patch. Page 43
Broad River Robust Redhorse reintroduction status Anecdotal Information / Behavior Signs of spawning Robust Redhorse include large patches of cleared, relatively large-‐sized gravel. Initially the bed level of these cleared areas will be relatively smooth. Elevation differences became pronounced where spawning activities had been repeated. As the season progresses, spawning areas continually get reused creating large lenses of elevated gravel with depressions in front of them (Figure 19). These lenses / pits can be over 0.5 m in depth, but can also made by other large-‐bodied, territorial suckers, e.g. Spotted Suckers and River Redhorse. Within the Broad River system, we found no evidence of large lenses of gravel from spawning Notchlip Redhorse. The only evidence created by spawning Notchlip Redhorse appeared to be a “cleaned” appearance of gravel used during spawning. Male Robust Redhorse typically held and defended territories, while females spent most of their time in flow refugia over fine sediments away from the males. These areas included backwater areas created by projections of a bank or point bars or by large woody material or bedrock ledges. If a female chose to rest within the spawning shoal, she typically chose areas immediately downstream of the spawning gravel lens created by the spawning act. The flows directly behind these lenses were usually 0 m/s or eddies, providing refugia from flow. Typical spawning behavior for Robust Redhorse within the Broad River spawning sites consisted of spawning trios (two males, one flanking either side of a female). Spawning trios are typical for Catostomid species (Page and Johnston 1990). Commonly additional males would rush in on either side of the exterior males or try to displace a flanking male. Typically when additional males approached, the spawning act would be disrupted (except late in the spawning season). When competing males approached a spawning trio, a flanking male on the side of the approaching male might break off from the spawning activity to push the approaching male from the spawning group. This “release” from the spawning act typically caused the female to stop vibrating and the spawning act to cease. On occasion, normally at the peak or later in the spawning season, the additional male was allowed to participate without disturbing the spawning act, usually flanking one male (making a spawning quad). Rarely, we observed a spawning duo where an individual female and male appeared to go through spawning motions, although the release of eggs and sperm was not documented. This was typically seen very late in the season when only a few or a pair of individuals were seen at a site. Page 44
Broad River Robust Redhorse reintroduction status On a few occasions (in 2010), we observed spawning quints, where five robust redhorse attempted to spawn in unison. The spawning group formed in a male, female, male, female, male organization where each female was flanked by a male on either side, with the center male having females on both sides. Another quint spawning group, seen on one occasion was a male, male, female, male, male organization. This unusual organization also occurred in the last half of the spawning season when the remaining spawning fish were compressed into a single patch. Habitat Partitioning Within each site Notchlip Redhorse typically used shallower, swifter areas for spawning. When Spotted Suckers and Notchlip Redhorse were spawning at the same time in 2012, these species segregated with Spotted Suckers typically using deeper areas with a variety of bed sediments (sand to gravel; Figure 21). Robust Redhorse spawning never overlapped with Spotted Suckers in timing. However, if stream flows did not displace substrata, Robust Redhorse would spawn over existing spawning lenses created by Spotted Suckers (if the substrate was within the range used by Robust Redhorse). As water levels dropped during the spawning season, spawning Robust Redhorse shifted into deeper water leaving previous sites unoccupied allowing fine sediments to begin covering the gravel. Recruitment Juvenile Sampling To assess recruitment of Robust Redhorse within the Broad River system, we conducted juvenile sampling in the fall of 2009 and 2011. Since no capture records of young-‐of-‐year (YOY) Robust Redhorse exist beyond the larval stage in any river system, we developed a sampling design to assess a variety of locations and habitat in the system during 2009. In 2011, we modified this design to focus efforts farther upstream in the system. Methods Site Selection. In 2009, we plotted points every 250m on the 1:100,000 NHD from Anthony Shoals upstream to the North Fork at the Royston water facility dam, Middle Fork at Highway 106, and Hudson River at Highway 106. We used a random generation to choose (each site receives a 0 or 1) to eliminate all sites with 0’s. We randomly selected 31 of the possible 504 sites. Given a limited amount of time we sampled 14 of these sites in the fall of 2009 (Table 12). Page 45
Broad River Robust Redhorse reintroduction status Table 12. Juvenile sampling sites sampled in 2009. Last column represents young-‐of-‐year (YOY) Jumprocks (Moxostoma sp. and Moxostoma rupiscartes), Spotted Suckers (Minytrema melanops), and Notchlip Redhorse (Moxostoma collapsum) only. Latitude, Longitude 34.24763, -‐83.26105 YOY Suckers Captured Jumprock 1 Spotted 6 Notchlip 1 8/20/2009 34.24869, -‐83.26797 Spotted 6 Middle Fork at Harrison Bridge Road 9/10/2009 34.329828, -‐83.232543 Jumprock 2 Spotted 6 Notchlip 2 82 Middle Fork at State Route 51 (Sandy Cross Road). 9/15/2009 34.29201, -‐83.180743 Jumprock 1 87 Middle Fork at Atkinson Bridge Road 9/15/2009 34.31970, -‐83.21288 Spotted 4 134 Hudson River at State Route 106 9/10/2009 34.24908, -‐83.27109 Jumprock 2 Spotted 2 Notchlip 2 146 Hudson River at State Route 29 9/15/2009 34.23963, -‐83.179100 Jumprock 2 171 Broad River approx. 1.6 air miles upstream of State Route 281. 9/9/2009 34.19326, -‐83.15176 No YOY 172 Broad River approx. 1.7 air miles upstream of State Route 281. 8/25/2009 34.19445, -‐83.1539 No YOY 173 Broad River approx. 1.9 air miles upstream of State Route 281 8/25/2009 34.19652, -‐83.15455 Jumprock 1 182 Broad River approx. 3.3 air miles upstream of State Route 281 8/25/2009 34.20899, -‐83.16291 Jumprock 1 Spotted 1 197 Broad River approx. 0.1 river miles downstream of confluence of Hudson River Broad River approx. 1.8 river miles downstream of State Route 172 9/9/2009 34.23725, -‐83.17133 Notchlip 1 8/26/2009 34.14717, -‐83.06144 No YOY Locale Hudson River approx. 0.6 river miles downstream of State Route 106 Sample Date 8/20/2009 46 Hudson River, approx. 0.2 river miles downstream of State Route 106 64 43 288 Page 46
Broad River Robust Redhorse reintroduction status 289 Locale Broad River approx. 1.6 river miles downstream of State Route 172 Sample Date 8/26/2009 Latitude, Longitude 34.14888, -‐83.06226 YOY Suckers Captured No YOY 313 Broad River approx. 2.8 river miles upstream of State Route 77 9/11/2009 34.00763, -‐82.91469 No YOY 324 Broad River approx. 4.6 river miles upstream of State Route 77 9/11/2009 34.01422, -‐82.93574 No YOY 326 Broad River approx. 4.9 river miles upstream of State Route 77 9/11/2009 34.01449, -‐82.94089 No YOY 461 Broad River approx. 1.0 river miles downstream of State Route 17 8/19/2009 33.97222, -‐82.75384 No YOY 465 Broad River approx. 0.4 river miles downstream of State Route 17 8/19/2009 33.97323, -‐82.76437 No YOY Power Broad River at Power Line line spawning site 8/25/2009 Jumprock 2 Spotted 1 9/10/2009 34.34235, -‐83.25417 Jumprock 2 Spotted 6 Notchlip 2 Totals 502 Middle Fork of the Broad River at State Route 106 Jumprock -‐14 Spotted -‐32 Notchlip -‐8 In 2011, we chose to focus our fall juvenile sucker sampling in the upstream reaches of the Broad River system (in the vicinity of Highway 281 and upstream). We decided to focus on this upstream area because all YOY suckers captured in 2009 were captured in these reaches. We sampled 15 sites several of which were sampled during the day and at night (Table 13). We chose to sample sites at and within 1000 m downstream of each spawning location used in 2011. We also sampled where some fish have been seen during low flows in a reach upstream of Highway 281 (where Robust Redhorse were found spawning in the spring of 2012). Additionally, we chose to sample at six sites (sites labeled with M’s and H’s; Table 13). These additional sites were chosen using the 1:100,000 NHD hydroline. We plotted each spawning site and created a random start point downstream of each site. Using a random number generator, we chose the starting point of 600m Page 47
Broad River Robust Redhorse reintroduction status downstream of the spawning locality. We then plotted one site every 1000m downstream of each starting point. We also selected to sample each tributary from Highway 281 upstream to the North Fork that appeared on the 1:100,000 NHD hydroline (sites labeled with T’s; Table 13). Because of limited use at the Hudson River site in the spring of 2011, we focused sampling in the vicinity and downstream of the North Fork and the Broad River spawning sites. In addition to daytime sampling at these sites, we also conducted nighttime sampling at a portion of the sites. Table 13. Juvenile sampling sites chosen for 2011. Last column represents young-‐of-‐year (YOY) Jumprocks (Moxostoma sp. and Moxostoma rupiscartes), Spotted Suckers (Minytrema melanops), and Notchlip Redhorse (Moxostoma collapsum) only. Numbers represent captures in the Day sample / Night sample. 1 Locale North Fork Broad River at Highway 145 Site ID Day sample 8/30/2011 Night Latitude, sample Longitude 8/30/2011 34.29094, -‐83.17673 YOY Suckers Captured Jumprock 2 / 1 Notchlip 0 / 2 8/18/2011 34.26729, -‐83.17421 Jumprock 12 / 0 Spotted 1 / 0 Notchlip 0 / 3 34.24726, -‐83.17319 Jumprock 9 / na Spotted 3 / na Notchlip 10 / na 3 Middle Fork upstream of Highway 29 4 Middle Fork at Highway 29 8/18/2011 8/30/2011 (numbers combined) 8/31/2011 5 Broad River at Highway 281 8/31/2011 8/31/2011 34.18190, -‐83.14680 Jumprock 10 / 0 Spotted 2 / 1 Notchlip 9 / 16 6 Broad River at mouth of Vineyard Creek N/A 6/30/2011 34.12606, -‐83.05048 Notchlip na / 4 7 Broad River upstream of Highway 281 10/7/2011 N/A 34.18753, -‐83.15068 Jumprock 8 / na Spotted 9 / na Notchlip 5 / na 8 Broad River within 1 km downstream of downstream spawning site North Fork within 1 km downstream of spawning site. 10/8/2011 N/A 34.26482, -‐83.17526 Jumprock 1 / na Spotted 2 / na Notchlip 2 / na 10/30/2011 N/A 34.28900, -‐83.17634 Spotted 3 / na M01 10/30/2011 N/A 34.28825, -‐83.17835 Spotted 3 / na 9 10 Broad River immediately downstream its junction with the North Fork. N/A Page 48
Broad River Robust Redhorse reintroduction status Site ID T01 Day sample 10/30/2011 Night sample N/A Latitude, Longitude 34.28765, -‐83.17771 YOY Suckers Captured Jumprock 1 / na Spotted 14 / na T03 10/30/2011 N/A 34.27479, -‐83.17676 Not sampled M05 10/30/2011 N/A 34.26942, -‐83.17730 Jumprock 1 / na Spotted 5 / na Notchlip 4 / na M06 10/8/2011 N/A 34.26203, -‐83.17513 Spotted 5 / na Notchlip 3 / na 15 Broad River, approx. M08 0.71 river miles upstream of Highway 29. 10/8/2011 N/A 34.25480, -‐83.17210 Jumprock 4 / na Spotted 9 / na Notchlip 1 / na 16 Tributary to the Broad River, approx. 0.18 river miles upstream of Highway 29. 17 Tributary to Broad River approx. 250 m downstream of Highway 29. 18 Hudson River at Highway 29. T06 10/8/2011 N/A 34.24796, -‐83.17718 Not sampled T07 10/8/2011 N/A 34.24741, -‐83.17064 No YOY H01 10/7/2011 N/A 34.23975, -‐83.17907 Jumprock 1 / na Spotted 11 / na Notchlip 3 / na Totals Locale 11 Middle Fork upstream of its junction with the North Fork. 12 Tributary to Broad River, approx. 0.38 river miles downstream of Bonds Bridge Road. 13 Broad River, approx. 0.66 river miles downstream of Bonds Bridge Road. 14 Broad River, approx. 1.34 river miles upstream of Highway 29 Jumprock 49 / 1 Spotted 70 / 1 Notchlip 37 / 25 Sampling Methods. At each site sampled, we assessed habitat available for sampling (Figure 25). We sampled each patch using a method most appropriate to the structure, velocity, depth, and bottom substrate (Table 14). At each patch we collected measurements of depth, velocity category (slow to none or not-‐slow), substrate, potential cover (large woody material, bedrock), specific habitat type (pool, backwater, riffle, run). If an identified site did not contain a specific habitat type (i.e. pool, backwater, riffle, run), the next available patch of that type downstream was sampled as an Page 49
Broad River Robust Redhorse reintroduction status “associated” patch. We identified all Moxostoma and Minytrema. We kept all Moxostoma spp. under 150 mm or any fish with questionable IDs. Some Minytrema under 200 mm were kept for vouchers, but some were released if the species was abundant at a site. Figure 25. Conceptual diagram of a sampling site with heterogeneous habitat and sampling patches (shown as red squares. Table 14. Example of juvenile sampling procedures dependent of the conditions at a specific patch. Habitat patch type Typical sampling procedures No flow, sand/sediment bottom Seine hauls (either upstream or downstream) No-‐little flow; boulder/bedrock, gravel bottom Seining, dipnetting along with backpack electrofishing Little-‐high flow; sand/sediment bottom Seining along with backpack electrofishing Little-‐high flow; boulder/bedrock, gravel bottom Kick-‐seining with backpack electrofishing Areas with large woody materials, root masses (obstructing objects in the water column) Backpack electrofishing / dipnetting Page 50
Broad River Robust Redhorse reintroduction status Figure 26. Locations of spawning sites for Robust Redhorse (Moxostoma robustum; yellow indicators), and juvenile sampling sites in 2009 within the Broad River, Georgia watershed. Red circles indicate locations where young-‐of-‐year suckers were captured and white squares indicate no young-‐of year suckers captured. Juvenile Sampling Summary For a detailed summary of site-‐specific information see Appendix 3. In 2009, we sampled 21 sites looking for juvenile suckers (Figure 26). At 12 sites, we collected at least one species of young-‐of-‐
year sucker (either jumprocks, Spotted Suckers, or Notchlip Redhorse). At nine sites no young-‐of-‐
year suckers (YOY) were captured. All sites where no YOY suckers occurred were located downstream of Highway 281, therefore efforts were focused upstream of Highway 281 for the 2011 sampling season. In 2011, we sampled 15 sites most of which occurred upstream of Highway 281 and focused in the areas around the two main spawning shoals earlier in the spring (Figure 27). We captured YOY suckers at all sites except one. Page 51
Broad River Robust Redhorse reintroduction status Figure 27. Locations of spawning sites for Robust Redhorse (Moxostoma robustum; yellow indicators) and juvenile sampling locations in 2011 within the Broad River, Georgia watershed. Red circles indicate locations where young-‐of-‐year suckers were captured and white squares indicate no young-‐of year suckers captured. No YOY Robust Redhorse were captured in any juvenile sampling effort. Although adult Spotted Suckers, jumprocks, and Notchlip Suckers were captured, no adult Robust Redhorse were collected in these efforts either. In 2009 we collected 14 YOY jumprocks, 32 YOY Spotted Sucker, and 8 YOY Notchlip Redhorse. In 2011, we collected 50 YOY jumprocks, 68 YOY Spotted Suckers, and 62 YOY Notchlip Redhorse. Our 2009 captures included jumprocks ranging from 52-‐360 mm SL (N: 14; mean: 108.21 mm; SE: 22.45), Notchlip Redhorse ranging from 65 – 340 mm SL (N: 47; mean: 196.75 mm; SE: 12.23) and Spotted Suckers ranging from 42 – 230 mm SL (N: 58; mean: 77.17; SE: 4.31). Each individual was not measured in 2011. In general, most YOY Jumprocks occurred in riffle areas in faster water, with bedrock and gravel substrates than the other YOY suckers we captured. These individuals were typically captured using kick-‐sets, where a seine was placed downstream of a riffle and substrate was disturbed and fish were dislodged downstream in the net. Commonly Page 52
Broad River Robust Redhorse reintroduction status electrofishing was not used during this method. Spotted Sucker and Notchlip Redhorse were captured in a variety of bed substrate types, but were most commonly found in association of large woody material or other structure. Typically these habitats were sampled with a backpack electrofisher, a downstream block-‐seine and a dip-‐netter. In many situations, these fish were within the large woody material and the dipnet was required along with occasional hand-‐captures. Population Recaptured Robust Redhorse During the restoration efforts for Robust Redhorse, over 30,000 Robust Redhorse were captively propagated and stocked at various locations within the Broad River system (Table 15; Appendix 1). The majority of Robust Redhorse stocked (27,933) were Phase I fish stocked in 1997 and 1998. Phase I fish were created through the capture of broodstock from the Oconee River in the spring, kept at a fish hatchery, and stocked in the fall of the same year, commonly referred to as Age 0 fish. Phase II fish (fish kept at the hatchery and stocked in the fall of the second year as Age 1 fish. Age 1 fish were stocked in 1996 and 1998. Phase III fish (fish kept at the hatchery through their second winter, Age 2 fish) were only stocked in 1995. Table 15. The number of Robust Redhorse within each Phase (Age) group stocked within the Broad River system. Years and totals within each Age group are shown in parentheses. Year Class (Stocking Year) Age of Stocked Fish Phase I total Total number within each Age Stocked 27933 1997 (1997) (25207) 1998 (1998) (2726) Phase II total 5265 1995 (1996) (1424) 1997 (1998) (3841) Phase III total Total 545 1993 (1995) (545) 33743 Since their original stocking, we know of 242 Robust Redhorse captured in the Broad River system, including Clark’s Hill Reservoir. This number does not include some fish captured within several Page 53
Broad River Robust Redhorse reintroduction status months of stocking to assess movements of recently stocked fish and possibly some other individuals captured by the Georgia Cooperative Fish and Wildlife Research Unit for experimental purposes. Most of these recaptures likely resulted in mortalities (N=154) caused by gill net sampling to assess operations at Russell dam. The remaining 88 fish where captured using boat electrofishing or other electrofishing methods and were either released or have an unknown disposition. For 155 of these individuals year class was either not determined or the fish was not checked for a coded wire tag. Table 16. Number of Robust Redhorse stocked by year class and known numbers of each year class captured. Year Class Number Stocked 1993 545 1995 1424 1997 29048 1998 2726 Total 33743 Phase stocked comments All stocked as Phase III individuals in 1995 All stocked as Phase II individuals in 1996 25207 stocked as Phase I in 1997, 3841 stocked as Phase II in 1998. All stocked as Phase I in 1998 No Tag Detected or Tag Not Checked Total (Percent) of Each Year Class Recaptured 0 (0) 6 (0.42%) 80 (0.28%) 1 (0.04%) 155 242 Of the 20 fish captured during the current study, we did not find evidence of coded wire tags on 5 individuals. During a study conducted in the Ocmulgee, 30 fish that previously received coded wire tags were checked at the hatchery prior to receiving transmitters and 2 individuals appeared to not have a coded wire tag when checked (Freeman and Straight 2004). In another Robust Redhorse study ten fish were captured in the Wateree River in 2009 (all fish at this time were presumed to be hatchery-‐reared individuals). In two of these ten fish, no coded wire tag was found (Dave Coughlin, RRCC 2009). These examples indicate that the absence of a coded wire tag as many as 20% of fish that should have coded wire-‐tags are missing tags (operator error in injection, expulsion of tag) or tag readers or operators are not locating tags that exist. Some studies show variability in coded wire tag retention (87-‐99%) and this could account for some of these “untagged” fish (Elrod and Schneider 1986; Hand et al. 2010). Retention rates also appear to vary based on tag location (Pitman and Isaac 1995; Isley and Fontenot 2000; Buckmeier 2001). Although we could only find Page 54
Broad River Robust Redhorse reintroduction status limited documentation on coded wire tag migration within the body, the location of tags in this study and on fish brought to the Georgia Museum of Natural History indicate that coded wire tags likely do migrate (Waters 1997). Basin and Rearing Comparisons Using data available from the RRCC researchers, we were able to compare sizes (total length in mm) and weight (g) of captured Robust Redhorse throughout its range (Figures 28 to Figure 34). Each capture was labeled with the river system it was captured from including the Broad River of Georgia (Broad), Savannah River, Ogeechee, Ocmulgee, Oconee, and Pee Dee. The Broad River fish were separated from the Savannah because of their difference in origin. Rearing groups included fish that are known or presumed to be hatchery-‐reared individuals and fish that were presumed to be wild-‐reared individuals, see below. We used a Bartlett’s test among systems and among rearing groups to test for homogeneity of variances. These results showed nonhomogeneous variances among systems for total length (K2 = 282.03, df = 5, p < 0.001) and weight (K2 = 181.35, df = 6, p < 0.001). Additionally this analysis showed nonhomogeneous variances among rearing-‐groups for total length (K2 = 250.46, df = 2, p < 0.001) and weight (K2 = 14.15, df = 2, p-‐value = 0.001). Using a Kruskal-‐Wallis nonparametric test in R (kruskal.test), we tested differences in length and weight among river systems, and differences in length and weight among wild-‐reared and hatchery-‐reared individuals (Sokal and Rohlf 1995). When differences between systems or rearing occurred we used a post hoc test for multiple comparisons between systems or rearing groups (function kruskalmc in R package pgirmess; Siegel and Castellan 1988). In these analyses, an alpha of 0.05 was considered significant. Data presented represent the mean ± standard error. This dataset include fish presumed or known to be hatchery-‐reared including 243 individuals from the Broad River, Georgia; 100 from the Ocmulgee River and 82 from the Ogeechee River system. Systems with mostly or all wild-‐reared individuals came from the Oconee (N = 1126; some of these individuals are hatchery-‐reared), the Pee Dee River system (N = 96; some of these records may include recaptured individuals), and Savannah (N = 426; some of these records may also include recaptures). Sample sizes in the specific analyses below are noted, because some measurements were not taken on captured fish. Page 55
Broad River Robust Redhorse reintroduction status Figure 28. Total length categories (mm) for Robust Redhorse captured within the different river systems within its range. Top includes the Oconee River fish captured; bottom excludes Oconee River fish to show details between the other river systems. Broad River, Ocmulgee, and Ogeechee consist all or primarily of stocked individuals. Differences in Systems When comparing between systems, we found differences in the total length between systems (Kruskal-‐Wallis !2 = 834.05, df = 5, p < 0.001). The multiple comparison tests revealed 12 significant pairwise comparisons (Table 17; Figure 28). The only non-‐significant pairwise comparisons were Broad-‐Ogeechee, Ocmulgee-‐Ogeechee, and Oconee-‐Pee Dee. Two systems with a majority wild reared fish, Oconee and Pee Dee, did not differ in the total length (mm) of captured Page 56
Broad River Robust Redhorse reintroduction status fish. The Broad and Ogeechee showed no differences and Ocmulgee showed no difference with fish from the Ogeechee. The Savannah River fish differed from all other systems in total length. Table 17. Mean and standard deviation of A. total length (mm) and B. weight (g) by river system for Robust Redhorse captured. A. Length Total Length (mm) System* N Mean ± SE A
Ocmulgee 100 407.26 ± 11.02 AB
Ogeechee 82 463.67 ± 5.44 B
Broad 243 509.86 ± 5.14 D
Savannah 426 601.25 ± 2.49 C
Oconee 1126 630.75 ± 1.40 C
PeeDee 96 635.76 ± 7.21 B. Weight Weight (g) System* N Mean ± SE A
Ogeechee 82 1412.94 ± 49.13 A
Ocmulgee 74 1832.11 ± 143.73 A
Broad 243 1917.37 ± 51.51 B
Savannah 426 3420.22 ± 43.11 C
Oconee 1126 4024.54 ± 25.30 C
PeeDee 96 4138.54 ± 151.07 * Different letters behind river systems within total length and within weight denote systems with significantly different means. There were also differences in mean weight between systems (Kruskal-‐Wallis !2 = 791.26, df = 5, p < 0.001; Table 17; Figure 29). Total weight of fish between river systems show some similarity to total length with mean weights of Savannah fish being different than those from other systems and no differences between Oconee and Pee Dee River fish. However, higher variability of weight may have masked any differences in weight between the Ogeechee, Ocmulgee, and Broad River fish. All three systems originate from hatchery stock, and most have relatively young populations. Page 57
Broad River Robust Redhorse reintroduction status Figure 29. Weight categories (g) for Robust Redhorse captured within the different river systems within its range. Top includes the Oconee River fish captured; bottom excludes Oconee River fish to show details between the other river systems. Broad River, Ocmulgee, and Ogeechee consist all or primarily of stocked individuals. To assess the population of fish in the Broad River system, we also compared the lengths and weights of fish captured in the Broad River to other fish identified as hatchery-‐reared fish and wild fish. We classified all Ogeechee, all Ocmulgee, and some fish stocked and identified via coded wire tags in the Oconee as Hatchery fish. Mean total lengths were different between rearing classes (Kruskal-‐Wallis !2 = 757.52, df = 2, p < 0.001). The multiple comparison tests revealed differences between all pairwise comparisons (Table 18; Figure 30). The mean total length of fish identified as wild-‐reared fish were longer than fish captured in the Broad River system and the mean total Page 58
Broad River Robust Redhorse reintroduction status length of hatchery fish from other systems was lower than those captured in the Broad. This result is not surprising given that the Broad River fish are the oldest of the hatchery-‐reared fish. Presumably the wild fish should have even older age classes within their population structure, given a maximum life span of around 26 years. Figure 30. Total length categories (mm) of Robust Redhorse from the Broad River, other hatchery-‐
reared (Ogeechee, Ocmulgee) and wild-‐reared individuals. Table 18. Mean and standard deviation of A. total length (mm) and B. weight (g) by rearing group (Broad River, other Hatchery-‐reared, or Wild) for Robust Redhorse captured. A. Length Rearing* Hatchery Broad Wild B. Weight N Total Length (mm) Mean ± SE 420 20 1639 470.55 ± 4.49 586.45 ± 9.12 623.03 ± 1.27 Weight (g) Rearing* N Mean ± SE Hatchery 394 1720.81 ± 41.97 Broad 20 2844.6 ± 145.32 Wild 1639 3885.44 ± 23.60 *Post hoc pair-‐wise comparisons showed significant differences between all pairs. Page 59
Broad River Robust Redhorse reintroduction status Mean weights of the Broad, other hatchery-‐reared, and wild-‐reared fish were also different (Kruskal-‐Wallis !2 = 665.43, df = 2, p < 0.001). There were differences between all pairwise comparisons of mean weights as well (Table 18; Figure 31). These results are similar to the total length results, showing fish from the Broad River having intermediate weights between hatchery fish and wild fish. Figure 31. Weight categories (g) of Robust Redhorse from the Broad River, other hatchery-‐reared fish (Ogeechee, Ocmulgee) and wild-‐reared individuals. For 1610 individuals, we had both weight and total length. We plotted length-‐ weights for these individuals comparing our study fish (Broad) to other hatchery-‐reared fish and to wild fish (Broad vs. Hatchery: Figure 32; Broad vs. Wild: Figure 33). Visually the Broad River fish used in this study visually fell within the range of the hatchery-‐reared fish, except with the longest individuals. We compared the ratio of length to weight between rearing groups and found a difference between groups (Kruskal-‐Wallis !2 = 74.75, df = 2, p < 0.001). The multiple comparison tests revealed differences in the length-‐weight ratio between our study fish (Broad) and wild-‐reared fish and a difference between other hatchery-‐reared fish and wild-‐reared fish. These results showed no difference between the mean length-‐weight ratio of our Broad River study fish and the other hatchery-‐reared fish. Wild-‐reared fish had the smallest ratio (0.17 ± 0.001), next highest was the Broad River study fish (0.21 ± 0.01) and then the other hatchery –reared fish (0.24 ± 0.01). These Page 60
Broad River Robust Redhorse reintroduction status differences could be resulting from differences in age of the population being measured. The wild-‐
reared population contains presumably some of the oldest fish and if this ratio decreases as fish age this could explain the differences between the rearing groups. Using known age fish this ratio appears to decrease as the fish ages (Figures Figure 34 and Figure 35). Figure 32. Weight-‐total length relationship of Broad River Robust Redhorse (red squares, black line) used in this study compared to other Hatchery-‐reared Robust Redhorse (blue diamonds, blue line). Figure 33. Weight-‐total length relationship of Broad River Robust Redhorse (red squares, black line) used in this study compared to Wild-‐reared Robust Redhorse (green triangles, green line). Page 61
Broad River Robust Redhorse reintroduction status Known Age Fish Using hatchery-‐reared individuals collected at various times we plotted the total length (mm) and weight (g) for known-‐aged fish (Figure 34). These fish were collected and checked for coded wire tags. Tag location allowed aging of an individual at the time of capture. These fish showed a slowing in the rate of growth of both total length (mm) and weight (g). This graph also illustrates the variability in weight. Fish that spent numerous years within the hatchery caused some of this variability. Other sources of variability include fish condition and time of year the capture occurred. Adult fish during the reproductive season should show increased average weight. During any season fish may have variability in weight dependent in seasonal and yearly fluctuations in resources and individual feeding abilities and other behaviors. Figure 34. Relationship of weight (g; red squares) and total length (mm; blue diamonds) for known age fish. Age 1 fish were measured upon removal from hatchery sources. The two points marked with asterisks were from four fish that spent three to six years at the hatchery prior to stocking. Page 62
Broad River Robust Redhorse reintroduction status Figure 35. Ratio of total length to weight, by known age of coded wire tagged Robust Redhorse. Age can reliably be estimated for many species of fish using scale annuli. However, estimating age with scale annuli for catostomids have commonly been determined to underestimate age (Beamish 1973; Beamish and McFarlane 1983; Scoppettone 1988; Jenkins 1999; Sylvester and Berry 2006; Quist et al. 2007). Aging Robust Redhorse using scale annuli for older individuals (especially those 10 years or older) appear to be inaccurate and underestimate the age of the individual (Jenkins et al., unpublished manuscript). This inaccuracy is also seen in using scales to age Sicklefin Redhorse, using scales to age individuals over seven years appeared underestimate age by 1-‐8 years (Jenkins 1999). It is unknown how reliable aging is for Robust Redhorse between 5 and 10 years, but there may be some inaccuracies in aging even within this age group. Scoppettone (1998) suggests that scale aging becomes unreliable at around the time of maturation; this general timing seems to be true of other catostomid species (Reid 2007). Until ages are validated and the some known relationship between age using scales and known age is created, information used from this technique to manage Robust Redhorse should be taken with extreme caution (Beamish and McFarlane 1983). Because of the need to estimate age of fish within the Broad River system to assess the likelihood of recruitment, we used logistic regression to model the effects of total length and weight on the odds of a fish being less than 12 years old. We conducted a Bayesian analysis and used uninformative priors with normal distributions for the intercept and length coefficient. For this Page 63
Broad River Robust Redhorse reintroduction status analysis we standardized lengths by subtracting the grand mean and dividing by the standard deviation. Data from 84 individuals with known ages (classified as either less than or older than 12 years old), total lengths (mm), drove 200,000 Markov chain Monte Carlo (MCMC) iterations, after a 100,000 burn-‐in, to estimate the log odds of being older or younger than 12 years old. We then converted these odds to the probability that an individual was less than 12 years old (predicted odds / 1+predicted odds). The MCMC analysis resulted in the model: log(p/1-‐p) = 3.757 + -‐4.583*length. The probability that a Robust Redhorse is less than 12 years old is negatively associated with total length (Figure 36). To help show the probability of age for different size fish, we present a probability curve with total lengths ranging from 450-‐700 mm (Figure 36; Appendix 4). The probability of individual fish 530 mm or shorter being less than 12 years old was greater than 0.75. Individuals that were 596 mm or more in length had a probability of 0.25 or less of being less than 12 years old. The probabilities for individuals between 530 and 596 range between 0.75 and 0.25 (Appendix 4). Given these probabilities, we can look at accuracy of this curve with fish captured for this study (Table 19). At least one individual with a mean probability of being less than 12 years old of 0.77 was known to be 13 at the time of capture (and time of measurement). Figure 36. Mean probability and credible interval that an individual Robust Redhorse from 450 – 700 mm total length is less than 12 years old based on a logistic regression using 84 known age individuals. Page 64
Broad River Robust Redhorse reintroduction status Table 19. Mean probability of each Robust Redhorse captured during this study of being less than 12 years old, based on a logistic regression of 84 known age individuals. Known age reported from location of coded wire tag detected. NA indicates an absence of coded wire tag. ID 53959 53965 53955 53958 53962 53975 53972 53971 53966 53956 53961 53951 53964 53949 53977 53974 53963 53948 53967 53953 Known Age NA 13 NA 14 13 NA 14 14 14 NA 13 14 13 13 14 14 NA 13 14 14 TL 535 541 544 555 563 563 564 564 566 566 570 579 590 608 610 615 620 624 662 690 Mean probability of being < 12 (95% credible interval) 0.8439 (0.6919-‐0.9518) 0.7792 (0.6035-‐0.915) 0.7397 (0.5526-‐0.8902) 0.5603 (0.3353-‐0.7638) 0.4173 (0.1884-‐0.6542) 0.4173 (0.1884-‐0.6542) 0.4002 (0.1734-‐0.6406) 0.4002 (0.1734-‐0.6406) 0.367 (0.1453-‐0.6121) 0.367 (0.1453-‐0.6121) 0.3053 (0.0994-‐0.5564) 0.194 (0.0385-‐0.4377) 0.1069 (0.0111-‐0.3119) 0.0394 (0.0014-‐0.1642) 0.0353 (0.0011-‐0.1522) 0.0269 (0.0006-‐0.1256) 0.0205 (0.0003-‐0.1029) 0.0166 (0.0002-‐0.0875) 0.0024 (0-‐0.0177) 0.0007 (0-‐0.0053) Adult spawning population size Although we did not recapture enough Robust Redhorse within the system to use for a population analysis, we attempted to estimate the number of fish participating in spawning throughout the spawning period. Assuming limited movement between sites and patches when counts took place, we estimated a range of 86-‐107 fish spawning each year and a range of 14-‐73 individuals at each site (Table 20). If individual males only remain within the spawning area for approximately 4 days as seen by Grabowski and Isley (2008) and given a 12-‐day spawning period, these numbers could be closer to 2-‐ to 3-‐times of our initial estimation. This turn-‐over in territorial males, however has not been confirmed in any other Robust Redhorse populations. Our observations of individual males (based on identifying scars, coloration and other markings) indicate males were present at an individual spawning site several days in a row. Page 65
Broad River Robust Redhorse reintroduction status We did notice variability in size of males and females within the spawning groups, with smaller males relegated to the marginal portion of the spawning group. Any individuals with reddish-‐tinge to the caudal fin were typically seen within these marginal areas. A more red coloration in the caudal fins appears to be typical of younger-‐aged individuals, with this coloration becoming more orange as individuals age. This coloration is definitely seen in individuals with breeding tubercles and participating in spawning (at least 5-‐6 years). However, loss of this coloration has not been definitively associated with a specific age (R. Jenkins, pers. comm). These red-‐finned males were noticeably smaller than the largest males holding position, but are similar in size to other smaller individuals without red fins. Table 20. Maximum number of adult Robust Redhorse (Moxostoma robustum) counted at each spawning site and the peak date of spawning for 2010, 2011, and 2012. Hudson North Fork Wagoners Broad (us 281) Total 2010 2011 2012 Max. Number Peak Day Max. Number Peak Day Max. Number Peak Day 26 31 29 NA 86 5/13-‐5/14 5/16 5/14 NA 10 24 73 NA 107 5/9/11 5/12 5/12 NA 14 NA 66 23 104 5/1 NA 5/1 5/3 Management Implications The results of this study show that Robust Redhorse stocked within the Broad River system have survived to reach spawning age and are participating in spawning. The variability of flows and flow management within the Southeast has been proven to be a challenge for conservation of sucker species (Travnichek and Maceina 1994; Cooke et al. 2005). There have been historical records of droughts in the Broad River system (Coulter 1965), which may have impeded fish movements. For long-‐lived species, foregoing or limited spawning in occasional years may not be detrimental, however in managed systems or during prolonged drought this could have a negative impact on populations. Altered flow regimes and resulting habitat changes have been cited as contributing to sucker declines (Cooke et al. 2005). Page 66
Broad River Robust Redhorse reintroduction status River / Habitat Conditions Drought conditions could also create potential problems within the spawning shoals. As water levels drop during the spawning season, the fish within the Broad River system were able to shift spawning sites into deeper areas. However, spawning lenses that became too shallow to be used for spawning began filling in with fine sediments. These fine sediments can bury or entomb eggs or larvae in the gravel matrix (Waters 1995). In spawning sites within the Broad River system, most spawning lenses remained covered in water throughout the estimated larval period of the young, but as flow over these areas decline, fine sediments fill in and oxygenation of the gravel also likely decreases (Gordon et al. 1992). Robust Redhorse found and used a variety of spawning patches within the Broad River system. All of these spawning areas are farther upstream of the Fall zone than areas used in other systems. Gravel used for spawning was deep, allowing spawning lenses to build up in areas over 0.7m above the bed. These lenses maybe artifacts of the spawning activities, but also likely provide a hydraulic gradient for keeping eggs and larval fish oxygenated and removing waste products as they remain in the gravel. Areas with gravel of insufficient depth may reduce hatching success or larval survival through improper burial or improper oxygenation. Most areas used for spawning were extensive. Within the main spawning sites in Georgia, spawning sites consisted of a single, large spawning patch. Most spawning sites in the Broad River system are in smaller rivers (some less than 30 m width), and contain two to six spawning patches used by Robust Redhorse within 200m of each other. These patches provided a variety of flows, depths, and substrates. In 2011, we estimated that the spawning area used within the Wagoner’s site was over 180 m2 of gravel. The other sites were smaller, but any one site never held fewer than 14 individuals at the peak of spawning season. All of the spawning sites were within 16 km of each other and fish were documented moving between spawning sites within the spawning season (approximately 7 km distance). The proximity of a variety of spawning options within a relatively short segment of river allows fish to adjust to changes in conditions and to choose spawning areas to potentially maximize their fitness. Altered flow regimes downstream of Thurmond Dam, may also play a role in differences in the sizes of the Savannah Robust Redhorse compared to other Wild populations (Oconee and Pee Dee). It is possible that as a result of colder flows, differences in flow regimes in the Savannah relative to other systems that Robust Redhorse within the Savannah are smaller. Alternatively, the Savannah population could be showing evidence of younger fish than those in the Oconee and Pee Dee River Page 67
Broad River Robust Redhorse reintroduction status systems, potentially indicating a healthier population structure. More research will need to be conducted on determining the age of the Savannah population relative to the Oconee and Pee Dee. Within the stocked populations, Robust Redhorse in the Broad River system (and Clark’s Hill Reservoir) were larger than some of the other hatchery-‐reared fish, but this is likely because of differences in age of the captured individuals. Another potential concern with increasing variability in weather and water temperatures, concerns high water temperatures during the period when eggs and larvae are within the gravel and for young juveniles. Walsh et al. (1998) notes that hatching success of eggs decrease as temperatures rise above 23° C and that there is an increased likelihood of deformities in larval and juvenile fish as temperatures increase above 25° C. At the main spawning site in 2012, the average temperature was above 22° C for 8 of the 10 days spawning fish were observed. Additionally 4 of the 10 days the maximum temperature was over 25° C. We have not had continuous temperatures for a specific spawning site in other years, but the combination of temperatures during the egg and larval stage could contribute to lower survival and contribute to low recruitment. Recruitment Recruitment is a primary concern for conservation of Robust Redhorse. Although we didn’t collect YOY Robust Redhorse during this study, to our knowledge no YOY suckers past the larval stage have been captured in any system where it currently occurs. Although we were able to capture YOY of other large-‐bodied suckers within the system, the lack of Robust Redhorse YOY captures indicates the likelihood of an inability to capture existing YOY Robust Redhorse. This could be caused by a limited recruitment, where survival past the larval stage is limited and YOY Robust Redhorse are truly rare within the system, inappropriate sampling techniques, or sampling of inappropriate habitat. Young-‐of-‐year Black Redhorse (Moxostoma duquesnei) were found in pools with water willow (Justicia americana; Bowman 1970). Captures of juvenile Sicklefin Redhorse (Moxostoma sp.) have been noted from reservoirs, e.g. Hiawassee Lake, along with River Redhorse (Moxostoma carinatum) and Black Redhorse (Jenkins 1999; Georgia Museum of Natural History unpublished records). Robust Redhorse is one of the longer-‐lived redhorse species, with a reproductive period starting at 5-‐6 years and possibly lasting throughout the remainder of its life (potentially 20+ years). There is no known evidence of senescence in this species. This species is long-‐lived, has late maturity, and is a periodic spawner, and fits the classification of a periodic life-‐history strategy Page 68
Broad River Robust Redhorse reintroduction status species (Winemiller and Rose (1992). According to the theory these species spread their reproductive efforts over multiple years with occasional years of good survival, but with many years where survival for each female might be close to zero. This variation in YOY survival is seen in studies of another periodic strategist, River Redhorse (COSEWIC 2006). Many sampling gears have been applied within this and other systems including seine hauls, kick-‐
seining, backpack electrofisher, boat electrofisher, light traps, hoop nets and gill nets. While conducting sampling surveys for Robust Redhorse within other systems (Ocmulgee, Oconee, Ogeechee, Pee Dee, and Savannah), over 100 Robust Redhorse between 200 and 500 mm total length have been captured. Of these the majority, 98 of 122, were greater than 400 mm. Within the Broad River system, 62 Robust Redhorse less than 500 mm TL have been collected using boat electrofisher and gill nets. Most of these individuals were captured within 2-‐6 years of their stocking years. These captures indicate that some proportion of smaller Robust Redhorse are vulnerable to boat electrofishing and gill netting. In the Broad River system we could be confident that any individual less than 500 mm length would signify recruitment (with at least a 0.90 probability). As the original stocking class ages the minimum size to indicate recruitment should also increase. Continued collections to refine the probability curves as the stocked fish age should help with verification of recruitment within the system. The occurrence of smaller breeding individuals being seen within spawning aggregations suggests that recruitment is still occurring in some systems, although recruitment may be at an extremely low rate. Although these individuals appeared smaller than other individuals within the spawning shoal, we can not verify their total length to determine if these individuals consist of wild-‐recruited individuals or just represent variability within the stocked population of individuals. Molecular Markers If no fish less than 500 mm TL within the system is captured, the use of genetic marker to positively identify recruitment within this system seems a logical alternative. Unlike existing methods of assessing recruitment, there is no possibility of tag loss with genetic markers. If molecular markers for the Oconee River genetic stock is developed and cataloged for all broodstock used in the reintroduction effort within the Broad River system, this genetic information should allow the positive identification of all natural recruitment within the system (T. Darden, pers. comm.). There is a possibility that a second generation of Robust Redhorse (first generation of wild raised Page 69
Broad River Robust Redhorse reintroduction status individuals) that are entering the spawning population. Once fish reach this size, aging by use of scales is unreliable and for smaller individuals total length is inaccurate for estimating age. Development molecular markers would allow us to confirm recruitment and also allow an assessment of which parental crosses had the highest survival and recapture within the system and within other systems where stocking has occurred. This also demonstrates the need to collect genetic samples from each individual captured to assess population information. We believe that future Robust Redhorse work should put effort into characterizing the genetic markers for all Robust Redhorse used as broodstock in Georgia. Future Work in the Broad Recruitment Sampling Research on Sicklefin Redhorse found most juvenile fish in the forebays of reservoirs or near the receiving river mouths in areas with limited current (Jenkins 1999). Sampling these types of habitats within Clark’s Hill, focusing on the area between Anthony Shoals and the Highway 79 bridge may be the most likely locality for finding juveniles or YOY. Currently, these forebays are shallow and have no to limited access via motor boat and a canoe electrofisher may be the only way to access these areas to sample. Because of questions about aging fish and coloration, we suggest that during all sampling a selection of scales should be collected. We suggest taking scales from the area 2-‐3 rows ventral of the dorsal fin. Scales in this area has been used in other redhorse aging work (Scoppettone 1998; Beckman and Hutson 2012). In the future, methods of aging with scales may become more reliable and we believe having a representative sample is important. With further study and age validation, we may be able to use scales more affectively to age Robust Redhorse. The collector should assess caudal and other fin coloration and possibly compare it to a known color standard (e.g. recording chroma and value for a select Munsell color chart; Soil Color Charts 2.5 YR, 5YR, and 7.5YR). Additionally, fin clips should be taken to allow assessment of genetic markers. Sampling spawning areas could also provide additional information. However, we suggest a sampling method that minimizes stress on individuals within the spawning shoal. Removing territorial individuals from the spawning shoal could have unintended behavioral effects. Additionally, electrofishing has been shown to increase mortality in larval fish (Muth and Ruppert 1997; Snyder 2003 and references therein). References within Snyder (2003) suggest that Page 70
Broad River Robust Redhorse reintroduction status mortalities of fish embryos can range from 5-‐97% depending on the age of the embryo, shocking duration, and field intensity. We suggest collection of individuals in early spring, prior to spawning migration, in the area of Anthony Shoals and measurements and information can be collected there without disruption of spawning, adding stress to spawning individuals, and minimizing harm to eggs and larval fish. Literature Cited Beamish, R.J. 1973. Determination of age and growth of populations of the White Sucker (Catostomus commersoni) exhibiting a wide range in size at sexual maturity. Journal of the Fisheries Research Board of Canada 30: 607–616. Beamish, R.J. and G.A. McFarlane. 1983. The forgotten requirement for age validation in fisheries biology. Transactions of the American Fisheries Society 112: 735–743. Beckman, D.W. and C.A. Hutson. 2012. Validation of aging techniques and growth of the River Redhorse, Moxostoma carinatum, in the James River, Missouri. The Southwestern Naturalist 57(3): 240-‐247. Berndt, M.P., E.T. Oaksford, M.R. Darst, and R.L. Marella. 1996. Environmental setting and factors that affect water quality in the Georgia-‐Florida Coastal Plain: U.S. Geological Survey Water-‐
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Broad River Robust Redhorse reintroduction status Favrot, S. D. 2009. Sicklefin Redhorse reproductive and habitat ecology in the upper Hiwassee River basin of the southern Appalachian Mountains. Master’s Thesis. North Carolina State University, Raleigh, North Carolina. Fisk, J.M. 2010. Reproductive Ecology and Habitat Use of the Robust Redhorse in the Pee Dee River, North Carolina and South Carolina. M.S. Thesis, North Carolina State University, Raleigh, NC. 126 pp. Freeman, B.J. and M.C. Freeman. 2001. Criteria for suitable spawning habitat for the Robust Redhorse Moxostoma robustum. Report to the U.S. Fish and Wildlife Service, Athens, Georgia. Freeman, B.J. and C.A. Straight. 2004 Tracking of Robust Redhorse (Moxostoma robustum) released on 19 March 2002 on the Ocmulgee River below Lloyd Shoals Dam. Report to National Fish and Wildlife Foundation. 33 pp. Freeman, B.J., C.A. Straight, J.R. Knight, and C.M. Storey. 2002. Evaluation of Robust Redhorse (Moxostoma robustum) introduction into the Broad River, GA spanning years 1995-‐2001. Report Submitted to Georgia Department of Natural Resources. pp. 70. Gordon, N.D., T.A. McMahon, and B.L. Finlayson. 1992. Stream hydrology: an introduction for ecologist. John Wiley & Sons Ltd., New York, NY. pp. 526. Grabowski, T.B. 2006. Reproductive ecology and seasonal migrations of Robust Redhorse (Moxostoma robustum) in the Savannah River, Georgia and South Carolina. PhD Dissertation, Clemson University, South Carolina. Grabowski, T.B. and J.J. Isely. 2006. Seasonal and diel movements and habitat use of Robust Redhorse in the Lower Savannah River, Georgia and South Carolina. Transactions of the American Fisheries Society 135: 1145-‐1155. Grabowski, T.B. and J.J. Isley. 2007. Spatial and temporal segregation of spawning habitat by catostomids in the Savannah River, Georgia and South Carolina, U.S.A. Journal of Fish Biology 70: 782-‐798. Grabowski, T.B. and J.J. Isely. 2008. Size of spawning population, residence time, and territory shifts of individuals in the spawning aggregation of a riverine catostomid. Southeastern Naturalist 7(3): 475-‐482. Hand, D.M., W.R. Brignon, D.E. Olson, and J. Rivera. 2010. Comparing two methods used to mark juvenile Chinook Salmon: Automated and manual marking. Journal of Aquaculture 72: 10-‐
17. Jackson, C.R. and S.L. Long. 2011. Evaluation of sediment particle size dynamics at gravel bars used by Robust Redhorse (Moxostoma robustum) for spawning in the upper Savannah River. Report prepared for United States Army Corps of Engineers, Savannah District. 24pp. Jenkins, R.E., M.D. Clements, and S.C. Moore. Unpublished manuscript, 1998. Synopsis of Age, Growth, and Maturation of the Robust Redhorse Moxostoma robustum. Jenkins, R. E. 1999. Sicklefin Redhorse Moxostoma sp., undescribed species of sucker (Pisces, Catostomidae) in the upper Tennessee River drainage, North Carolina and Georgia – description, aspects of biology, habitat, distribution, and population status. Report to the U.S. Department of Interior, Fish and Wildlife Service, Asheville, North Carolina, and the North Carolina Wildlife Resources Commission, Raleigh, North Carolina. Page 72
Broad River Robust Redhorse reintroduction status Isley, J.J. and Q.C. Fontenot. 2000. Retention of coded wire tags in juvenile Shortnose Sturgeon. North American Journal of Fisheries Management 20: 1040-‐1043. Jepsen, N., A. Koed, E.B. Thorstad, and E. Baras. 2002. Surgical implantation of telemetry transmitters in ﬁsh: how much have we learned? Hydrobiologia 483: 239-‐248. Muth, R.T. and J.B. Ruppert. 1997. Effects of electrofishing fields on captive embryos and larvae of Razorback Sucker. North American Journal of Fisheries Management 17: 160-‐166 Nichols, M. 2003. Conservation strategy for Robust Redhorse (Moxostoma robustum). Report prepared for the Robust Redhorse Conservation Committee. pp. 22. Page, L.M. and C.E. Johnston. 1990. Spawning in the Creek Chubsucker, Erimyzon oblongus, with a review of spawning behavior in suckers (Catostomidae). Environmental Biology of Fishes 27: 265-‐272. Pitman, V.M. and J. Isaac Jr. 1995. Coded wire tag retention by Paddlefish at three implant sites. North American Journal of Fisheries Management 15: 878-‐880. Quist, M.C., Z.J. Jackson, M.R. Bower, and W.A. Hubert. 2007. Precision of hard structures used to estimate age of riverine catostomids and cyprinids in the upper Colorado River Basin. North American Journal of Fisheries Management 27: 643–649. Reid, Scott M. 2007. Comparison of scales, pectoral fin rays and opercles for age estimation of Ontario redhorse, Moxostoma, species. Canadian Field-‐Naturalist 121: 29–34. Robust Redhorse Conservation Committee (RRCC). 1997. Robust Redhorse Conservation Committee Annual Report. pp. 54. Robust Redhorse Conservation Committee (RRCC). 2002. Robust Redhorse Conservation Committee Policies. Adopted October 18, 2002. pp. 49. Robust Redhorse Conservation Committee (RRCC). 2009. Report of the Robust Redhorse Conservation Committee Annual Meeting. Compiled by J. Zelko. Web Wildlife Management Area, Garnett, SC. September 14 – 16, 2009. Robust Redhorse Conservation Committee (RRCC). 2011. Annual meeting of the Robust Redhorse Conservation Committee. Morrow Mountain State Park, Albemarle, North Carolina. 3-‐5 October 2011. Robust Redhorse Conservation Committee (RRCC). 2012. Annual meeting of the Robust Redhorse Conservation Committee. Morrow Mountain State Park, Albemarle, North Carolina. 9-‐10 October 2012. Scoppettone, G.G. 1988. Growth and longevity of the Cui-‐ui and longevity of other catostomids and cyprinids in western North America. Transactions of the American Fisheries Society 117:301–307. Siegel and Castellan (1988) Non Parametric Statistics for the Behavioural Sciences. MacGraw Hill Int., New York. pp 213-‐214. Slaughter, J.E. IV. 2011. Conservation and Restoration of the Robust Redhorse Moxostoma robustum in the Oconee River, Georgia. Volume 7. Report prepared for the Federal Energy Regulatory Commission by Georgia Power. pp. 20. Snyder, D.E., 2003, Electrofishing and its harmful effects on fish, Information and Technology Report USGS/BRD/ITR-‐-‐2003-‐0002: U.S. Government Printing Office, Denver, CO, 149 p. Page 73
Broad River Robust Redhorse reintroduction status Sokal, R.R., and F.J. Rohlf. 1995. Biometry: The Principles and Practice of Statistics in Biological Research. 3rd edition. W.H. Freeman, New York. Sylvester R.M., and C.R. Berry, Jr. 2006. Comparison of White Sucker age estimates from sales, pectoral fi n rays, and otoliths. North American Journal of Fisheries Management 26:24–31. Travnichek, V. H., and M. J. Maceina. 1994. Comparison of flow regulation effects on fish assemblages in shallow and deep water habitats in the Tallapoosa River, Alabama. Journal of Freshwater Ecology 9: 207 -‐ 216. Walsh, S.J., D.C. Haney, C.M. Timmerman, R.M. Dorazio. 1998. Physiological tolerances of juvenile Robust Redhorse, Moxostoma robustum: conservation implications for an imperiled species. Environmental Biology of Fishes 51: 429–444. Waters, T.F. 1995. Sediments in streams: Sources, biological effects and control. Monograph 7. American Fisheries Society, Bethesda, Mayland. Waters, D. S., C. S. Guy, and C. P. Clouse. 1997. Relative position of coded wire tags in Paddleﬁsh rostrums. Transactions of the American Fisheries Society 126: 338–342. Winemiller, K.O. and K.A. Rose. 1992. Patterns of life-‐history diversification in North American fishes: implications for population regulation. Canadian Journal of Fisheries and Aquatic Sciences 49:2196-‐2218. Winter, J. D. 1996. Advances in Underwater Biotelemetry. In B. R. Murphy and D. W. Willis, editors. Fisheries Techniques, 2nd edition. American Fisheries Society, Bethesda, Maryland. Pages 555-‐590. Wirgin, I., T. Opperman, and J. Stabile. 2001. Genetic divergence of Robust Redhorse, Moxostoma robustum (Cypriniformes: Catostomidae), from the Oconee River and the Savannah River based on mitochondrial DNA control region sequences. Copeia: 526-‐530. Page 74
Broad River Robust Redhorse reintroduction status Appendices Appendix 1 Appendix 1. Robust Redhorse stocking sites, dates, and total individuals released into the Broad River Watershed from 1995-‐1998. Date Stocked 3/9/95 3/9/95 8/9/95 Year Class 1993 1993 1993 Number Stocked 250 195 100 River Locale South Fork Broad River Highway 22 North Fork Broad River Highway 51 South Fork Broad River Watson Mill State Park Age Phase III Phase III Phase III 11/21/96 11/21/96 11/21/96 1995 1995 1995 1995 TOTAL Hudson River Highway 29 South Fork Broad River Watson Mill State Park North Fork Broad River Highway 51 545 1124 150 150 Phase II Phase II Phase II 10/10/97 11/10/97 11/19/97 11/20/97 11/20/97 11/20/97 11/20/97 11/21/97 11/24/97 11/25/97 11/25/97 11/25/97 1997 1997 1997 1997 1997 1997 1997 1997 1997 1997 1997 1997 Hannah Creek North Fork Broad River North Fork Broad River Hannah Creek Hudson River Hudson River North Fork Broad River North Fork Broad River Middle Fork River Hannah Creek Hudson River Hudson River 1996 TOTAL Hannah Creek Church Rd Highway 145 Highway 145 Hannah Creek Church Rd Highway 106 Highway 29 Highway 51 Highway 145 Atkinson Road Hannah Creek Church Rd Highway 106 Highway 29 1424 300 1800 2200 300 1300 2731 926 5900 3000 750 3000 3000 Phase I Phase I Phase I Phase I Phase I Phase I Phase I Phase I Phase I Phase I Phase I Phase I 11/4/98 11/10/98 11/18/98 11/18/98 12/4/98 12/4/98 1998 1997 1997 1997 1998 1998 Hudson River Hudson River Hudson River North Fork Broad River Hannah Creek North Fork Broad River 1997 TOTAL 25207 2119 741 2479 621 361 246 Phase I Phase II Phase II Phase II Phase I Phase I 1998 TOTAL 6567 TOTAL STOCKED 33743 Highway 106 Highway 106 Highway 106 Highway 51 Hannah Creek Church Rd Highway 145 Page 75
Broad River Robust Redhorse reintroduction status Appendix 2 Appendix 2. All of the known captures of Robust Redhorse within the Broad River system since their initial stocking in 1995. Record Num. 1 Location Clark's Hill Reservoir Year Class Known Age Total Length (mm) Weight (g) Sex Latitude Longitude Capture Date NA NA 1999 NA NA 402 NA NA 2 Clark's Hill Reservoir 34.000818 -‐82.570847 2/1/1999 1995 4 404 878 NA 3 Clark's Hill Reservoir 33.977935 -‐82.576977 2/18/1999 1995 4 407 869 NA 4 Clark's Hill Reservoir 33.977935 -‐82.576977 2/18/1999 1995 4 420 908 NA Broad River at 33.983676 Anthony Shoals -‐82.645992 3/12/1999 1995 4 NA 1050 NA 5 6 Clark's Hill Reservoir 34.000818 -‐82.570847 4/5/1999 1997 2 NA 350 NA 7 Clark's Hill Reservoir 34.000818 -‐82.570847 4/5/1999 1995 2 422 1044 NA 8 Clark's Hill Reservoir 34.000818 -‐82.570847 4/5/1999 1997 2 220 117 NA 9 Clark's Hill Reservoir 34.020806 -‐82.597041 5/10/1999 1995 4 450 1450 NA 10 Clark's Hill Reservoir 34.000818 -‐82.570847 6/15/1999 1997 2 233 139 NA 11 Clark's Hill Reservoir 34.000818 -‐82.570847 6/15/1999 1997 2 324 391 NA 12 Clark's Hill Reservoir 34.002508 -‐82.582514 6/24/1999 1997 2 352 540 NA 13 Clark's Hill Reservoir 34.006155 -‐82.566474 8/17/1999 1997 2 353 650 NA 14 Clark's Hill Reservoir 34.006155 -‐82.566474 8/17/1999 1997 2 373 575 NA 15 Clark's Hill Reservoir 34.006155 -‐82.566474 8/17/1999 1997 2 372 700 NA 16 Clark's Hill Reservoir 34.006155 -‐82.566474 8/17/1999 1997 2 387 750 NA 17 Clark's Hill Reservoir 34.006155 -‐82.566474 9/22/1999 1997 2 317 425 NA 18 Clark's Hill Reservoir 34.005617 -‐82.569081 9/22/1999 1997 2 386 675 NA 19 Clark's Hill Reservoir 34.005617 -‐82.569081 9/22/1999 1997 2 361 600 NA Page 76
Broad River Robust Redhorse reintroduction status Record Num. 20 Location Clark's Hill Reservoir Year Class Known Age Total Length (mm) Weight (g) Sex Latitude Longitude Capture Date 34.005617 -‐82.569081 9/22/1999 1997 2 368 600 NA 21 Clark's Hill Reservoir 33.977935 -‐82.576977 10/19/1999 1997 2 386 750 NA 22 Clark's Hill Reservoir 33.977935 -‐82.576977 10/19/1999 1997 2 391 750 NA 23 Clark's Hill Reservoir 33.977935 -‐82.576977 10/19/1999 1997 2 349 500 NA 24 Clark's Hill Reservoir 33.977935 -‐82.576977 10/19/1999 1997 2 401 875 NA 25 Clark's Hill Reservoir 33.977935 -‐82.576977 10/19/1999 1997 2 354 525 NA 26 Clark's Hill Reservoir 33.977935 -‐82.576977 10/19/1999 1997 2 393 825 NA 27 Clark's Hill Reservoir 33.929224 -‐82.520808 11/10/1999 1997 2 387 657 NA 28 Clark's Hill Reservoir 33.929224 -‐82.520808 11/10/1999 1997 2 405 750 NA 29 Clark's Hill Reservoir 33.929224 -‐82.520808 11/10/1999 1997 2 385 690 NA 30 Clark's Hill Reservoir 33.914371 -‐82.553383 11/10/1999 1997 2 401 755 NA 31 Clark's Hill Reservoir 33.950342 -‐82.595090 11/10/1999 1997 2 377 635 NA 32 Clark's Hill Reservoir 33.990051 -‐82.582148 11/10/1999 1997 2 390 780 NA 33 Clark's Hill Reservoir 33.827087 -‐82.413299 11/11/1999 1997 2 419 958 NA 34 Clark's Hill Reservoir 33.827087 -‐82.413299 11/11/1999 1997 2 415 905 NA 35 Clark's Hill Reservoir 33.865153 -‐82.350436 12/8/1999 1997 2 NA 750 NA 36 Clark's Hill Reservoir 33.777798 -‐82.217407 12/8/1999 1997 2 NA 700 NA 37 Broad River at 33.983676 Anthony Shoals -‐82.645992 5/3/2000 1997 3 442 NA NA 38 Broad River at 33.983676 Anthony Shoals -‐82.645992 5/3/2000 1997 3 386 NA NA 39 Broad River at 33.983676 Anthony Shoals -‐82.645992 5/3/2000 1997 3 403 NA NA Page 77
Broad River Robust Redhorse reintroduction status Record Num. 40 Location Latitude Broad River at 33.983676 Anthony Shoals Longitude Capture Date Year Class Known Age Total Length (mm) Weight (g) Sex -‐82.645992 5/3/2000 1997 3 398 NA NA 41 Broad River at 33.983676 Anthony Shoals -‐82.645992 5/3/2000 1997 3 418 NA NA 42 Broad River at 33.983676 Anthony Shoals -‐82.645992 5/3/2000 1997 3 423 NA NA 43 Broad River at 33.983676 Anthony Shoals -‐82.645992 5/3/2000 1997 3 401 NA NA 44 Clark's Hill Reservoir 33.718041 -‐82.302316 11/14/2000 1997 5 430 770 NA 45 Clark's Hill Reservoir 33.950342 -‐82.595090 11/14/2000 1997 5 440 949 NA 46 Clark's Hill Reservoir 33.950342 -‐82.595090 11/14/2000 1997 5 NA 760 NA 47 Clark's Hill Reservoir 33.914371 -‐82.553383 11/15/2000 1997 5 447 1120 NA 48 Broad River at 33.983676 Anthony Shoals -‐82.645992 5/16/2001 1997 4 NA NA NA 49 Broad River at 33.983676 Anthony Shoals -‐82.645992 5/16/2001 1997 4 NA NA NA 50 Broad River at 33.983676 Anthony Shoals -‐82.645992 5/16/2001 1997 4 NA NA NA 51 Broad River at 33.983676 Anthony Shoals -‐82.645992 5/16/2001 1997 4 NA NA NA 52 North Fork Broad River 34.29148 -‐83.17745 6/18/2001 NA NA 450 NA NA 53 Broad River upstream of Highway 281 34.193569 -‐83.150286 7/12/2001 1997 4 455 NA NA 54 Broad River at 33.983676 Anthony Shoals -‐82.645992 8/12/2001 1997 4 455 1247 NA 55 Broad River at 33.983676 Anthony Shoals -‐82.645992 8/12/2001 1997 4 447 1260 NA 56 Broad River at 33.983676 Anthony Shoals -‐82.645992 8/12/2001 1997 4 461 1418 NA 57 Broad River at 33.983676 Anthony Shoals -‐82.645992 8/12/2001 1997 4 570 1814 NA 58 Hudson River 34.247383 -‐83.195247 9/6/2001 1997 4 450 1021 NA 59 Clark's Hill Reservoir NA NA 10/28/2002 1998 4 480 1692 male Page 78
Broad River Robust Redhorse reintroduction status Record Num. 60 Location Clark's Hill Reservoir Year Class Known Age Total Length (mm) Weight (g) Sex Latitude Longitude Capture Date NA NA 10/28/2002 1997 5 491 1694 female 61 Clark's Hill Reservoir NA NA 10/28/2002 1997 5 514 1850 female 62 Clark's Hill Reservoir NA NA 12/2/2002 NA NA 526 2240 female 63 Clark's Hill Reservoir 33.997883 -‐82.5716 12/17/2002 NA NA 480 1600 NA 64 Clark's Hill Reservoir 33.997883 -‐82.5716 12/17/2002 NA NA 527 1900 NA 65 Clark's Hill Reservoir 33.978533 -‐82.580983 1/8/2003 NA NA 520 2000 NA 66 Clark's Hill Reservoir 33.978533 -‐82.580983 1/15/2003 NA NA 500 1500 NA 67 Clark's Hill Reservoir 33.978533 -‐82.580983 1/15/2003 NA NA 525 2000 NA 68 Clark's Hill Reservoir 33.978533 -‐82.580983 1/15/2003 NA NA 540 2200 NA 69 Clark's Hill Reservoir 34.005283 -‐82.582233 2/11/2003 NA NA 516 1900 NA 70 Clark's Hill Reservoir 33.978533 -‐82.580983 2/12/2003 NA NA 511 1800 NA 71 Clark's Hill Reservoir 33.978533 -‐82.580983 2/12/2003 NA NA 505 1900 NA 72 Clark's Hill Reservoir 33.997883 -‐82.5716 2/19/2003 NA NA 510 1800 NA 73 Clark's Hill Reservoir 33.997883 -‐82.5716 2/19/2003 NA NA 525 1600 NA 74 Clark's Hill Reservoir 34.005283 -‐82.582233 4/29/2003 NA NA 462 1100 NA 75 Clark's Hill Reservoir 34.024333 -‐82.5934 5/10/2003 NA NA 457 1100 NA 76 Clark's Hill Reservoir 34.024333 -‐82.5934 5/10/2003 NA NA 514 1700 NA 77 Clark's Hill Reservoir 34.024333 -‐82.5934 5/10/2003 NA NA 498 1600 NA 78 Clark's Hill Reservoir 33.978533 -‐82.580983 6/18/2003 NA NA 502 1410 NA 79 Clark's Hill Reservoir 33.978533 -‐82.580983 8/5/2003 NA NA 503 1640 NA Page 79
Broad River Robust Redhorse reintroduction status Record Num. 80 Location Clark's Hill Reservoir Year Class Known Age Total Length (mm) Weight (g) Sex Latitude Longitude Capture Date 33.978533 -‐82.580983 8/5/2003 NA NA 510 1920 NA 81 Clark's Hill Reservoir 34.024333 -‐82.5934 8/12/2003 NA NA 492 1480 NA 82 Clark's Hill Reservoir 34.024333 -‐82.5934 8/12/2003 NA NA 508 1675 NA 83 Clark's Hill Reservoir 34.024333 -‐82.5934 10/19/2003 NA NA 524 1300 NA 84 Clark's Hill Reservoir 34.024333 -‐82.5934 10/19/2003 NA NA 550 2240 NA 85 Clark's Hill Reservoir 34.005283 -‐82.582233 10/19/2003 NA NA 520 1990 NA 86 Clark's Hill Reservoir 33.978533 -‐82.580983 10/20/2003 NA NA 517 2080 NA 87 Clark's Hill Reservoir 33.978533 -‐82.580983 10/20/2003 NA NA 517 1900 NA 88 Clark's Hill Reservoir 34.024333 -‐82.5934 10/21/2003 NA NA 492 1790 NA 89 Clark's Hill Reservoir 34.005283 -‐82.582233 11/5/2003 NA NA 515 2000 NA 90 Clark's Hill Reservoir 34.024333 -‐82.5934 11/16/2003 NA NA 521 2100 NA 91 Clark's Hill Reservoir 34.024333 -‐82.5934 11/16/2003 NA NA 524 2140 NA 92 Clark's Hill Reservoir 34.024333 -‐82.5934 11/16/2003 NA NA 527 2120 NA 93 Clark's Hill Reservoir 34.024333 -‐82.5934 11/16/2003 NA NA 531 2220 NA 94 Clark's Hill Reservoir 34.024333 -‐82.5934 11/17/2003 NA NA 553 2410 NA 95 Clark's Hill Reservoir 34.024333 -‐82.5934 12/8/2003 NA NA 324 364 NA 96 Clark's Hill Reservoir 34.024333 -‐82.5934 12/8/2003 NA NA 512 1810 NA 97 Clark's Hill Reservoir 34.024333 -‐82.5934 12/8/2003 NA NA 548 1900 NA 98 Clark's Hill Reservoir 34.005283 -‐82.582233 12/8/2003 NA NA 530 2040 NA 99 Clark's Hill Reservoir 34.005283 -‐82.582233 12/8/2003 NA NA 560 2003 NA Page 80
Broad River Robust Redhorse reintroduction status Record Num. 120 Location Clark's Hill Reservoir Year Class Known Age Total Length (mm) Weight (g) Sex Latitude Longitude Capture Date 33.978533 -‐82.580983 9/13/2004 NA NA 539 2200 NA 121 Clark's Hill Reservoir 33.978533 -‐82.580983 9/13/2004 NA NA 520 1990 NA 122 Clark's Hill Reservoir 33.978533 -‐82.580983 9/13/2004 NA NA 526 1638 NA 123 Clark's Hill Reservoir 33.978533 -‐82.580983 9/13/2004 NA NA 562 2350 NA 124 Clark's Hill Reservoir 34.024333 -‐82.5934 9/25/2004 NA NA 500 1700 NA 125 Clark's Hill Reservoir 34.005283 -‐82.582233 10/18/2004 NA NA 555 2500 NA 126 Clark's Hill Reservoir 34.024333 -‐82.5934 10/23/2004 NA NA 535 2100 NA 127 Clark's Hill Reservoir 34.005283 -‐82.582233 10/26/2004 NA NA NA NA NA 128 Clark's Hill Reservoir NA NA 10/27/2004 1997 7 511 1756 male 129 Clark's Hill Reservoir NA NA 10/27/2004 1997 7 514 1768 male? 130 Clark's Hill Reservoir NA NA 10/27/2004 1997 7 552 2242 male 131 Clark's Hill Reservoir 34.024333 -‐82.5934 11/8/2004 NA NA 535 1880 NA 132 Clark's Hill Reservoir 33.978533 -‐82.580983 11/9/2004 NA NA 540 2100 NA 133 Clark's Hill Reservoir 33.978533 -‐82.580983 11/9/2004 NA NA 540 2200 NA 134 Clark's Hill Reservoir 33.978533 -‐82.580983 11/9/2004 NA NA 546 2090 NA 135 Clark's Hill Reservoir 33.978533 -‐82.580983 11/9/2004 NA NA 579 2230 NA 136 Clark's Hill Reservoir NA NA 11/10/2004 1997 7 547 2238 male? 137 Clark's Hill Reservoir NA NA 11/10/2004 1997 7 525 1982 male 138 Clark's Hill Reservoir NA NA 11/10/2004 1997 7 527 2150 male 139 Clark's Hill Reservoir 34.024333 -‐82.5934 11/20/2004 NA NA 540 1950 NA Page 82
Broad River Robust Redhorse reintroduction status Record Num. 140 Location Clark's Hill Reservoir Year Class Known Age Total Length (mm) Weight (g) Sex Latitude Longitude Capture Date 34.024333 -‐82.5934 11/20/2004 NA NA 545 2210 NA 141 Clark's Hill Reservoir 33.978533 -‐82.580983 12/7/2004 NA NA 521 1800 NA 142 Clark's Hill Reservoir 33.978533 -‐82.580983 12/7/2004 NA NA 536 2000 NA 143 Clark's Hill Reservoir 33.978533 -‐82.580983 1/5/2005 NA NA 536 2510 NA 144 Clark's Hill Reservoir 33.978533 -‐82.580983 1/5/2005 NA NA 551 2600 NA 145 Clark's Hill Reservoir 33.978533 -‐82.580983 1/5/2005 NA NA 550 2000 NA 146 Clark's Hill Reservoir 34.005283 -‐82.582233 3/10/2005 NA NA 557 2600 NA 147 Clark's Hill Reservoir 34.005283 -‐82.582233 3/24/2005 NA NA 536 2200 NA 148 Clark's Hill Reservoir 33.997883 -‐82.5716 3/29/2005 NA NA 503 1200 NA 149 Clark's Hill Reservoir NA NA 4/5/2005 NA NA 536 2170 male 150 Clark's Hill Reservoir 33.978533 -‐82.580983 4/11/2005 NA NA 493 500 NA 151 Clark's Hill Reservoir 33.997883 -‐82.5716 4/11/2005 NA NA 515 1400 NA 152 Clark's Hill Reservoir 34.024333 -‐82.5934 5/13/2005 NA NA 582 2650 NA 153 Clark's Hill Reservoir 34.024333 -‐82.5934 5/13/2005 NA NA 519 1610 NA 154 Clark's Hill Reservoir 34.024333 -‐82.5934 6/14/2005 NA NA 152 45 NA 155 Clark's Hill Reservoir 34.024333 -‐82.5934 6/14/2005 NA NA 541 1900 NA 156 Clark's Hill Reservoir 34.005283 -‐82.582233 6/20/2005 NA NA 529 2050 NA 157 Clark's Hill Reservoir 34.005283 -‐82.582233 6/20/2005 NA NA 563 2300 NA 158 Clark's Hill Reservoir 34.005283 -‐82.582233 7/21/2005 NA NA 535 1850 male 159 Clark's Hill Reservoir 33.997883 -‐82.5716 9/13/2005 NA NA 606 2900 NA Page 83
Broad River Robust Redhorse reintroduction status Record Num. 180 Location Clark's Hill Reservoir Year Class Known Age Total Length (mm) Weight (g) Sex Latitude Longitude Capture Date 33.978533 -‐82.580983 9/25/2006 NA NA 575 2625 NA 181 Clark's Hill Reservoir 33.978533 -‐82.580983 11/13/2006 NA NA 585 2850 NA 182 Clark's Hill Reservoir 33.978533 -‐82.580983 2/6/2007 NA NA 453 1300 NA 183 Clark's Hill Reservoir 33.978533 -‐82.580983 8/27/2007 NA NA 545 2225 NA 184 Clark's Hill Reservoir 33.978533 -‐82.580983 10/16/2007 NA NA 574 2500 NA 185 Clark's Hill Reservoir 33.978533 -‐82.580983 10/16/2007 NA NA 615 3200 NA 186 Clark's Hill Reservoir 34.005283 -‐82.582233 11/26/2007 NA NA 603 3282 NA 187 Broad River at 33.983676 Anthony Shoals -‐82.645992 Apr-‐08 1997 12 550 1900 male 187 Broad River at 33.983676 Anthony Shoals -‐82.645992 Apr-‐08 1997 12 550 1900 male 188 Broad River at 33.983676 Anthony Shoals -‐82.645992 Apr-‐08 1997 12 625 3550 NA 189 Broad River at 33.983676 Anthony Shoals -‐82.645992 Apr-‐08 1997 12 530 1850 male 190 Broad River at 33.983676 Anthony Shoals -‐82.645992 Apr-‐08 NA NA NA NA NA 191 Broad River at 33.983676 Anthony Shoals -‐82.645992 Apr-‐08 1997 12 NA NA NA 192 Broad River at 33.983676 Anthony Shoals -‐82.645992 Apr-‐08 NA NA NA NA NA 193 Clark's Hill Reservoir 33.978533 -‐82.580983 4/7/2008 NA NA 582 2540 NA 194 Clark's Hill Reservoir 34.024333 -‐82.5934 4/8/2008 NA NA 598 2950 NA 195 Clark's Hill Reservoir 33.997883 -‐82.5716 4/14/2008 NA NA 518 1768 NA 196 Clark's Hill Reservoir 33.978533 -‐82.580983 10/13/2008 NA NA 540 2356 NA 197 Clark's Hill Reservoir 34.024333 -‐82.5934 10/21/2008 NA NA 552 2495 NA Page 85
Broad River Robust Redhorse reintroduction status Record Num. 198 Location Clark's Hill Reservoir Year Class Known Age Total Length (mm) Weight (g) Sex Latitude Longitude Capture Date 34.024333 -‐82.5934 10/21/2008 NA NA 570 2052 NA 199 Clark's Hill Reservoir 34.005283 -‐82.582233 10/21/2008 NA NA 610 3385 NA 200 Clark's Hill Reservoir 34.005283 -‐82.582233 10/26/2008 NA NA 427 1121 NA 201 Clark's Hill Reservoir 34.024333 -‐82.5934 11/11/2008 NA NA 590 2450 NA 202 Clark's Hill Reservoir 34.024333 -‐82.5934 11/22/2008 NA NA 531 2100 NA 203 Clark's Hill Reservoir 34.024333 -‐82.5934 11/22/2008 NA NA 538 2200 NA 204 Clark's Hill Reservoir 34.024333 -‐82.5934 11/22/2008 NA NA 590 3800 NA 205 Clark's Hill Reservoir 34.024333 -‐82.5934 11/22/2008 NA NA 612 3900 NA 206 Clark's Hill Reservoir 33.997883 -‐82.5716 12/8/2008 NA NA 577 2575 NA 207 Clark's Hill Reservoir 34.024333 -‐82.5934 12/9/2008 NA NA 565 2100 NA 208 Clark's Hill Reservoir 34.005283 -‐82.582233 12/9/2008 NA NA 605 3120 NA 209 Clark's Hill Reservoir 34.005283 -‐82.582233 1/7/2009 NA NA 580 2552 NA 210 Clark's Hill Reservoir 34.005283 -‐82.582233 2/23/2009 NA NA 587 2784 NA 211 Clark's Hill Reservoir 34.005283 -‐82.582233 2/23/2009 NA NA 628 3372 NA 212 Clark's Hill Reservoir 33.978533 -‐82.580983 3/10/2009 NA NA 578 2409 NA 213 Clark's Hill Reservoir 34.005283 -‐82.582233 4/15/2009 NA NA 530 2287 NA 214 Broad River at 33.983676 Anthony Shoals -‐82.645992 6/9/2009 NA NA NA NA female 215 Broad River at 33.983676 Anthony Shoals -‐82.645992 6/9/2009 NA NA NA 1871 female 216 Broad River at 33.983676 Anthony Shoals -‐82.645992 6/9/2009 NA NA NA NA male 217 Broad River at 33.983676 Anthony Shoals -‐82.645992 6/9/2009 NA NA NA NA male Page 86
Broad River Robust Redhorse reintroduction status Record Num. 218 Location Latitude Broad River at 33.983676 Anthony Shoals Longitude Capture Date Year Class Known Age Total Length (mm) Weight (g) Sex -‐82.645992 3/19/2010 1997 13 563 2890 female 219 Broad River at 33.983676 Anthony Shoals -‐82.645992 3/19/2010 1997 13 624 3434 male 220 Broad River at 33.983676 Anthony Shoals -‐82.645992 3/19/2010 1997 13 570 2490 female 221 Broad River at 33.983676 Anthony Shoals -‐82.645992 3/19/2010 1997 13 541 2442 male 222 Broad River at 33.983676 Anthony Shoals -‐82.645992 3/19/2010 1997 13 590 2614 male 223 Broad River at 33.983676 Anthony Shoals -‐82.645992 3/19/2010 1997 13 608 3006 male 224 Broad River at 33.983676 Anthony Shoals -‐82.645992 11/9/2010 1997 13 NA 2422 male 225 Broad River at 33.983676 Anthony Shoals -‐82.645992 11/9/2010 NA NA NA 2112 male 226 Broad River at 33.983676 Anthony Shoals -‐82.645992 11/9/2010 NA NA NA 1914 male 227 Broad River at 33.983676 Anthony Shoals -‐82.645992 11/9/2010 1997 14 NA 2468 male 228 Broad River at 33.983676 Anthony Shoals -‐82.645992 11/9/2010 1997 14 NA 2126 male 229 Broad River at 33.983676 Anthony Shoals -‐82.645992 2/25/2011 1997 14 690 4330 male 230 Broad River at 33.983676 Anthony Shoals -‐82.645992 2/25/2011 1997 14 662 4126 male 231 Broad River at 33.983676 Anthony Shoals -‐82.645992 3/4/2011 1997 14 555 2350 male 232 Broad River at 33.983676 Anthony Shoals -‐82.645992 3/4/2011 1997 14 564 2470 male 233 Broad River at 33.983676 Anthony Shoals -‐82.645992 3/25/2011 1997 14 610 3420 male 234 Broad River at 33.983676 Anthony Shoals -‐82.645992 3/25/2011 1997 14 579 2800 female 235 Broad River at 33.983676 Anthony Shoals -‐82.645992 3/25/2011 NA NA 535 1890 male 236 Broad River at 33.983676 Anthony Shoals -‐82.645992 3/25/2011 NA NA 620 3340 female 237 Broad River at 33.983676 Anthony Shoals -‐82.645992 3/25/2011 1997 14 566 2360 male Page 87
Broad River Robust Redhorse reintroduction status Record Num. 238 Location Latitude Broad River at 33.983676 Anthony Shoals Longitude Capture Date Year Class Known Age Total Length (mm) Weight (g) Sex -‐82.645992 3/25/2011 1997 14 564 2400 male 239 Broad River at 33.983676 Anthony Shoals -‐82.645992 3/25/2011 1997 14 615 3350 female 240 Broad River at 33.983676 Anthony Shoals -‐82.645992 3/25/2011 NA NA 566 2450 male 241 Broad River at 33.983676 Anthony Shoals -‐82.645992 3/25/2011 NA NA 563 2740 male 242 Broad River at 33.983676 Anthony Shoals -‐82.645992 3/25/2011 NA NA 544 1990 male Page 88
Broad River Robust Redhorse reintroduction status Appendix 3 Appendix 3. Summary of juvenile Robust Redhorse sampling information for 2009 and 2011 in the Broad River system, Georgia. Summary of 2009 sampling information 43. Hudson River approx. 0.6 river miles downstream of State Route 106. Day sample. Sampled approximately 100 m. All habitats were available at the site. Mid channel sand with little gravel and moderate flow. Worked edges with slow or no velocity. Lots of boulders and wood. (temp: 24.5 C; turbidity: 27.9 NTU; Sampled with seine, from 9:20-‐10:30; 4 people). 46. Hudson River, approx. 0.2 river miles downstream of State Route 106. Day sample. Sampled approx. 100 m in all available habitats. Collected young-‐of-‐year suckers along river right and river left in areas of large woody materials. (temp: 26 C; turbidity: 36.15 NTU ; sampled with seine, from 11:40-‐12:30; 4 people). 64. Middle Fork at Harrison Bridge Road. Day sample: Sampled 150 m of river. Young suckers collected in places with wood or where the water was deep-‐ not on shallow sandy runs. (temp: 20.5 C; turbidity: 10.8 NTU; sampled with seine, backpack electrofisher and dipnet, from 14:35-‐16:20; 260 shocking seconds; 4 people). 82. Middle Fork at State Route 51 (Sandy Cross Road). Day sample: Sampled approx. 100 m. Drizzling rain as sample was collected. Sucker collected by seine in thigh deep water with slow velocity. (temp: not recorded; turbidity: 12.55 NTU; sampled with seine, backpack electrofisher and dipnet, from 11:30-‐12:50; 236 shocking seconds; 4 people). 87. Middle Fork at Atkinson Bridge Road. Day sample. Sampled approximately 65 m. Rain fairly steady through the second half of this sample. Bottom substrate at the site mostly sand except for a few spots with some boulder/bedrock. Young-‐of-‐year suckers found in shallow backwater area. Larger suckers in deeper pools. (temp: not recorded; turbidity: 11.2 NTU; sampled with seine, backpack electrofisher and dipnet, from 13:50-‐
14:46; 304 shocking seconds; 4 people). Page 89
Broad River Robust Redhorse reintroduction status 134. Hudson River at State Route 106. Day sample. Sampled approximately 70 m. Caught young-‐of-‐year suckers in bedrock riffle area with refugial pools behind boulders with Hypentelium. Caught three 25-‐36cm Moxostoma collapsum in waist deep pool woody material (temp: 21 C; turbidity: 9.77 NTU; sampled with seine, backpack electrofisher and dipnet, from 9:20-‐10:45; 300 shocking seconds; 4 people). 146. Hudson River at State Route 29. Day sample. Sampled approximately 75 m. Seined two small suckers in slow shallow area, both preserved. A larger Moxostoma collapsum (approx. 22 cm) seined up in deeper water, was released. (temp: 22 C; turbidity: 9.22 NTU; sampled with seine, backpack electrofisher and dipnet, from 9:00-‐10:30; 333 shocking seconds; 4 people). 171. Broad River approx. 1.6 air miles upstream of State Route 281. Day sample. Sampled approximately 140 m. This site had a large hole on the river right side with a big pile of large woody material (large tree was laying in the water) where we saw some large gar, carp, suckers and bass hanging out. At least 1 pair of Moxostoma were relatively large with orange-‐ish/coppery sides, these may have been robustum. We captured one carp (Cyprinus carpio) and one Brassy Jumprock (Moxostoma sp.; 36 cm, released). Captured one young-‐of-‐year sucker in some large woody material. (temp: 26 C; turbidity: 5.4 NTU; sampled with seine, backpack electrofisher and dipnet, from 14:45-‐16:00; 269 shocking seconds; 4 people). 172. Broad River approx. 1.7 air miles upstream of State Route 281. Day sample. Sampled approximately 160 m. Sampled all available habitat. Most of the bottom substrate was sand w/silt some spots with boulders, caught no suckers. (temp: 27 C; turbidity: 11.0 NTU; sampled with seine, from 15:40-‐16:30; 4 people). 173. Broad River approximately 1.9 air miles upstream of State Route 281. Day sample. Sampled approximately 140 m. Collected a young-‐of-‐year sucker in low or no flow and woody debris. (temp: 27 C; turbidity: 11.0 NTU; sampled with seine, from 13:30-‐14:45; 4 people). 182. Broad River approx. 3.3 air miles upstream of State Route 281. Day Sample. Sampled approximately 140 m. Captured young-‐of-‐year suckers in large woody material, along with one 12cm Minytrema that was released (temp: 23.5 C; turbidity: 12.15 NTU; sampled with seine, from 10:30-‐11:55; 4 people). Page 90
Broad River Robust Redhorse reintroduction status 197. Broad River approx. 0.1 river miles downstream of confluence of Hudson River. Day sample. Sampled approximately 50 m. Shocking produced a few young-‐of-‐year suckers in areas with large woody material, none were collected while seining. Site has big shallow mid-‐channel sand bar, with small exposed patches in middle. Most of flow around channel edges-‐ some pools thigh deep. (temp: 23 C; turbidity: 6.9 NTU; sampled with seine, backpack electrofisher and dipnet, from 10:15-‐11:45; 370 shocking seconds; 4 people). 288. Broad River approx. 1.8 river miles downstream of State Route 172. Day sample. Sampled approximately 150 m. Worked slow area at the top around bar and big boulders, then worked some swift water habitat in shoal. Seined slow water or eddy pockets within shoal. This site is mostly boulder-‐bedrock, so we sampled runs and pools/refugia downstream of bars/boulders. Added a companion to site 288 (approx. 0.2 river miles downstream of 288) to add missing large woody material areas with slow water. This patch was collected first around the LWD with a shocker. We collected one adult female Moxostoma collapsum and missed two one of which swam downstream the other went farther under the large woody material. Then immediately upstream we did a seine haul and collected 11 more M. collapsum (7 males and 4 females). All M. collapsum captured were >20 cm in SL, and had varying degrees of color and notched-‐ness in the lower lip. (temp: 27 C; turbidity: 7.1 NTU; sampled with seine, from 13:50-‐15:00; 4 people). 289. Broad River approx. 1.6 river miles downstream of State Route 172. Day sample. Sampled approximately 140 m. Collected and released one Minytrema (14 cm) and one Moxostoma collapsum (12 cm) from under large woody material when shocking in a deeper hole along river margin. (temp: 23.5 C; turbidity: 7.9 NTU; sampled with seine, backpack electrofisher and dipnet, from 10:40-‐12:25; 341 shocking seconds; 4 people). 313. Broad River approx. 2.8 river miles upstream of State Route 77. Day sample. Sampled approximately 115 m. Collected and released Moxostoma collapsum (16 cm, 17 cm) and Minytrema (15 cm) in approximately 50-‐60 cm of water near woody material. No young-‐of-‐year suckers captured. (temp: 24 C; turbidity: 4.3 NTU; sampled with seine, backpack electrofisher and dipnet, from 17:00-‐18:10; 651 shocking seconds; 4 people). Page 91
Broad River Robust Redhorse reintroduction status 324. Broad River approx. 4.6 river miles upstream of State Route 77. Day sample. Sampled approximately 110 m. Caught five female Moxostoma collapsum (15-‐26 cm) under a large amount of large woody material with a root of an old tree near the bank, missed at least five more adult Moxostoma in this same location (temp: 24 C; turbidity: 5.5 NTU; sampled with seine, backpack electrofisher and dipnet, from 14:30-‐15:35; 331 shocking seconds; 4 people). 326. Broad River approx. 4.9 river miles upstream of State Route 77. Day sample. Sampled approximately 90 m. Collected all available habitat, mostly consisting of areas with sand and some large woody material. No suckers captured. (temp: 24 C; turbidity: 4.6 NTU; sampled with seine, backpack electrofisher and dipnet, from 12:10-‐13:40; 629 shocking seconds; 4 people). 461. Broad River approx. 1.0 river miles downstream of State Route 17. Day sample. Sampled approximately 80 m. Sampled all available habitats (temp: 29 C; turbidity: 6.2 NTU; sampled with seine, from 13:30-‐14:45; 4 people). 465. Broad River approx. 0.4 river miles downstream of State Route 17. Day sample. Sampled approximately 90 m. Sampled all available habitats, some of the woody habitats were deep and hard to sample. (temp: 29 C; turbidity: 8.1 NTU; sampled with seine, backpack electrofisher and dipnet, from 11:50-‐12:30; 211 shocking seconds; 4 people). Power line. Broad River at Power Line spawning site. Day sample. We collected using 3 seine hauls through the river left channel margin and preserved three young-‐of-‐year suckers. One seine haul was in a slightly backwater area ds of the gravel where Robust Redhorse may have spawned this spring and have spawned in the past. (temp: 27 C; turbidity: not sampled; sampled with seine; 4 people). 502. Middle Fork of the Broad River at State Route 106. Day sample. Sampled 185m. Collected young-‐of year suckers in backwater with low flow and association with large woody material also collected a young-‐of-‐year jumprock in swifter water (temp: 20.5 C; turbidity: 10.8 NTU; sampled with seine, backpack electrofisher and dipnet, from 12:00-‐13:40; 371 shocking seconds; 4 people). Page 92
Broad River Robust Redhorse reintroduction status Summary of 2011 sampling information 1. North Fork Broad River at Highway 145. Day sample. Sampled approximately 150 m, from 75 m downstream of Highway 145 bridge to approximately 100 m upstream. Habitats sampled included areas in deep swift water upstream, marginal slow, no-‐flow areas with large woody material, gravel runs, sandy, and mid-‐channel areas over sand with flow. (sampled with seine, from 18:30-‐19:45; 3 people.) Night sample. Sampled through a similar area as in the day sample. (sampled with seine, from 21:10-‐22:20; 3 people.) 3. Middle Fork upstream of Highway 29. Day sample. Sampled this location on 2 different days (8/18 and 8/30). 8/18: Sampled in the upstream reaches of the spawning area in the boulder bedrock area and upstream looking upstream of any spawning area used by robust redhorse. Collected five young-‐of-‐year suckers while seining through shallow habitat over sand and in flow refugia areas behind large boulders. 8/30: Sampled approximately 175m of river from main bend used for spawning downstream to include some large patches of margin with slow water and large woody materials. (8/18: sampled with seine, from 19:00-‐
20:00, 2 people; 8/30: sampled with seine, from 16:15-‐18:00; 3 people.). Night sample. Sampled similar areas as those sampled during the day on 8/30. Caught suckers in areas along river right margin and river left near large woody material. (sampled with seine, from 21:20-‐22:30; 2 people.) 4. Middle Fork at Highway 29. Day sample. Sampled approximately 120 m of river upstream and downstream of the Highway 29 bridge. Missed capturing one approximately 15 cm sucker that was holding under a large bedrock ledge in approximately 60 cm of water. This sucker had dark fins. (sampled with seine, backpack electrofisher and dipnet, from 16:20-‐18:05; 329 shocking seconds; 3 people.) 5. Broad River at Highway 281. Day sample. Sampled approximately 100m of river mostly downstream of the bridge. Caught suckers in downstream hauls over fine gravel, in backwater seine hauls into large woody material, and in kick-‐sets in rocky habitat or pools in the flow refugia behind bedrock/boulders. Page 93
Broad River Robust Redhorse reintroduction status Night sample. Sampled areas of sand, boulder bedrock ledges and pools. (sampled with seine, from 19:00-‐20:00; 3 people.) 6. Broad River at mouth of Vineyard Creek. Night sample. Sampled with a light trap and using a dipnet and spot-‐lighting. No fish of any species were caught using the light trap. The light trap was set in flowing water for two hours, and in a marginal no-‐flow area for 2 hours. Additionally, multiple different colored (red, blue, green, yellow) chemical light sticks were places approximately two meters apart from one another in a no flow area along the river left to check to see if the lights attracted additional fish not captured by the light trap. We caught four young-‐of-‐year suckers, ranging from 37-‐44 mm in standard length. Sampled along the river left margin in low flow areas. (temp: not recorded; turbidity 10.2 NTU; sampled with light trap and dipnet, from 23:30-‐01:00; 2 people.) 7. Broad River upstream of Highway 281 (Boy’s and Girl’s Club, Camp Kiwanis). Day sample. Sampled approximately 120 m of river at the downstream “bend” of the property where there is a large bedrock ledge and drop (called “flat rock” by the Boy’s and Girl’s Club). After sampling this area, we also moved upstream and additionally sampled another 100 m upstream in an area with a bedrock rock face along river left (referred to as the “volleyball court” put in by the Boy’s and Girl’s Club personnel). During higher flows this area would be a long pool along the river left. We made a voucher collection of all species collected from this area, which included, but was not limited to one Pylodictus olivaris, several Carpiodes and all suckers excluding Hypentelium (temp: 19.5 C; turbidity: 6.0 NTU; sampled with seine, backpack electrofisher and dipnet, from 13:40-‐1515; 153 shocking seconds; 5 people.) 8. Broad River within 1 km downstream of downstream spawning site. Day sample. Most suckers here were captured around large woody materials on river right and river left margins of the channel, in around 30 cm of water. The areas had some flow with sand and fine sediments as a substrate. (temp: 14 C; turbidity: 6.7 NTU; sampled with seine, backpack electrofisher and dipnet, from 8:45-‐9:45; 262 shocking seconds; 4 people.) 9. North Fork within 1 km downstream of spawning site. Day sample. This site contained very few areas of low flow, but had a fairly decent amount of large woody material that could have created flow refugia areas for small suckers to use. The Minytrema were captured in a cluster of large woody material on river right downstream of the fish Page 94
Broad River Robust Redhorse reintroduction status weir. (temp: 9 C; turbidity: 6.1 NTU; sampled with seine, backpack electrofisher and dipnet, from 10:05-‐11:07; 310 shocking seconds; 4 people.) 10. M01 – Broad River immediately downstream of its junction with the North Fork. Day sample. This site was just downstream of the junction of the North Fork and the Middle Fork of the Broad River. Sampled 110 m. The river is fairly wide at this site and allowed for a large amount of large woody material and low flow areas along a mid-‐channel sand bar and along both river right and river left. (temp: 10.5 C; turbidity: 5.8 NTU; sampled with seine, backpack electrofisher and dipnet, from 11:45-‐12:45; 291 shocking seconds; 4 people.) 11. T01 – Middle Fork of the Broad River upstream of its junction from the North Fork. Day sample. This site was on the Broad River just upstream of the mouth of the North Fork. The upper portion of the reach was mostly boulder bedrock, and the lower section was wider with lower flow and sandy and silt bottoms. We primarily focused our sample along the river right edge. Young-‐of-‐year suckers were collected in large woody material in a backwater area on river right of a sand island in depths around or less than 30 cm. The brassy jumprock was collected in the flow refugia area just downstream of a large boulder. (temp: 11 C; turbidity: 6.3 NTU; sampled with seine, backpack electrofisher and dipnet, from 13:30-‐14:10; 258 shocking seconds; 4 people.) 12. T03 – Unnamed tributary to Broad River, approximately 0.38 river miles downstream of Bonds Bridge Road. This tributary flowed down along the edge of a very manicured lawn, and appeared dry where it exited into the Broad River. Due to its small size and the current size of the young-‐of-‐year suckers we did not sample this tributary. 13. M05 – Broad River, approximately 0.66 river miles downstream of Bonds Bridge Road. Day sample. This site included an area bounded at the downstream edge by a bedrock edge and upstream by a deep area with large boulder / bedrock substrate making sampling inefficient. Young-‐of-‐year suckers were captured in areas of large woody material along river left and river right. The young-‐of-‐year suckers in this sample were captured in deeper water than those in other samples, but in the shallowest areas available in the areas where they were captured. (sampled with seine, backpack electrofisher and dipnet, from 15:20-‐16:35; 420 shocking seconds; 4 people.) 14. M06 – Broad River, approximately1.34 river miles upstream of Highway 29. Page 95
Broad River Robust Redhorse reintroduction status Day sample. This site was mostly flat with no riffle-‐type habitat. Both river right and river left margins had areas of large woody material. We collected suckers in two different areas in conjunction with large woody material and no to low flow. (temp: 16 C; turbidity: 5.9 NTU; sampled with seine, backpack electrofisher and dipnet, from 10:20-‐11:15; 274 shocking seconds; 4 people.) 15. M08 – Broad River, approximately1.34 river miles upstream of Highway 29. Day sample. This site contained a pool that was approximately six meters in length and three meters wide with a depth of about 60-‐70 cm. This pool was just upstream of a bedrock bank / wall along the river left edge that contained areas of >70 cm of water. In this pool was approximately 25 or more larger suckers. We captured 16 individuals in this group. The group was mixed species including Minytrema melanops, Moxostoma collapsum, and M. sp. (Brassy Jumprocks) and also included a range of sizes from 150-‐300mm standard length. Most of the young-‐of-‐year suckers were captured in area with no or low flow in association with large woody material. Sampled this (temp: 19 C; turbidity: 6.6 NTU; sampled with seine, backpack electrofisher and dipnet, from 12:30-‐14:15; 273 shocking seconds; 4 people.) 16. T06 – Tributary to the Broad River, approx. 0.18 river miles upstream of Highway 29. This tributary was less than 50 cm in width, and most of its depth appeared to be less than 25 cm in depth. Due to its small size and the current size of the young-‐of-‐year suckers we did not sample this tributary. 17. T07 – Tributary to the Broad River downstream of Highway 29 Day sample. Large pool with a perched culvert at the upstream end, likely preventing fish passage at lower flows. Perch on the culvert appeared to be about 70 cm above the water line. Upstream of the culvert is a large pool caused by a beaver dam built against the upstream end of the culvert. The beaver dam is about 40 cm in height above the culvert bottom. Sampled the approximately 20 m reach between the river mouth upstream to the culvert. The substrate bottom was fine sediment covering rip-‐rap and other concrete debris. We collected numerous species of sunfish (Lepomis) along with bullhead (Ameiurus sp.), Chain Pickerel (Esox niger), Lake Chubsuckers (Erimyzon oblongus), Whitefin Shiner (Cyprinella nivea), and Black-‐banded Darters (Percina nigrofasciata). No catostomids, besides Erimyzon, were captured in this reach. (temp: 16 C; turbidity: not recorded; sampled with seine, backpack electrofisher and dipnet, from 15:20-‐15:40; 135 shocking seconds; 4 people.) Page 96
Broad River Robust Redhorse reintroduction status 18. H01 – Hudson River at Highway 29. Day sample. Sampled approximately 175m of river upstream and downstream of Highway 29 bridge. We sampled all available habitat including riffles and mid-‐channel and marginal large woody material downstream of bridge. We also sampled additional around some large woody material upstream of bridge along river left where we captured Pomoxis nigromaculatus. Cows had access and were readily crossing the river downstream of the bridge. (temp: 15 C; turbidity estimated at approximately 7 NTU; sampled with seine, backpack electrofisher and dipnet, from 10:15-‐12:30; 930 shocking seconds; 4 people.) Page 97
Broad River Robust Redhorse reintroduction status Appendix 4 Appendix 4. The probability (1-‐odds) that an individual fish with the given total length (mm) is less than 12 years old presented as means (credible interval). Total Length (mm) 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 Probability (p) < 12 Years Old 0.9988 (0.9922-‐1) 0.9988 (0.9918-‐1) 0.9987 (0.9914-‐1) 0.9986 (0.9911-‐1) 0.9986 (0.9907-‐1) 0.9985 (0.9903-‐1) 0.9984 (0.9898-‐1) 0.9983 (0.9894-‐1) 0.9982 (0.9889-‐1) 0.9981 (0.9884-‐1) 0.998 (0.9879-‐1) 0.9979 (0.9874-‐1) 0.9978 (0.9868-‐1) 0.9977 (0.9862-‐1) 0.9976 (0.9856-‐1) 0.9974 (0.985-‐1) 0.9973 (0.9843-‐1) 0.9971 (0.9836-‐1) 0.997 (0.9829-‐1) 0.9968 (0.9822-‐1) 0.9966 (0.9813-‐1) 0.9965 (0.9805-‐1) 0.9963 (0.9797-‐1) 0.9961 (0.9788-‐1) 0.9958 (0.9778-‐1) 0.9956 (0.9769-‐1) 0.9953 (0.9758-‐0.9999) 0.9951 (0.9748-‐0.9999) 0.9948 (0.9737-‐0.9999) 0.9945 (0.9725-‐0.9999) 0.9942 (0.9713-‐0.9999) 0.9938 (0.97-‐0.9999) 0.9935 (0.9687-‐0.9999) 0.9931 (0.9673-‐0.9999) 0.9927 (0.9658-‐0.9999) 0.9923 (0.9643-‐0.9998) 0.9918 (0.9627-‐0.9998) Page 98
Broad River Robust Redhorse reintroduction status Total Length (mm) 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 Probability (p) < 12 Years Old 0.9913 (0.9611-‐0.9998) 0.9908 (0.9593-‐0.9998) 0.9903 (0.9575-‐0.9997) 0.9897 (0.9557-‐0.9997) 0.9891 (0.9537-‐0.9997) 0.9885 (0.9516-‐0.9996) 0.9878 (0.9494-‐0.9996) 0.987 (0.9472-‐0.9995) 0.9862 (0.9449-‐0.9995) 0.9854 (0.9425-‐0.9994) 0.9845 (0.9399-‐0.9993) 0.9836 (0.9372-‐0.9993) 0.9826 (0.9345-‐0.9992) 0.9815 (0.9315-‐0.9991) 0.9804 (0.9284-‐0.9989) 0.9792 (0.9253-‐0.9988) 0.9779 (0.922-‐0.9987) 0.9765 (0.9186-‐0.9985) 0.975 (0.915-‐0.9983) 0.9735 (0.9112-‐0.9981) 0.9718 (0.9073-‐0.9979) 0.9701 (0.9033-‐0.9976) 0.9682 (0.8989-‐0.9973) 0.9662 (0.8945-‐0.997) 0.9641 (0.8898-‐0.9966) 0.9618 (0.8849-‐0.9962) 0.9594 (0.8799-‐0.9957) 0.9568 (0.8746-‐0.9952) 0.9541 (0.8691-‐0.9946) 0.9512 (0.8633-‐0.9939) 0.9481 (0.8573-‐0.9932) 0.9448 (0.851-‐0.9923) 0.9413 (0.8445-‐0.9914) 0.9375 (0.8378-‐0.9904) 0.9336 (0.8308-‐0.9893) 0.9293 (0.8232-‐0.988) 0.9248 (0.8155-‐0.9866) 0.92 (0.8074-‐0.9851) 0.915 (0.799-‐0.9834) 0.9096 (0.7901-‐0.9815) 0.9038 (0.7808-‐0.9793) Page 99
Broad River Robust Redhorse reintroduction status Total Length (mm) 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 Probability (p) < 12 Years Old 0.0353 (0.0011-‐0.1522) 0.0334 (0.0009-‐0.1464) 0.0317 (0.0008-‐0.1411) 0.03 (0.0007-‐0.1356) 0.0284 (0.0007-‐0.1305) 0.0269 (0.0006-‐0.1256) 0.0255 (0.0005-‐0.1208) 0.0241 (0.0005-‐0.1161) 0.0228 (0.0004-‐0.1115) 0.0216 (0.0004-‐0.1071) 0.0205 (0.0003-‐0.1029) 0.0194 (0.0003-‐0.0989) 0.0184 (0.0003-‐0.0949) 0.0175 (0.0002-‐0.0911) 0.0166 (0.0002-‐0.0875) 0.0157 (0.0002-‐0.084) 0.0149 (0.0002-‐0.0807) 0.0141 (0.0001-‐0.0775) 0.0134 (0.0001-‐0.0744) 0.0127 (0.0001-‐0.0714) 0.0121 (0.0001-‐0.0685) 0.0114 (0.0001-‐0.0658) 0.0109 (0.0001-‐0.0631) 0.0103 (0.0001-‐0.0606) 0.0098 (0.0001-‐0.0581) 0.0093 (0.0001-‐0.0557) 0.0088 (0-‐0.0534) 0.0084 (0-‐0.0512) 0.008 (0-‐0.0491) 0.0076 (0-‐0.0471) 0.0072 (0-‐0.0452) 0.0068 (0-‐0.0434) 0.0065 (0-‐0.0416) 0.0062 (0-‐0.0398) 0.0059 (0-‐0.0382) 0.0056 (0-‐0.0366) 0.0053 (0-‐0.0351) 0.005 (0-‐0.0336) 0.0048 (0-‐0.0322) 0.0046 (0-‐0.0308) 0.0043 (0-‐0.0296) Page 102
Broad River Robust Redhorse reintroduction status Total Length (mm) 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 Probability (p) < 12 Years Old 0.0041 (0-‐0.0283) 0.0039 (0-‐0.0271) 0.0037 (0-‐0.026) 0.0036 (0-‐0.0249) 0.0034 (0-‐0.0239) 0.0032 (0-‐0.0229) 0.0031 (0-‐0.022) 0.0029 (0-‐0.021) 0.0028 (0-‐0.0202) 0.0027 (0-‐0.0193) 0.0025 (0-‐0.0185) 0.0024 (0-‐0.0177) 0.0023 (0-‐0.017) 0.0022 (0-‐0.0163) 0.0021 (0-‐0.0156) 0.002 (0-‐0.0149) 0.0019 (0-‐0.0143) 0.0018 (0-‐0.0137) 0.0017 (0-‐0.0131) 0.0017 (0-‐0.0126) 0.0016 (0-‐0.012) 0.0015 (0-‐0.0115) 0.0014 (0-‐0.0111) 0.0014 (0-‐0.0106) 0.0013 (0-‐0.0102) 0.0013 (0-‐0.0097) 0.0012 (0-‐0.0093) 0.0011 (0-‐0.0089) 0.0011 (0-‐0.0086) 0.001 (0-‐0.0082) 0.001 (0-‐0.0078) 0.001 (0-‐0.0075) 0.0009 (0-‐0.0072) 0.0009 (0-‐0.0069) 0.0008 (0-‐0.0066) 0.0008 (0-‐0.0063) 0.0008 (0-‐0.0061) 0.0007 (0-‐0.0058) 0.0007 (0-‐0.0056) 0.0007 (0-‐0.0053) 0.0006 (0-‐0.0051) Page 103
Broad River Robust Redhorse reintroduction status Total Length (mm) 692 693 694 695 696 697 698 699 700 Probability (p) < 12 Years Old 0.0006 (0-‐0.0049) 0.0006 (0-‐0.0047) 0.0006 (0-‐0.0045) 0.0005 (0-‐0.0043) 0.0005 (0-‐0.0041) 0.0005 (0-‐0.004) 0.0005 (0-‐0.0038) 0.0004 (0-‐0.0036) 0.0004 (0-‐0.0035) Page 104

Moxostoma robustum - Robust Redhorse Conservation Committee

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