Queen Charlotte Sound, New Zealand - E

Transcription

Queen Charlotte Sound, New Zealand: A Habitat for
Marine Mammals
Interim Report
Cheryl L. Cross
Coastal-Marine Research Group
Massey University
January 2013
DOC Interim Report
Cheryl L. Cross
PhD Candidate:
Cheryl L. Cross
Supervisors:
Advisor:
Dr. Karen A. Stockin
Dr. Deanna Clement
Dr. Todd Dennis
Study Location:
Queen Charlotte Sound, Marlborough Sounds, NZ
1. INTRODUCTION
The current study in Queen Charlotte Sound, South Island, New Zealand (41° 11 S, 174°11 E;
herein referred to as QCS) is focused on distribution, density and habitat use of marine
mammals, and associated anthropogenic influence and tourism activity. The focal species
include the bottlenose, Tursiops truncatus, Hector’s Cephalorhynchus hectori hectori, dusky
Lagenorhynchus obscurus, and common dolphin Delphinus sp;. as well as killer whales (Orcinus
orca), and New Zealand fur seals (Arctocephalus forsteri). Dolphin tourism has been active for
two decades in QCS, and despite the variety of marine life present, a baseline study investigating
species’ occurrence and habitat use, and an examination of tourism activity has not been
conducted. This ensuing research will thus begin to bridge important knowledge gaps on
relatively unstudied dolphin populations in New Zealand.
Distribution
Bottlenose Dolphin
Bottlenose dolphins have a cosmopolitan distribution occupying tropical and temperate latitudes
extending from 45°N to 45°S (Figure 1). They are considered one of the most adaptable
Delphinid species, inhabiting pelagic and coastal oceanic waters as well as bays, estuaries and
the lower reaches of rivers (Kenney, 1990; Reeves et al. 2002). For example, bottlenose
dolphins off Sarasota, Florida, USA, occupy shallow bays and seagrass beds during springtime
and predominate in channels and coastal waters during winter months (Barros & Wells, 1998).
Figure 1. Worldwide distribution of bottlenose dolphins.
Source: IUCN http://www.cms.int/reports/small_cetaceans/data/t_truncatus/t_truncatus.htm
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A minimum worldwide population estimate of 600,000 has been estimated for T. truncatus based
on the summation of available abundance estimates (Hammond et al. 2008a). In New Zealand,
three distinct subpopulations exist in Northland, Fiordland, and the Marlborough Sounds
(Tezanos-Pinto et al., 2009). The Fiordland subpopulation was estimated to be 205 individuals
(Currey et al. 2011). Photographic evidence in Doubtful Sound, NZ indicated a population
estimate of 58 individuals (Williams et al. 1993). An estimated 385 individuals utilize the area in
the greater Marlborough Sounds region (Merriman et al. 2009).
Hector’s Dolphin
The Hector’s dolphin is endemic to the coastal waters of the South Island of New Zealand and
has one of the most limited ranges of all Delphinids (Brager et al. 2002, Figure 2). They are
found in small groups along the West Coast of the South Island (Brager & Schneider, 1998; E.
Slooten et al. 2004, along the East coast (Martinez, 2010; Slooten et al. 2006), the Southern tip of
the South Island (Bejder & Dawson 2001), and in the QCS (personal observation).
Figure 2. Distribution and range of Hector’s and Maui’s dolphins. Hector’s dolphins are distributed in
the South Island and Maui’s dolphin in the North. Red represents the species’ range, and green
represents protected waters. Source: www.wwf.org.nz
Dusky Dolphin
Dusky dolphins are restricted in range to the southern hemisphere including southern South
America, southern Africa and New Zealand (Figure 3, Reeves et al. 2002). In New Zealand, the
population is distributed throughout the country, but limited information is available except in
well-studied areas around the Kaikoura peninsula and within Admiralty Bay in the Marlborough
Sounds (Würsig et al. 2007). Seasonal shifts in distribution between Kaikoura and Admiralty
Bay have been identified (Markowitz et al. 2004).
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Figure 3. Worldwide distribution of Dusky dolphins
Source: IUCN http://www.cms.int/reports/small_cetaceans/data/l_obscurus/l_obscurus.htm
Common Dolphin
Common dolphins range in distribution from approximately 60°N to 50°S latitude including
tropical and temperate, nearshore and pelagic waters (Figure 4) (Reeves et al. 2002). Distribution
studies in New Zealand have occurred primarily within the Hauraki Gulf and the Bay of Plenty
(Neumann, 2001; Stockin & Orams, 2009a), however, their range extends throughout waters
around the country.
Figure 4. Worldwide distribution of common dolphins.
Source: IUCN http://www.cms.int/reports/small_cetaceans/data/d_delphis/d_delphis.htm
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Distribution and Environmental Features
Numerous studies have shown the correlation with the distribution of various cetacean species
and a range of physical aspects of the marine environment including sea surface temperature
(Ferguson et al. 2006; Hastie et al. 2005; MacLeod et al. 2007; Selzer & Payne, 1988), salinity
(Ferguson, et al., 2006; Selzer & Payne, 1988), depth (Azzellino et al. 2008; Canadas et al. 2002;
Hastie et al. 2005; Ingram et al. 2007) bottom slope (Azzellino et al. 2008; Canadas et al. 2002;
Ingram et al. 2007; Yen et al.2004) and distance from shore (MacLeod et al. 2007; Yen et al.
2004). Marine mammal distribution can be either directly or indirectly related to such
parameters, as it is commonly believed that distribution is dependent upon the availability of
sufficient prey (Davis et al. 2002; Doksaeter et al. 2007; Jaquet & Gendron, 2002). The
collection of physical data may be more accessible and in the absence of prey data, physical
parameters can be used as indicators or predictors of cetacean species distribution (Hastie et al.
2005; Ready et al. 2010; Redfern et al. 2006). Prediction and mapping of potential suitable
habitats for threatened and endangered species is important for monitoring, management and
conservation efforts, however, data on such species are often sparse and clustered, making
modelling efforts difficult (Kumar & Stohlgren, 2009).
Bottlenose Dolphin
The bottlenose dolphin has been included in several distribution and habitat use studies
worldwide (Balance et al. 2006; Baumgartner et al. 2001; Canadas et al. 2002; Davis et al. 2002;
Garrison et al. in press; Hamazaki, 2002; Torres et al. 2003). Correlations between bottlenose
dolphin distribution and bathymetric features indicate a high slope gradient in the Northwest
Atlantic Ocean and the Mediterranean (Canadas et al. 2002; Hamazaki, 2002) and shallow
bottom depth in the Gulf of Mexico (Baumgartner et al. 2001; Davis et al. 2002). The
distribution of different morphotypes (offshore and coastal) in the Northwest Atlantic Ocean
varies and is delineated by depth (Garrison et al. 2003; Torres et al. 2003). Associations with
low surface salinity values (Garrison et al. in press) and warmer surface temperatures
(Hamazaki, 2002) in the Northwest Atlantic Ocean have been exhibited. Similar trends may be
exhibited in different geographic regions for the same species; however, it is important to
understand the unique combination of physical and biological oceanographic features that
contribute to the productivity of a region, making it a suitable habitat for cetaceans (Ballance et
al. 2006).
In the Bay of Islands, NZ, (Constantine, 2002) found seasonal shifts in temperature and depth
values associated with bottlenose dolphin habitat. Similarly, in Doubtful Sound, NZ Schneider
(1999) found that bottlenose dolphins tend to shift to regions with the warmest seasonal
temperature values. Investigations were made into the habitat parameters associated with
bottlenose sightings across the greater Marlborough Sounds region (Merriman, 2007). Variation
among temperature and salinity values were noted across the Sounds, however there was no
seasonal variation in habitat use among bottlenose dolphins with regards to physical features.
Hector’s Dolphin
Distribution and habitat studies for Hector’s dolphins indicate a strong association of species
occurrence with close proximity to the coast (Rayment et al. 2011; Rayment et al. 2010).
Shallow depth is a significant factor in determining distribution (Brager et al. 2003; Rayment et
al. 2011; Rayment et al. 2010), however it is more influential during the summer months
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(Rayment et al. 2010). Hector’s dolphins tend to stay within relatively small areas (Bejder &
Dawson, 2001) and prefer warmer, turbid waters (Brager et al. 2003). Distribution was found to
occur along oceanographic hotspots within the Banks Peninsula (Clement, 2005).
In examining the population of Hector’s dolphins in QCS, the presence of habitat partitioning
will be investigated. By considering parameters that have been examined in previous studies
elsewhere in New Zealand, Hector’s dolphin habitat preference in QCS can be compared with
other populations.
Taxonomy and Conservation Status
Bottlenose Dolphin
Mitochondrial DNA analyses and osteological differences have indicated two genetically
distinct, reproductively isolated species of Tursiops (T. truncatus and T. aduncus) (Wang et al.
1999,2000a) which were once considered to be a single species (T. truncatus) worldwide.
Furthermore, morphological distinctions between the two species such as snout to eye length and
rostrum length were confirmed (Wang et al. 2000a, 2000b). However, the taxonomy of Tursiops
still remains rather unclear with the existence of geographic variation. For example, coastal and
offshore morphotypes exist in the North Atlantic Ocean. The offshore morphotype is
characterized by higher haemoglobin concentration, packed cell volume, and red blood cell count
(Duffield et al. 1983; Hersch & Duffield, 1990). It is 15% longer with a proportionately shorter
snout, small flippers, and a wider skull and rostrum (Hersch & Duffield, 1990; Mead & Potter,
1995) and differences in nuclear and mitochondrial markers genetically distinguish the two
morphotypes in the western North Atlantic Ocean (Hoelzel et al. 1998). The existence of a new
species of Tursiops (T. australis sp. nov.), endemic to a small region to South and Southeast
Australian waters, has been established based on the presence of morphological and molecular
differences between the other species present within Australian waters (Charlton-Robb et al.
2011). In New Zealand waters, coastal populations are highly isolated, but yet retain a high
degree of genetic diversity. The distinct ecotypes that are present within the Western North
Atlantic Ocean may not reflect the same patterns in New Zealand or elsewhere (Tezanos-Pinto et
al. 2009).
According to the IUCN Red List for threatened species, the status of the bottlenose dolphin (T.
truncatus) is listed as that of Least Concern (Hammond et al. 2008a). However, despite their
global distribution and lack of apparent threat of extinction on a global scale, regional
populations of this species are threatened primarily due to anthropogenic influences (Currey et
al. 2009). The New Zealand threat classification system has been established to complement the
IUCN Red Lists and provide finer detail of threat status for regional populations in New Zealand.
According to this system, bottlenose dolphins are classified as Nationally Endangered because of
the low abundance of regional populations and apparent decline in two populations (Baker et al.
2010). The Fiordland bottlenose dolphins in particular meet the criteria for classification as
critically endangered based on recent population models indicating 123 mature individuals and
an estimated rate of decline of 31.4% over one generation (Currey et al. 2009). Furthermore,
recent findings indicate a decline in the local Bay of Islands population (Tezanos-Pinto et al. in
press).
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Hector’s Dolphin
Based on genetic analyses of mtDNA population structure, four regional populations of Hector’s
dolphins have been shown to display little female dispersal (Pichler, 2002). The geographic
isolation and genetic differences of the north island population in addition to recent evidence of
morphological differences has led to the separation as two subspecies (Baker et al. 2002). The
Hector’s dolphin (Cephalorhynchus hectori hectori) populates locations throughout the South
Island of New Zealand (Pichler, 2002). The Maui’s dolphin (C. h. maui) inhabits the North
Island and is characterized by a larger skull, including a longer and wider rostrum as well as a
longer average total body length than that of C. h. hectori (Baker et al. 2002). The North Island
population as well as the East Coast populations of the South Island have displayed significant
decline in genetic diversity. Further decline in genetic diversity as well as population is predicted
(Pichler & Baker, 2000).
Data from recent aerial surveys indicate a population estimate of 7,270 Hector’s dolphins for the
entire South Island (Slooten et al. 2004). Back calculation using a population viability analysis
and the catch rate of Hector’s dolphins in gillnets indicates that the current population is 27% of
the 1970 population level (Slooten, 2007). This decrease in population (greater than 50%)
qualifies Hector’s dolphins as Endangered on the IUCN Red List (Baker et al. 2010; Reeves et
al. 2008; Slooten, 2007). Likewise, the Hector’s dolphin is classified as Nationally Endangered
according to the New Zealand threat classification system (Baker et al. 2010). A reduction in
bycatch to levels close to zero will allow for a predicted increase to 50% of the 1970 population
levels (Slooten, 2007).
Both New Zealand bottlenose and Hector’s dolphins maintain low population numbers with
evidence of recent decline. Suggested reasons for the decline of the bottlenose population in the
Bay of Islands include an increase in mortality of the whole North Island population which could
potentially be attributed to anthropogenic influence. Furthermore, there is evidence of a change
in habitat use within the region which could be attributed to alterations in prey availability,
environmental cues, or anthropogenic shifts (Tezanos-Pinto et al. in press). Current information
on these factors within QCS is necessary in order to better understand any future changes in
dolphin abundance or habitat.
Dusky and Common Dolphins
Three subspecies of dusky dolphins exist; L. obscurus obscurus in southern Africa, L .o. fitzroyi
in southern South America and an unnamed subspecies in New Zealand. The IUCN and New
Zealand status alike classify this species as Data Deficient due to limited information to assess
abundance and present decline (Baker et al. 2010; Hammond et al. 2008b).
Up until recently, common dolphins worldwide were considered to be one species (Delphinus
delphis). At least two distinct species are now known, the short beaked (D. delphis) and the long
beaked (D. capensis) (Heyning & Perrin, 1994; Rosel et al. 1994). Worldwide, the IUCN status
of D. delphis is that of Least Concern, based on widespread distribution and high abundance,
despite growing threats (Hammond et al. 2008c) D. capensis, however, is listed as Data
Deficient due to a lack of information on the number of incidental and deliberate takes
(Hammond et al. 2008d). In New Zealand waters, common dolphins are one of the most poorly
understood Delphinids, and are subject to a number of anthropogenic impacts including fisheries
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bycatch, pollution and tourism (Stockin et al. 2009a; Stockin & Orams, 2009). Although
currently listed as Not Threatened by the New Zealand threat classification system, a lack of
robust scientific data and consequently an uncertain taxonomic status, have lead to submissions
to reclassify this species as Data Deficient (Stockin & Orams, 2009).
Cetacean-Based Tourism
Whale watching (tours with at least some commercial aspect to see, swim-with or listen to any
species of whale, dolphin or porpoise) is a worldwide growing industry. Between 1991 and 2001
the number of countries involved in this industry expanded from 31 to 87, and the number of
communities worldwide grew from 200 in 1994 to 492 in 200l (Hoyt, 2001). The United States is
the worldwide leader in whale watching, with 38% of global whale watchers (O'Connor et al.
2009). New Zealand has 4% of global whale watchers, an estimate of 546,445 patrons (O'Connor
et al. 2009). Although this industry provides educational and economic benefits (Hoyt, 2001)
along with its growth, concerns about the impacts on the target species’ welfare and behaviour
are also expanding (Orams, 2004; Steckenreuter et al. 2011; Steckenreuter et al. 2012; Stockin et
al. 2008).
Cetacean watching in New Zealand remains an integral aspect of tourism and has been an
existing industry for more than twenty years. Over ten locations around the country in both the
North and South islands offer whale watching. Many of these include swim-with-dolphin
activities (O'Connor et al. 2009). A growing number of research studies have been undertaken in
New Zealand investigating cetacean biology, abundance, distribution, behaviour and influences
of tourism (Constantine et al. 2004; Merriman et al. 2009; Pearson, 2009; Rayment et al. 2011;
Rowe & Dawson, 2009; Stockin et al. 2009; Stockin et al. 2008). Queen Charlotte Sound is
frequented regularly by four dolphin species in addition to New Zealand fur seals (Arctocephalus
forsteri), and occasional passing killer whales (Orcinus orca), however, to date no baseline study
has been conducted in the use of this Sound by such species. Despite this, dolphin watching and
swimming activities have been in existence in the area since 1992.
Effect of Tourism on Cetaceans
A growing number of studies in New Zealand are being undertaken to examine the short and
long term influences that whale watching and tourism have upon targeted species. Bottlenose
dolphins in Milford Sound, NZ displayed changes in residency patterns in response to the
presence of tour boats in the region, suggesting long term implications for the population
(Lusseau, 2005). In the Bay of Islands, dolphins displayed increased avoidance to swimmers
over the course of a two year study (Constantine, 2001). Short term response in the form of
vessel avoidance by bottlenose dolphins has been observed in several studies in Milford and
Doubtful Sounds, as well as the Bay of Islands (Constantine et al. 2004; Lusseau, 2003b, 2004).
Furthermore, the Doubtful Sound population displayed an increase in diving time (Lusseau,
2003b) and socializing and resting were disrupted among the Doubtful and Milford Sound
populations (Lusseau, 2003a, 2004). Similar investigations have examined influences of tourism
on Hector’s dolphin populations. As the time of dolphin swim encounters increased, Hector’s
dolphins became disinterested or actively avoided tour boats (Bejder et al. 1999). In Akaroa
Harbour, increased tolerance to swimmers was displayed over time (Martinez et al. 2011).
Dolphins were shown to display a higher level of activity when auditory stimulants were utilized
during swim encounters (Martinez et al. 2011).
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Dusky dolphins in Kaikoura were exposed to the presence of vessels 72% of the time during
daylight hours (Barr & Slooten, 1999). They were found to swim more slowly, reorient more
often, change behavioural states more often and spend more time milling and travelling and less
time resting, in the presence of vessels. A more recent study indicates vessels in the presence of
dolphins 50% of the time. Milling time was further increased, while resting time further
decreased. In addition, an increase in the number of swim drops of shorter duration was found
over time (Lundquist, 2011). Groups of dolphins tended to tighten while leaping and porpoising
behaviour increased around vessels (Markowitz et al. 2009). In the Hauraki Gulf, common
dolphin foraging and resting periods were significantly impacted by the presence of tour boats,
causing concern over potential long term impact (Stockin et al. 2008). Boat avoidance was
observed by common dolphins in Mercury Bay, particularly in relation to smaller groups of
animals (Neumann & Orams, 2006).
Marine Mammal Regulations
The marine mammal protection regulations were updated in 1992 by the New Zealand
government to support the “protection, conservation, and management of marine mammals” by
aiming to regulate human contact and the behaviour of commercial operators. Regional
conservancies of the Department of Conservation in New Zealand issue permits to approach,
view and swim with dolphins. Additionally, opportunistic dolphin viewing permits are issued for
dolphins and seals and prohibits the deviation off course for such events (New Zealand
Government, 1992). A number of the regulations apply to the activity of commercial and tourism
vessels in the presence of cetaceans. Any outfit that is permitted to conduct whale watching
activities is required by law to abide by these and all established marine mammal protection
regulations.
Dolphin watching and swimming has been an existent tourist activity in QCS for approximately
twenty years. It is plausible to surmise that this activity may expand in the region, as consistent
with global trends of growth in the industry (Hoyt, 2001). Studies have indicated that vessel
based tourism has effects on cetaceans and may result in impacts including change in behaviour
and habitat use, or area avoidance (Constantine et al. 2004; Lusseau, 2004, 2005) and even
further biological alterations such as changes in breathing patterns (Hastie et al. 2003). Thus, the
present research that is being undertaken in Queen Charlotte Sound is critical. Since there is a
paucity of information on the dolphin distribution and utilization of the Sound as a habitat, any
further expansion in tourism within the region may potentially pose serious threats to
sustainability. Furthermore, the marine mammal regulations which are in place to protect marine
mammals, by limiting human activity and prescribing appropriate vessel behaviour (New
Zealand Government, 1992) must be examined for, the level of efficacy in accomplishing the
goals for which they were established.
Platforms of Opportunity for Data Collection
A ship of opportunity is a vessel used as a survey platform that is not chartered for this specific
purpose (Wall et al. 2006). Opportunistic platforms for marine mammal research can serve as
cost-effective tools for data collection in waters that may otherwise be unattainable due to
limited funding or inaccessibility (Wall et al. 2006; Williams et al. 2006). Cetacean research can
be conducted from a number of different types of opportunistic platforms. In the Bay of Biscay,
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the ferries have been utilized to conduct cetacean distribution, relative abundance and habitat
studies (Brereton et al. 1999; Kiszka et al. 2007). A large cruise ship was utilized in the North
Atlantic for a pilot study, offering insight into the diversity of marine mammal species in the area
(Compton et al. 2007). Furthermore, research vessels that are conducting other studies such as
groundfish surveys, geological studies or other mammal studies, can serve as excellent platforms
for distribution, habitat and prey studies (Moore et al. 2000; Palacios et al. 2012; Wall et al.
2006). Additionally, tour vessels have been used as a means of marine mammal data collection
(Martinez, 2010; Moura et al. 2012; Stockin et al. 2008; Wiseman et al. 2011). Although the
vessels primarily target dolphins and whales for the purposes of viewing, valuable data on
distribution, habitat and aspects of tourism can be garnered during marine mammal tours, as long
as the distribution of effort and potential biases of search methodology are accounted for.
Traditionally, cetacean biologists collect distribution and abundance data by designing linetransect surveys offering equal sampling probability in a study area (Buckland et al. 2001;
Williams et al. 2006). However, opportunistic platforms offering systematic and non-systematic
coverage of a study area, can serve as suitable alternatives. Platforms that allow for the collection
of cetacean sighting data along with physical oceanographic parameters can render interesting
scientific results, and offer particularly valuable ecological insight (Wall et al. 2006). In the
Hauraki Gulf, data leading to evidence of seasonal shifts in Bryde’s whale (Balaenoptera edeni)
distribution and corresponding temperature shifts were collected aboard a tour vessel (Wiseman
et al. 2011). Furthermore, in the Bay of Biscay, ferry-based cetacean surveys led to the detection
of habitat partitioning associated with bathymetric features for a number of cetaceans in the
region (Kiszka et al. 2007).
As such, this study is focused around the data collection from two types of opportunistic
platforms, systematic (Queen Charlotte Sound mailrun with fixed routes) and non-systematic
(dolphin tour vessel). Securing funding for dedicated distribution, abundance or habitat studies
can present obstacles (Williams et al. 2006). By utilizing vessels that are currently operational in
the region, access to the study site and focal species can be accomplished on a regular basis at a
minimal cost, and with no further environmental impact. Although sampling probability within
the study site is not uniform, the systematic opportunistic platform allows for near full coverage
of the Sound. The non-systematic platform offers survey time in which to assess dolphin group
dynamics, as well as data collection on aspects of the dolphin tourism industry within Queen
Charlotte Sound.
2. STUDY RATIONALE
Limited research on marine mammals has been conducted in the QCS. Merriman et al. (2009)
conducted a study on the abundance of bottlenose dolphins (Tursiops truncatus) in the greater
Marlborough Sounds region (41° S, 174° E) including Admiralty Bay, Pelorus Sound and Queen
Charlotte Sound. Approximately sixty percent of the survey effort conducted as part of this study
occurred within QCS. The study found that 211 (95% CI = 195 to 232) bottlenose dolphins
frequent the area per annum and form part of a larger coastal population based on photoidentification that indicated 335 uniquely marked individuals between 1992-2005. Other than the
Merriman et al. (2009) study, which solely investigated bottlenose dolphins and primarily
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assessed their movement across the Sounds, no other Delphinid research has been conducted in
QCS to date. Most studies have focused primarily on dusky dolphins in nearby Admiralty Bay
(Benoit-Bird et al. 2004; Markowitz et al. 2004; McFadden, 2003; Pearson, 2009). Thus,
significant information gaps exist for the Delphinid populations inhabiting QCS.
Queen Charlotte Sound is of particular interest because it is an area of high vessel traffic and
subject to a number of anthropogenic influences, including recreational boating, tourism, large
vessel traffic and marine farming (Markowitz et al. 2004). Picton marina (41° 17’31 S, 174° 0’
17 E) has the capacity to berth 232 vessels up to 35 m in length (Marinas in New Zealand, 2012),
and the adjacent Waikawa marina (41° 16’0 S, 174° 2’ 22 E), one of New Zealand’s largest
marinas, hosts 600 berths (Marlborough, 2012). Several water taxis, water activities and
recreational boaters operate frequently within the Sound (AA Tourism: Result for Activities in
Picton, 2012; Picton Water Taxis, 2012) in addition to two major tour boat companies
Dolphinwatch Ecotours, and Beachcomber cruises. Furthermore, QCS serves as the main ferry
terminus between the North and South Islands of New Zealand. Indeed, it is an important part of
the national transportation route for vessels between the two islands that has been used
throughout the 20th century. The frequent inter-island service began in 1962, with high speed
crafts introduced in 1994 (Parnell, et al. 2007). The two inter-island ferry companies that transit
Queen Charlotte Sound operate multiple times a day (Bluebridge, 2012; Interislander, 2012).
Several cruise liners operate within Queen Charlotte Sound and Picton Harbour, serving as a port
of call for various cruises (Port Marlborough Cruiseship Schedule, 2011). There are currently
six marine farm facilities operational in the region, two harvesting Greenshell mussels (Perna
caniculus) and four harvesting King (Chinook) Salmon (Oncorhynchus tshawytscha). New
Zealand King Salmon have further proposed to establish an additional eight farms within the area
of the Marlborough Sounds, three of which are planned for Queen Charlotte Sound and Tory
Channel (Davidson et al., 2011; New Zealand's King Salmon Proposal, 2012).
Thus, the Queen Charlotte Sound serves an integral role in the local communities for transport,
tourism, local business and recreation. No scientific study to date has examined the fine scale
distribution, habitat, and aspects of tourism and conservation of Delphinids within the Sound. It
is critical to establish, from this point on, a baseline of data to begin to understand where and
how the dolphins are utilizing Queen Charlotte Sound. Such findings can be considered and
incorporated in future management decisions that benefit the needs of the local community. In a
region that is heavily utilized, it is important to consider the impact on sensitive dolphin
populations, to ensure their long-term use of the Sound.
The impetus for commencing research within Queen Charlotte Sound was the proposed
expansion of permitting among the present regional tourism industry and concern about species
conservation. Bottlenose and Hector’s dolphins maintain a nationally endangered status and New
Zealand bottlenose are on the decline (Baker et al. 2010; Currey et al. 2009; Tezanos-Pinto et al.
in press). Common dolphins remain largely unstudied from an abundance perspective, with their
conservation and taxonomic status considered in flux (Stockin & Orams, 2009), while dusky
dolphins are considered data deficient (Baker et al. 2010). Furthermore, New Zealand killer
whales (type A), are critically endangered, based on population size (Baker et al., 2010). New
Zealand fur seal rookeries are present in the nearby in Cook Strait. Their numbers are on the rise
after being historically hunted to local extinction (Taylor et al., 1995). These factors cause
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concern, and present an urgent need for information in an area that remains only minimally
studied. Thus, data collection at present is critical in four core areas:




Delphinid occurrence and distribution
Marine mammal density
Marine mammal habitat features and group dynamics
Tourism and anthropogenic use of the Sound
The results of this study will lead to an understanding of the significance of the Sound as a
marine mammal habitat while bridging fundamental gaps in current knowledge about these
species locally as well as compared within a broader NZ context. This is critical given regional
differences between populations are evident within and beyond NZ waters. It will provide a
foundation of information on which future management decisions can be based. Consulting such
data prior to continued growth of tourism or industry can minimize potential threats to already
sensitive species and contribute to a sound management plan.
3. RESEARCH QUESTIONS
Occurrence and Distribution
Queen Charlotte Sound: Patterns in distribution of five delphinids
(data source: Dolphinwatch trips from 1999 to 2010 (historical) and 2011-2014 (current)
Is the occurrence of bottlenose, Hector’s, dusky, common dolphins and orca affected temporally?
Are patterns in occurrence affected by time of day, month, season, year?
-Is there evidence of frequent/infrequent usage of the Sound?
Is the spatial distribution of bottlenose, Hector’s, dusky, common dolphins and orca affected
temporally? Are patterns in spatial distribution affected by time of day, month, season, year?
-Is there evidence of site specific species distribution?
-If so, does this change over time?
Is the spatial distribution of bottlenose, Hector’s, dusky, common dolphins and orca affected by
tidal state (ebb/flow)?
Density
Marine mammal density estimates from a systematic and non-systematic opportunistic
platform
Are there spatial patterns in marine mammal density?
Are there temporal patterns in marine mammal density? monthly? seasonal? annual?
How do marine mammal species’ density estimates compare between platform type
(systematic/non-systematic)
Is there temporal variation in fur seal density estimates in the presence of a salmon farm?
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Delphinid habitat features and group dynamics
The physical structure of the Sound: A region defined by low variation in physical parameters
(pending)
data source: Marlborough District Council monthly CTD (temperature and conductivity data)
2011-2013
What are the physical, biological and anthropogenic characteristics associated with species
distribution?
 Physical: SST, depth, salinity, distance from shore, tidal ebb/flow
 Biological: mammals (interspecific /conspecific), birds, fish
 Anthropogenic: Vessels (recreational/commercial; ferry); marine farms
Group Dynamics
How do group composition and group size vary amongst species?
Are there temporal or spatial patterns in group composition and group size?
Distribution of Behaviour
Are there temporal patterns in the distribution of behaviour?
Are there spatial patterns in the distribution of behaviour?
How does distribution of behaviour compare between species?
Anthropogenic features and aspects of tourism in Queen Charlotte Sound
Anthropogenic presence in Queen Charlotte Sound
What is the current level of anthropogenic influence in Queen Charlotte Sound?
Marine Farms:
What is the current level of marine farm presence? What is the
size/capacity/output of the farms?
What is the spatial location of the marine farms?
Ferry:
What is the frequency of ferry passage through the Sound?
How does this vary temporally?
What is the spatial path that the ferry takes through the Sound?
Vessels: Is there temporal variation in the vessel usage of QCS?
Are there locations or time periods where high vessel activity is observed amongst
dolphin groups?
Tourism
Swim-with-dolphin operational characteristics
During what percentage of trips do swim encounters take place? Per season? Per month?
During what percentage of trips do swims occur with bottlenose? commons? duskys?
What is the average number of swimmers per trip?
What is the average number of drops per trip?
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Time
What is the average length of swim encounters?
with bottlenose? commons? duskys?
What is the average length of time of swim drops?
with bottlenose? commons? duskys?
What is the average length of time that dolphins are present amongst swimmers (25 m)?
does this vary on successive drops?
does this vary with the number of swimmers in the water?
does this vary with group cohesiveness?
Behaviour
What is the behaviour of dolphins during initial approach, on successive swim drops and after
swims?
Does behavioural state change before and after a swim drop?
Is a change in behavioural state more likely with a certain behavioural states?
Does group cohesion change post swims?
Reactions
What are dolphins’ reactions to swimmers in QCS? bottlenose? common? dusky?
Do reactions vary with the distance from dolphins when placed in water?
Do reactions vary with the distance the vessel stops upon approach?
Do reactions vary with the swimmer placement in water?
Do reactions vary with group cohesion?
Do reactions vary with group (subgroup) size?
4. METHODOLOGY
Study Area
The Marlborough Sounds, located on the northeastern tip of the South Island of New Zealand,
including its inlets and estuaries, has a coastline of approximately 1,772 km (Davidson et al.
2011). The easternmost area of the sounds and study site, Queen Charlotte Sound (Figure 5), has
a convoluted shoreline consisting of two large inlets, about 20 large bays, and many smaller
coves. The Sound, including Tory Channel, has a total of 404 km of coastline (Davidson, et al.,
2011). The primary survey areas include the main channel of Queen Charlotte Sound, Tory
Channel, and the two main inlets, Endeavour Inlet and East Bay. Survey effort varies and
depends on the tracks taken by two opportunistic vessels.
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Figure 5. Map of Queen Charlotte Sound study site indicating Tory Channel, and the major inlets and
harbours
Research Platforms
Studies are conducted aboard two opportunistic platforms. Delphinus (Figure 6a), owned by
Dolphin Watch Ecotours, is a 13m catamaran powered by two 220-horsepower John Deer
inboard engines, with a viewing height of 2.4 m, that operates dolphin swims and ecotours in
Queen Charlotte Sound. Tiricat (Figure 6b), owned by Beachcomber cruises, is a 13m catamaran
powered by two 300-horsepower John Deer inboard engines, with a viewing height of 2.5m, that
operates mail delivery as well as scenic tours throughout the Sound.
(a)
(b)
Surveys
Opportunistic/Non-Systematic
Figure 6: Opportunistic platforms a. Delphinus b. Tiricat
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Surveys of Queen Charlotte Sound are conducted aboard the opportunistic platform Delphinus.
The vessel runs one morning trip for viewing and swimming with dolphins within the Queen
Charlotte Sound during austral spring (October-November), summer (December-February), and
autumn (March-April). The daily route varies and is dependent upon the previous days’
sightings, calls from other operators indicating the presence of dolphins and the travel required to
locate a group of dolphins (all biases to be accounted for in analyses). Delphinus travels at an
average speed of 18 knots, however, the vessel makes a number of stops throughout the Sound
when searching for dolphins, at which time observers perform 360 degree searches with both
binoculars and naked eye.
Search Methodology
Visual surveys are conducted with the naked eye and 7x50 Bushnell binoculars by the main
observer and at least one other trained observer using continual scanning protocol in a 180
degree area from the bow (Mann, 1999). “On-effort” surveys (periods of active searching for
marine mammals) commence once the boat departs from the harbour and continue until harbour
re-entry. Weather and sighting conditions (cloud cover, glare, visibility, Beaufort Sea state and
swell) are continually assessed and updated throughout the survey. Search effort is changed to
“off-effort” in periods of rain, Beaufort Sea state > 3, and glare >50% field of view. Visual cues
such as marine mammal fins breaking the surface, splashing, blows and the presence of boats or
seabirds, such as Australasian gannets (Morus serrator) and shearwaters (Puffinus spp.), which
have been known to associate with the focal species, are used to help find marine mammals
(Stockin et al. 2008; Vaughn et al. 2007). Occasionally, other vessels call with reports of the
location of dolphins. When the vessel stops, observers continually scan 360 degrees with the
naked eye or binoculars in search of animals (Mann, 1999).
Opportunistic/Systematic
Tiricat operates six days a week, year-round on three separate routes that collectively enter all
the major inlets and bays, offering near complete coverage of Queen Charlotte Sound, with the
exception of the inner Sound (Grove Arm) (Figure 7). The different survey routes are established
according to the day of the week. Tiricat operates at an average speed of 19 knots, and performs
numerous stops throughout the Sound for mail delivery and passenger pickup and drop off within
the Sound.
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Search Methodology
Figure 7. Survey Routes taken by Tiricat through the Queen Charlotte Sound and Tory
Channel
Visual surveys are conducted with the naked eye by the main observer using a continual
scanning protocol in a 180 degree area from the bow (Mann, 1999). “On-effort” surveys
commence once the boat departs from the harbour and conclude upon harbour re-entry. Visual
cues such as marine mammal fins breaking the surface, splashing, blows and the presence of
boats, or seabirds, such as Australasian gannets and shearwaters are used to help find marine
mammals (Stockin et al. 2008; Vaughn et al. 2007). When the vessel stops for extended periods,
the observer suspends search effort.
Marine Mammal Sighting and Location Data Collection
Once a group of marine mammals is sighted, a GPS waypoint is recorded with a GARMIN etrex
20, the estimated distance and angle to the group is recorded and the survey changes to “offeffort” mode. Prior to the vessel approaching the dolphins, the main observer assesses the initial
group behaviour. This is accomplished via scan sampling, a technique in which the observer
records an individual’s instantaneous behavioural state before moving on to the next animal
(Altmann, 1974). The group activity is determined by the predominant behaviour (the
instantaneous assessment of >50% of the group) (Mann, 1999). A group is defined as any
number of animals in apparent association, moving in the same direction and likely involved in
the same behaviour (Shane, 1990; Wells et al. 1980). Dolphins may alternate group structure by
fission fusion (breaking into smaller subgroups and then re-coalescing into the larger pod). Small
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subgroups are considered to be a part of the entire large group from which they originate (Defran
& Weller, 1999). Dolphin group behaviour is determined using the following categories, which
are modelled on those described by Constantine (2002) and Shane et al. (1986):





travelling: persistent directional movement as a group;
foraging: dolphins observed diving deeply, and rapidly circling; prey sometimes
observed;
socializing: displays of mating, playing, rubbing, chasing or leaping;
milling: frequent change in direction, no apparent forward motion, animals surfacing in
multiple directions;
resting: animals involved in slow movements as a tightly cohesive group (less than one
body length); animals are often stationary, and observed barely breaking the surface.
At the closest approach to the dolphins, another GPS waypoint, and bottom depth are recorded.
Sea surface temperature (SST) (°C), salinity (ppt) and conductivity (mS) values are recorded at
each sighting using a YSI 85 temperature, salinity and conductivity meter. Visual assessment of
the group is conducted to determine species, group size, group cohesiveness and social group
composition.
Group size is recorded as:
 the minimum number of animals likely to be in the group
 the best estimate of animals in the group
 the absolute maximum number likely to be in the group
Group cohesiveness was categorized based on Shane (1990):
 tight: 1-2 dolphin lengths apart
 loose: 3-5 dolphin lengths apart
 dispersed: greater than 5 dolphin lengths apart
Age structure of the group is classified as:
 calves: animals that are frequently observed in close association with an adult, and
approximately half the size of a full grown adult (Fertl, 1994; Mann & Smuts, 1999)
 neonates: animals that are observed in close association with an adult, with dorso-ventral
foetal folds (up to about 3 months) and uncoordinated behaviour (Mann & Smuts, 1999)
 Adults: full grown independent animals; not included in the other categories
The sighting area is scanned for the presence of other marine mammal groups (cetaceans; fur
seals) within 300m of the vessel using a naked eye search. If marine mammals are present, they
are recorded as “off -effort” sightings. Some sightings are only viewed and assessed in passing
since Beachcomber cruises hold an opportunistic permit and thus cannot deviate off course for
marine mammal viewing. Additionally, the vessel does not stop to view marine mammals if time
does not allow.
Upon passing through the vicinity of a salmon farm a start and stop waypoint are recorded. The
number of fur seals present in the area is quantified and the activity is noted and classified as
 Swimming: present or moving through water
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Feeding: actively consuming prey items
Hauled on rocks
Hauled on artificial structure
Anthropogenic Activity
The number of vessels within 300m of the group is recorded upon initial vessel approach and the
maximum number of vessels present during the encounter is recorded (New Zealand
Government, 1992). Additionally, the number of ferry passes within 300m of a dolphin group
during a sighting are recorded and it is indicated if the initial sighting is in the presence of a
marine farm. Recreational and commercial vessel activity is quantified on a daily basis at the
harbour entrance and in bays that are frequented regularly on the mailrun to assess changes in
vessel traffic.
Operational Characteristics of a Fully Permitted Dolphin Tour Vessel
The operational activities of dolphin swim tourism are assessed from the tour boat. Swim
encounters are observed from the top of the vessel, where an unimpeded view of swim activities
is made possible. A swim encounter is marked by the time the group is initially approached until
the group departs or the vessel departs the group (Scarpaci et al. 2003).
The following parameters are measured during the swim encounter:
 Species, group size and group composition;
 Vessel approach methods;
 Distance from the dolphins when swimmers are placed in the water;
 Swimmer entrance in the water;
 Number of swim drops;
 Number of swimmers per drop;
 The length of swim attempts and proportion of time that dolphins are amongst swimmers.
Swimmer Placement
Swimmer entrance in the water is assessed and determined, similar to (Constantine, 2001).
 Side and ahead: the group is placed alongside and slightly ahead of the group of dolphins
 In path: swimmers are placed in the direction of the path of the dolphins travel
 Amongst group: swimmers are placed in the vicinity (within 300 m) of a group of
dolphins, travelling in no particular direction
A GPS waypoint is taken when swimmers enter the water and a waypoint is recorded when the
swim is called off by a staff member. This time was selected rather than the time when
swimmers actually get back on the boat (Martinez et al. 20011; Markowitz et al. 2009) for
consistency purposes. Indeed, sometimes the distance of the boat from the swimmers or
prevailing weather conditions require more time for swimmers to exit the water and at the end of
some of the swims, swimmers remain in the water for the crew to take a group photo. The swims
are usually terminated if the dolphins do not swim through the group, or when animals swim past
the vessel. A stopwatch is started when and if the dolphins come within 25 m of the swimmers
and remains running until all the animals leave this distance, to express the proportion of the
swim time that the animals are present amongst swimmers (Martinez, 2010).
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Dolphin Behaviour and Reactions:
A scan sample of the predominant group behaviour (Altmann, 1974; Mann, 1999) is completed
after each approach, within 100 m of the group (Martinez, 2010) and before swimmer entrance in
the water (unless they enter the water beyond 100m). Dolphin reactions are measured based on
the response of at least 50% of the group (Mann, 1999) to the presence of the swimmers and
vessel. The reactions are classified based on adaptations from Neumann & Orams (2005) and
Martinez (2010):
 Attraction: defined as at least 50% of the group changing direction and moving toward
the vessel and swimmers;
 Avoidance: defined as at least 50% of the group changing their direction of travel away
from the vessel or swimmer, diving, or approaching another boat;
 Neutral: defined as the group maintaining its course of travel or behaviour in the presence
of the vessel and swimmers.
If dolphins swim through a group of swimmers when the swimmers and vessel are in the path of
travel of the animals, the response is still considered neutral. Interactions between swimmers and
dolphins that are visible at the surface are recorded. An interaction is defined as at least one
dolphin actively approaching and/or swimming amongst a swimmer within 5m (Constantine,
2001). The number of individual animals displaying an interaction is noted even when the
majority of the group displayed neutral or avoidance behaviour. Similarly, individuals that
display avoidance behaviour when within 5m of swimmers are also recorded.
Photo-Identification
During dolphin viewing events, images of dolphin dorsal fins are taken using a Nikon D90 SLR
camera fitted with an autofocus adjustable 70-300 mm lens. Photographs will be evaluated and
graded “excellent”, “good” and “poor” based on fin angle, contrast and focus (Slooten et al.
1992).
Data Analysis
Spatial analysis will be conducted in ArcGIS. Sightings will be summarized in a 1km grid
across the survey area and density estimates will be calculated in terms of the number of
sightings and animals encountered per minute and hour.
Individually marked fin photographs will be catalogued and the median resight rate will be used
to estimate exposure of individual animals to swim tourism in order to assess potential for
cumulative effects on known individuals (Constantine, 2002).
5. SIGNIFICANCE OF THE STUDY AND EXPECTED OUTCOMES
This study is significant in that it will result in baseline scientific data on marine mammal species
distribution, habitat, and anthropogenic influence including exposure to swim tourism within the
Queen Charlotte Sound. Management recommendations based on the findings of the study will
be offered to the Department of Conservation in relation to:
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The stakeholder usage of Queen Charlotte Sound with consideration given to the
established regions and periods of dolphin high use
Restricted use of the Sound in regions of dolphin high use, and in time periods and areas
where calving, resting or foraging activities may predominate
Current and future tourism activity on dolphin populations within the Sound and
suggestions for potential amendments to dolphin tourism permitting and Marine
Mammal Regulations
Suggestions for further studies that branch from the present research
Outcomes of the Study:
1) A PhD Thesis entitled: “Queen Charlotte Sound: A habitat for marine mammals”
2) A report to be submitted to the Department of Conservation (January 2013) providing
updates on the progress and status of the ensuing research
3) At least three peer-reviewed scientific publications in international journals:
 Occurrence and distribution of Delphinids in Queen Charlotte Sound, NZ
 Marine mammal density estimates in Queen Charlotte Sound, NZ
 Queen Charlotte Sound as a marine mammal habitat: Delphinid habitat associations,
group dynamics and distribution of behaviour
 An assessment of anthropogenic use and dolphin tourism activities in Queen Charlotte
Sound, NZ
4) Contribution to the established photo-ID catalogue for the Marlborough Sounds bottlenose
dolphins
5) Data presentation at international conferences including the Society for Marine Mammalogy
Conference held in Dunedin, NZ in 2013
6. SUMMARY OF PRELIMINARY RESULTS
A total of 164 surveys have been completed thus far on both vessels between November 2011
and August 2012 (Delphinus n=76 and Tiricat, n=88). The number of monthly surveys on
Delphinus ranged from 7-17. The number of monthly surveys on Tiricat ranged from 6-20.
Dolphin Sightings
Delphinus
A total of 153 sightings were observed on Delphinus between November 2011 and April 2012.
Hector’s dolphins were the most commonly observed species accounting for 49% of sightings
(n=73) followed by bottlenose dolphins (39%; n=57) dusky dolphins (6%; n=7) common
dolphins (5%; n=6), and 2 unidentified dolphin sightings (1%) (Table 1).
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Table1. Total number of dolphin sightings aboard Delphinus from November 2011 to April 2012
Species
No. of Sightings
Hector’s
73
Bottlenose
57
Dusky
9
Common
7
Unidentified Dolphins
2
SIGHTINGS
Hector’s dolphins were observed during all months of observation. The highest number of
sightings were observed in February (n=24), and March (n=18). Bottlenose dolphins were also
observed during every month with the highest number of sightings in April (n=18) and January
(n =16). Dusky and common dolphins were observed infrequently between November and
February (Figure 8).
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Bottlenose
Hector's
Dusky
Common
Unidentified
November December
January
February
March
April
MONTH
Figure 8. Monthly dolphin sightings aboard Delphinus from November 2011 to April 2012
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Tiricat
A total of 79 Delphinid sightings were observed aboard Tiricat between January and August.
Bottlenose dolphins were the most commonly observed species accounting for 49% of sightings
(n=39), followed by Hector’s dolphins (27%; n=21), dusky dolphins (8%; n=6), common
dolphins and humpback whales (1%; n=1 each) and 6 unidentified sightings (14%) (Table 2).
Table 2. Total number of dolphin sightings aboard Tiricat from November 2011 to April 2012
Species
No. of Sightings
Bottlenose
39
Hector’s
21
Dusky
6
Common
1
Unidentified Dolphins
11
Bottlenose dolphins were observed during all months of the study thus far, with the highest
number of sightings in May and June (n=10). Hector’s dolphins were observed from January to
June and the highest numbers were in March and April (n=6, n=5). Dusky dolphins were
observed from May to August. A humpback group was observed in July and a group of common
dolphins was observed in March (Figure 9).
12
Bottlenose
Hector's
Dusky
Common
Unidentified
SIGHTINGS
10
8
6
4
2
0
J
ua
an
ry
a
ru
b
Fe
ry
M
ch
ar
ril
Ap
M
ay
ne
Ju
ly
Ju
MONTH
Figure 9. Monthly dolphin sightings aboard Tiricat from January to August 2012
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s
gu
u
A
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Group Dynamics
Group Size
Bottlenose dolphins ranged in group size from 1 to 70 animals. Monthly average group size
ranged from 15 to 36 animals. Hector’s dolphin group size ranged from 1 to12 animals and the
monthly average group size ranged from 1 to 4 animals. Dusky dolphin group size ranged from 3
to15 animals, with monthly average group size from 5 to11 animals. Common dolphins were
observed in groups of 7 to14 animals (Figure 10).
80
Bottlenose
Hector's
Dusky
Common
70
GROUP SIZE
60
50
40
30
20
10
ug
us
t
A
Ju
ly
Ju
ne
ay
M
pr
il
A
ar
ch
M
y
Fe
br
ua
ry
Ja
nu
ar
ec
em
be
r
D
N
ov
em
be
r
0
MONTH
Figure 10. Average monthly group size of dolphin sightings within Queen Charlotte Sound
aboard Delphinus and Tiricat. Error bars represent group size range.
Group Composition
Bottlenose, common and dusky dolphins were frequently observed with calves (20% of
sightings, n= 24; 37% n=6; and 75%, n= 6; respectively), and bottlenose were frequently
observed with neonates in the group (34% of sightings, n=40) (Figure 11). Bottlenose calves
were present all year long. Neonates were present from December to June with peaks observed in
January and February (Figure 12). Hector’s Calves were observed from February-April and
neonates were observed in February. Dusky calves were present in groups observed in
November, December and July. Calves were observed in groups of common dolphins observed
in November and February.
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Percentage
80
70
% Of Sightings With Calves
60
% Of Sightings With Neonates
% Of Sightings With Both
50
40
30
20
10
0
Bottlenose
Hector's
Dusky
Common
Species
Figure 11. Percentage of dolphin sightings by species observed with calves, neonates
and both
Number Of Groups
20
18
Bottlenose Total Groups
16
Bottlenose Groups w. Calves
14
Bottlenose Groups w. Neonates
12
10
8
6
4
2
us
t
Au
g
Ju
ly
e
Ju
n
ay
M
Ap
ril
ar
ch
M
ar
y
Fe
br
u
ry
Ja
nu
a
be
r
De
ce
m
No
ve
m
be
r
0
Month
Figure 12. Monthly distribution of the presence of calves and neonates among bottlenose dolphin
groups
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Initial behaviour
Bottlenose dolphins were primarily observed travelling, milling and foraging. Hector’s were
observed milling the majority of the time. Common dolphins were resting in the majority of
initial encounters, and dusky dolphins were frequently foraging (Figure 13).
Hector's Dolphin Initial Behaviour
Bottlenose Dolphin Initial Behaviour
25%
11%
28%
13%
4%
5%
traveling
traveling
resting
resting
milling
milling
socializing
socializing
foraging
15%
72%
27%
Dusky Dolphin Initial Behaviour
Common Dolphin Initial Behaviour
11%
29%
traveling
resting
22%
resting
milling
foraging
foraging
57%
67%
14%
Swim13.
Encounters
Figure
Distribution of dolphin species initial behaviour
From November to April there were 74 survey days in which sightings occurred. Of these, a total
of 51 swim encounters were observed. Thus, during 69% of survey days with sightings, swim
encounters took place. During the majority of the time that swim encounters did not occur, it was
because sightings were Hector’s dolphins. On two occasions, the animals were sighted and then
lost and on two occasions the group was deemed too small to swim with (a solitary animal, or
group of a few individuals). On one occasion it was due to feeding behaviour.
The majority of swim events (n=40, 78%) during the season took place with bottlenose dolphins.
Swim events occurred with common dolphins (n= 5), 10% of the time, dusky dolphins (n= 3),
4% of the time, dusky and Hector’s mixed groups (n=2), 4% of the time and with fur seals (upon
not seeing dolphins) (n = 1), 2% of the time (Figure 14).
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6%
4%
2%
10%
78%
Bottlenose
Common
Dusky
Dusky/Hector's
Fur Seals
Figure 14. Percentage of dolphin swim encounters by species
Dolphin Behaviour
Three swim events with common dolphins as well as dusky dolphins were assessed. On all three
occasions, common dolphin initial behaviour was resting. Dusky dolphins were foraging on two
occasions, and initial behaviour was unknown on the third. Thirty eight bottlenose dolphin swim
events were assessed for behaviour. Milling and travelling were the initial behaviour nine times,
foraging seven times, resting six times, socializing four times and the initial behaviour was
unknown twice. Travelling was the predominate behaviour observed prior to successive swim
attempts with bottlenose dolphins (Figure 15).
30
Foraging
Resting
Traveling
Socializing
Milling
Unknown
Number
25
20
15
10
5
0
Initial
Approach
Attempt 1
Attempt 2
Attempt 3
Attempt 4
Behaviour At Each Approach
Figure 15. Bottlenose dolphin behaviour prior to swim encounters
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Further data processing and analyses will ensue in the coming months.
7.
PROPOSED TIMELINE AND SCHEDULE
Year 1: October 2011-October 2012
 Fieldwork commencement and development of field methodology;
 Preparation of literature review on focal species;
 Established working relationship with two local operators to secure data collection;
 Preparation of funding proposal to the Department of Conservation
 Continuation of field work and data collection;
 Commence data processing and analysis;
 Submit summary report to DOC;
 Preparation for Society for Marine Mammalogy Conference attendance and presentation.
 Data collection (through April);
 Data analysis;
 Presentation at SMM conference.
 Data analysis;
 Publication writing;
 Thesis write-up and completion.
8. REFERENCES
AA Tourism: Result for Activities in Picton. (2012). Retrieved 14 September, 2012, 2012, from
http://www.aatravel.co.nz/new-zealand/Picton_Activities.html.
Altmann, J. (1974). Observational Study of Behavior: Sampling Methods. Behaviour, 49(3/4),
227-267.
Azzellino, A., Gaspari, S., Airoldi, S., & Nani, B. (2008). Habitat use and preferences of
cetaceans along the continental slope and the adjacent pelagic waters in the western
Ligurian Sea. Deep-Sea Research Part I-Oceanographic Research Papers, 55(3), 296323. doi: 10.1016/j.dsr.2007.11.006.
Baker, A. N., Smith, A. N. H., & Pichler, F. B. (2002). Geographical variation in Hector's
dolphin: Recognition of new subspecies ofCephalorhynchus hectori. Journal of the Royal
Society of New Zealand, 32(4), 713-727. doi: 10.1080/03014223.2002.9517717.
Baker, C. S., Chilvers, B. L., Constantine, R., DuFresne, S., Mattlin, R. H., van Helden, A., &
Hitchmough, R. (2010). Conservation status of New Zealand marine mammals
(suborders Cetacea and Pinnipedia), 2009. [Article]. New Zealand Journal of Marine and
Freshwater Research, 44(2), 101-+. doi: 10.1080/00288330.2010.482970.
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Ballance, L. T., Pitman, R. L., & Fiedler, P. C. (2006). Oceanographic influences on seabirds and
cetaceans of the eastern tropical Pacific: A review. Progress in Oceanography, 69(2-4),
360-390. doi: 10.1016/j.pocean.2006.03.013.
Barr, K., & Slooten, E. (1999). Effects of toursim on dusky dolphins at Kaikoura. Wellington,
NZ.
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Queen Charlotte Sound, New Zealand - E

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