Non-native Survey Report 2005

Non-Native Fish Species Survey
Using Boat Electro-fishing in the
Spey and Dee Catchments
R. Laughton*, A. Hudson** and N. Sherwood***
Spey Research Report 03/06
*Spey Research Trust, 1 Nether Borlum Cottage, Knockando,
Morayshire AB38 7SD. Tel 01340810841, Fax 01340 810842, email
[email protected]
**Dee District Fishery Board, Mill of Dinnet, Dinnet, Aboyne, AB34 5LA.
Tel 01339 885241
*** Stellar Environmental, 1 Main Street, Aystone, Oakham, Rutland, LE15 9AE.
Tel 01572 821810
Prepared for
Cairngorms National Park Authority
Grantown on Spey
Morayshire
March 2006
CONTENTS
Page
List of Tables
3
List of Figures
3
Summary
5
Objectives
6
1 Introduction
7
3 Method
7
3 Results
9
3.1 Skating Pond, Grantown
3.2 Nethy Pool - Frankies Corner, Mainstem Spey
3.3 Loch Beag and the Bogach
3.4 Loch Alvie Angling Record
3.5 Lochs Davan and Kinord
4 Conclusions and Recommendations
9
13
13
17
17
22
5 Summary of Recommendations
27
Acknowledgements
28
References
29
2
LIST OF TABLES
Table 1: The fish species caught and catch per unit effort (fish.min-1) in the Skating Pond
Grantown, 29th May 2005.
Table 2: The fish species caught and catch per unit effort (fish.min-1) in Loch Beag and
the Bogach 30th May 2005.
Table 3: The fish species caught and catch per unit effort (fish.min-1) in Lochs Davan and
Kinord.
LIST OF FIGURES
Figure 1: Boat electro-fishing team from Stellar Environmental in action on Loch Beag,
May 2005. (Photo R. Laughton)
Figure 2: Aerial view of the Skating Pond in Grantown on Spey showing proximity to the
River Spey. (Photo R. Laughton)
Figure 3: Length (mm) frequency for trout caught in the Skating Pond, Grantown, 29 May
2005.
Figure 4: Length (mm) frequency distribution for eels caught in the Skating Pond,
Grantown, May 2005.
Figure 5: Orfe in natural colours (above) and Golden Orfe (below) captured in Skating
Pond, Grantown, 29th May 2005. (Photo R. Laughton)
Figure 6: Juvenile Tench captured in Skating Pond, Grantown, 29th May 2005. (Photo R.
Laughton)
Figure 7: Map showing locations of Loch Beag and Bogach.
Figure 8: Large Tench (8lb) captured in Loch Beag, May 2005. (Photo R. Laughton)
Figure 9: Roach and Rudd fry captured from Loch Beag Survey May 2005. (Photo R.
Laughton)
Figure 10a: Length (mm) frequency histogram for pike captured in Loch Beag and the
Bogach, 30th May 2005.
Figure 10b: Length (mm) frequency histogram for eels caught in Loch Beag and the
Bogach, 30th May 2005.
3
Figure 11: Orfe captured by an angler in Loch Alvie, 19th July 2005. (Photo K. Taylor)
Figure 12: Map showing location of Lochs Davan and Kinord on Deeside.
Figure 13a: Length frequency distribution for Perch in Loch Davan, 1st June 2005.
Figure 13b: Length frequency distribution for Pike in Loch Davan, 1st June 2005. Age
classes are estimated using Treasurer and Owen (1991).
Figure 13c: Length frequency distribution for eels in Loch Davan, 1st June 2005.
Figure 14a: Length (mm) frequency distribution for Perch captured in Loch Kinord, 31st
May 2005.
Figure 14b: Length (mm) frequency distribution for Pike captured in Loch Kinord, 31st
May 2005. Age classes are estimated using Treasurer and Owen (1991).
Figure 14c: Length (mm) frequency distribution for Eels caught in Loch Kinord, 31st May
2005.
4
SUMMARY
A previous survey using gill nets, angling and fish traps of lochs in Speyside and
Deeside (Redgewell, Laughton and Hudson 2004) indicated the presence of non native
species at a number of locations. This survey builds on the 2004 one by testing boat
electro-fishing as an approach to assess open water areas. The boat electrofishing was
trialled at five stillwater locations, Skating Pond (Grantown), Loch Beag, the Bogach, on
Speyside and Loch Davan and Loch Kinord on Deeside. A trial was also conducted on a
slow flowing reach of the Spey near the confluence with the River Nethy.
In general the technique proved successful with a range of fish species captured and a
range of age classes for the dominant fish species. Pike, eels, trout and perch were
captured. Non native species including Orfe (Leuciscus idus), (in Golden and natural
forms) and tench (Tinca tinca) were captured in the Skating Pond, rudd (Scardinius
erythrophthalmus) and roach (Rutilus rutilus) were captured in Loch Beag and an angler
provided another Orfe from Loch Alvie. No non-natives were captured from the Bogach,
Lochs Davan and Kinord.
Results from Loch Beag indicate that Roach and Rudd are establishing a spawning
population and the juvenile tench captured in the Skating Pond may also indicate a
spawning population. The benefits of the boat based electrofishing technique are
discussed along with the implications of non natives on the native fish populations.
5
OBJECTIVES
The objectives for the non-native fish species survey were to:
•
Test boat electro-fishing as a technique for surveying lochs, ponds and mainstem
stretches within the Dee and Spey catchments.
•
Produce baseline non-native fish species presence/absence data for key lochs
within the Spey and Dee catchments.
6
1.
INTRODUCTION
Redgewell, Laughton and Hudson (2004) carried out a survey of several lochs on
Speyside and Deeside during 2004. A questionnaire survey was used to examine fishing
pressures and techniques and gill netting was then used to examine if any non native
fish species were present. Encouragingly most of the lochs contained only the expected
range of species, typically, trout, pike, eels, and charr. However, non-native fish species
were discovered in Loch Beag, Speyside, adult rudd (Scardinius erythrophthalmus) and
roach (Rutilus rutilus) were captured but no juveniles. A number of ponds were also
examined and a variety of species were documented with breeding populations of
Golden Orfe, Leuciscus idus, present in one.
A number of techniques were implemented during the survey including gill-netting,
angling, minnow traps and electro-fishing along the margins. During the survey concern
was raised regarding the gill netting as suitable means for surveys. NORDIC protocols
were followed throughout and only small numbers of fish were caught however, the
authors felt that it would be useful to try alternatives and this survey explores boat based
electro-fishing.
2.
METHODS
Stellar Environmental, Rutland, were contracted to conduct boat electro-fishing surveys.
Electro-fishing equipment consisted of 13.4kVa generator linked to a transformer and
control box (Electracatch Model WFC4-HV) with two anodes and cathode. The anodes
were stainless steel rings (diameter 400mm) and were fitted with knotless mesh nets
(mesh size 2mm). Voltages ranged from 200V to 600V and ampage from 8A to 30A.
Two boats strapped provided a stable working platform. The electrofishing equipment
was placed in one boat and holding tanks in the other. Anode operators were stationed
at the front of each boat, while the driver was located at the rear of the boat containing
the electro-fishing gear. There was also room for an addition net handler. The paired
boats were powered by an outboard motor.
7
A simple sampling strategy was devised for the ponds and lochs. Each habitat area i.e.
reed beds, open water, shallow margins were fished and a note of the time fishing was
recorded. In general and since the main purpose of this survey was to determine species
present the data was then amalgamated from each habitat type. A fish finder was also
used in the larger lochs to identify potential accumulations of fish.
Sampling was conducted while the boat was moving forward with the anode operators
sweeping ahead of the bow. An additional crew member also caught any fish missed by
the anode operator. Fish were captured by the anodes with nets, on capture the anode
was switched off and the fish placed directly into the holding tanks. Fish were not
removed by hand from the anode and net to minimise risks to operators.
Figure 1: Boat electro-fishing team from Stellar Environmental in action on Loch
Beag, May 2005. (Photo R. Laughton)
After the survey was complete the fish were processed on shore. Fish were
anaesthetized using benzocaine solution, identified, measured, scale were obtained
from salmonids. All native species were returned and non-natives were retained and
photographed.
Some additional data was also obtained form anglers fishing on Loch Alvie.
8
3.
RESULTS
Four sampling locations were examined using the boat electro-fishing technique on
Speyside, Loch Beag, the Bogach, the Skating Pond in Grantown and the mainstem
near the confluence of the River Nethy. On Deeside two lochs, Davan and Kinord, were
examined.
3.1
Skating Pond, Grantown
Figure 2: Aerial view of the Skating Pond in Grantown on Spey showing proximity
to the River Spey. (Photo R. Laughton)
Located in Grantown on Spey (302983,827055) (Figure 1) the Skating Pond is a manmade feature which is fed by an input from the Kylintra Burn. Approximate area is 1.6ha
and the pond is generally shallow in depth typically between 1 to 1.5m. As the name
suggests the pond was created for skating and curling. However, as it has matured with
reed beds and vegetation it has begun to support a range of wildlife and bird species.
The pond is seldom fished and no data on the fish species present is available.
9
Initial observations gave little indication that there was many fish within this pond but
members of the pubic had reported sightings of a large golden coloured fish while
feeding the ducks. Redgewell, et al (2004) indicate that roach had already been
observed in the Kylintra Burn after a pollution incident in a pond further upstream and it
seemed likely that other fish species may also have escaped at that time from a privately
owned pond and entered the burn which supplies the Skating Pond.
The pond was surveyed on the 29th May 2005, three fishing runs covering both the reed
beds and vegetated areas of the pond along with the area of open water were
completed. The total time fished for the survey was 85 minutes. Table 1 indicates that
four species were captured, trout, eels, orfe (natural and golden forms) and a tench.
Trout
Golden
Eel
Orfe
Orfe
Tench
No
CPUE
No
CPUE
No
No
No
Caught
(fish.min-1)
Caught
(fish.min-1)
Caught
Caught
Caught
88
1.04
22
0.26
1
2
1
Table 1: The fish species caught and catch per unit effort (fish.min-1) in the Skating
Pond Grantown, 29th May 2005.
A substantial number of trout (Salmo trutta) were caught (n=88, CPUE 1.04fish.min-1).
Figure 3 provides a length frequency histogram for the captured trout and for the entire
catch lengths ranged from 160mm to 370mm and for brown trout. The ages ranged from
2+ to 4+ years. Although 2+ trout were the smallest and 4+ the largest there was
considerable over lap amongst the age classes make mean lengths for each difficult to
calculate. A number of scales indicated periods of rapid growth which reflects the better
feeding opportunities in the pond than in the burn. In addition some of the trout were
silvery in appearance indicating the onset of smolting.
Eels were the second most abundant species in the pond (N=22, CPUE 0.26fish.min-1).
10
Length frequency histogram for eels (Anguilla anguilla) is presented in Figure 4 and
lengths ranged from 200mm to 590mm. There were no clear age-classes evident within
the eel population.
18
16
Frequency
14
12
10
8
6
4
2
39
0
36
0
33
0
30
0
27
0
24
0
21
0
18
0
15
0
12
0
90
60
0
30
0
Length (mm)
Figure 3: Length (mm) frequency for trout caught in the Skating Pond, Grantown,
29 May 2005.
4
Frequency
3
2
1
70
0
65
0
60
0
55
0
50
0
45
0
40
0
35
0
30
0
25
0
20
0
15
0
10
0
50
0
0
Length (mm)
Figure 4: Length (mm) frequency distribution for eels caught in the Skating Pond,
Grantown, May 2005.
11
Figure 5: Orfe in natural colours (above) and Golden Orfe (below) captured in
Skating Pond, Grantown, 29th May 2005. (Photo R. Laughton)
A large golden fish was captured and this was confirmed as a Golden Orfe (Leuciscus
idus), (length 420mm) and an additional two natural coloured Orfe (Leuciscus idus),
(lengths 390mm and 400mm) were also caught (Figure 5). One juvenile tench (Tinca
tinca) was also captured (Figure 6).
Figure 6: Juvenile Tench captured in Skating Pond, Grantown, 29th May 2005.
(Photo R. Laughton)
12
3.2
Nethy Pool-Frankies Corner, Mainstem Spey
A roach was caught by an angler in the Nethy Pool on the mainstem of the Spey near
the confluence of the River Nethy during 2004 (Redgewell, et al 2004). Thus the boat
electro-fishing technique was trialled in this slower flowing reach of the mainstem.
Success was limited. A large adult salmon was disturbed by the technique but not
captured and only one small pike (length 290mm; age 3+) was successfully captured.
3.3
Loch Beag and the Bogach
Loch Beag (286264, 809165) (Figure 7) covers an area of 10ha and has a maximum
depth of 9m. It flows into Loch Alvie (286691, 809606), via a shallow channel. Fish could
readily move between the two lochs. The outflow of Loch Alvie is also a narrow channel
that flows through a marshy area known as the Bogach (288200, 809700) (Figure 7).
The channel has been dredged in the past and fish have been known to migrate from
the Spey to Loch Alvie via the Bogach, which drains into the R. Spey. Although the
channels are silted and well vegetated fish would still be able to move between the Spey
and Loch Alvie.
Two fishing runs were completed on Loch Beag covering the vegetated habitat and open
water areas. A fish finder was also used to direct fishing activities. Total fishing time was
110minutes and the fish species captured and CPUE are presented in Table 2.
Pike
No Caught
Roach/Rudd
Eel
No
CPUE
-1
Fry
CPUE
-1
(fish.min )
Caught
(fish.min )
L. Beag
16
0.15
18
0.16
Bogach
11
0.12
8
0.11
No Caught
50+
Tench
No
Caught
1
Table 2: The fish species caught and catch per unit effort (fish.min-1) in Loch Beag
and the Bogach 30th May 2005.
13
Figure 7: Map showing locations of Loch Beag and Bogach.
The boat electro-fishing was quite successful. Pike (N=18, CPUE=0.16fish.min-1) and
eels (N=16, CPUE=0.15fish.min-1) were captured. One large tench (length 480mm;
weight 8lbs) was also captured from Loch Beag (Figure 8).
Figure 8: Large Tench (8lb) captured in Loch Beag, May 2005. (Photo R. Laughton)
14
Observations from the fish finder indicated a substantial shoal of small fish was present
and a sample of 50+ roach and rudd fry was successfully collected using the electrofisher (Figure 9).
Figure 9: Roach and Rudd fry captured from Loch Beag Survey May 2005. (Photo
R. Laughton)
One fishing run of 90 minutes was completed on the Bogach. Two species were
captured, pike (N=11, CPUE 0.12fish.min-1) and eels (N=8, CPUE 0.09fish.min-1) (Table
2).
Data on pike and eels were combined for Loch Beag and the Bogach and are presented
in Figures 10a and 10b. Figure 10a suggests that four age classes of pike may have
been captured. Scales were collected from a number of the pike and analysis confirmed
that 2+ through to 4+ adults were present. Scales from the large 590mm pike were more
difficult to determine but age was estimated at 5+ or 6+. Spawning marks were evident
on several scales and indicated fish often spawned from age 3+ onwards. Scales also
indicated a period of rapid growth from around age 3+.
15
5
2+
3+
Frequency
4
3
2
4+
5+/6+
1
70
0
65
0
60
0
55
0
50
0
45
0
40
0
35
0
30
0
25
0
20
0
15
0
10
0
50
0
0
Length (mm)
Figure 10a: Length (mm) frequency histogram for pike captured in Loch Beag and
the Bogach, 30th May 2005.
4
Frequency
3
2
1
680
640
600
560
520
480
440
400
360
320
280
240
200
160
120
80
40
0
0
Length (mm)
Figure 10b: Length (mm) frequency histogram for eels caught in Loch Beag and
the Bogach, 30th May 2005.
Figure 10b* indicates that eels ranged from 220mm to 550mm. The sample is likely to
contain a range of ages but there are no clear indications of age classes.
16
3.4
Loch Alvie Angling Record
An additional report of an unusual fish (Figure 11) was provided by Ken Taylor, (Kinrara
Estates) from a pike angler fishing Loch Alvie on the 19th July 2005. The specimen was
confirmed as an Orfe, (Leuciscus idus).
Figure 11: Orfe captured by an angler in Loch Alvie, 19th July 2005. (Photo K.
Taylor)
3.5
Lochs Davan and Kinord
Figure 12: Map showing location of Lochs Davan and Kinord on Deeside.
17
Lochs Davan and Kinord are situated on Deeside near Dinnet and are within the Muir of
Dinnet National Nature Reserve (NNR) (Figure 12). Two fishing runs were conducted on
each loch encompassing a range of habitat types.
Table 3 indicates that three species were captured, perch, pike and eels in both lochs.
Total fishing time was 117minutes for Loch Davan and 205minutes for Loch Kinord.
Pike
No
Eel
CPUE
No
-1
Perch
CPUE
No Caught
-1
CPUE
(fish.min-1)
Caught
(fish.min )
Caught
(fish.min )
18
0.15
31
0.26
41
0.35
24
0.12
53
0.26
37
0.18
L. Davan
31/05/05
L. Kinord
01/06/05
Table 3: The fish species caught and catch per unit effort (fish.min-1) in Lochs
Davan and Kinord.
0
0
0
70
65
60
0
0
55
0
50
0
0
0
45
40
35
30
0
0
0
0
25
20
15
10
50
14
12
10
8
6
4
2
0
0
F req u en cy
Table 3 indicates that numbers of each species caught was very similar for both lochs.
Catch per unit effort was very similar between the two lochs for pike and eels but was
much higher for perch in Loch Davan.
Length (mm)
Figure 13a: Length frequency distribution for Perch in Loch Davan, 1st June 2005.
18
F req u en cy
5
2+
4
3
2
4+
1
80
12
0
16
0
20
0
24
0
28
0
32
0
36
0
40
0
44
0
48
0
52
0
56
0
60
0
64
0
68
0
40
0
0
Length (mm)
Figure 13b: Length frequency distribution for Pike in Loch Davan, 1st June 2005.
Age classes are estimated using Treasurer and Owen (1991).
F req u en cy
4
3
2
1
80
12
0
16
0
20
0
24
0
28
0
32
0
36
0
40
0
44
0
48
0
52
0
56
0
60
0
64
0
68
0
40
0
0
Length (mm)
Figure 13c: Length frequency distribution for eels in Loch Davan, 1st June 2005.
Figure 13a indicates that at least two age classes of Perch were captured in Loch
Davan. No scales or other material was collected for age determination. However, it
seems likely that the first group of perch are 1 year olds with a gap then to the second
larger group which are probably 3 years. It appears 2 years old are missing from the
catch.
Figure 13b indicated that at least two age classes of pike were captured. No scales were
taken and using data previously reported for Loch Davan by Treasurer and Owen (1991)
it seems likely first group are 2 year olds and the second 3 year olds.
Figure 13c illustrates the length frequency distribution for eels in Loch Davan. Sizes
range from 124mm to 576mm. No clear age structure pattern emerged.
19
Figure 14a indicates that at least two age classes of Perch were captured in Loch
Kinord. No scales or other material was collected for age determination. However, it
seems likely that the first group of perch are 1 year olds with a gap then to the second
larger group which are probably 3 years. It appears 2 years old are missing from the
catch.
Figure 14b indicated that at least three age classes of pike were captured. Again no
scales were taken and using Treasure and Owen (1991) as a guide it seems likely first
group are 2 year olds and the subsequent group is 4 year olds. Three year olds appear
to be absent from the catch.
Figure 14c illustrates the length frequency distribution for eels in Loch Davan. Sizes
range from 254mm to 662mm. No clear age structure pattern emerged.
20
12
Frequency
10
8
6
4
2
640
680
600
560
520
480
400
440
360
320
280
200
240
160
120
80
0
40
0
Length (mm)
Figure 14a: Length (mm) frequency distribution for Perch captured in Loch Kinord,
31st May 2005.
F req u en cy
4
3+
3
2+
2
4+
1
0
0
70
65
0
60
0
0
55
50
0
45
0
40
0
0
35
30
0
25
0
20
0
0
15
10
50
0
0
Length (mm)
Frequency
Figure 14b: Length (mm) frequency distribution for Pike captured in Loch Kinord,
31st May 2005. Age classes are estimated using Treasurer and Owen (1991).
5
4
3
2
1
0
40
80
120
160
200
240
280
320
360
400
440
480
520
560
600
640
680
0
Length (mm)
Figure 14c: Length (mm) frequency distribution for Eels caught in Loch Kinord,
31st May 2005.
21
4. CONCLUSIONS AND RECOMMENDATIONS
4.1 Survey methodology
The previous non-native survey of the lochs in Speyside and Deeside have concentrated
on gill netting as the primary sampling methodology (Redgewell, et al 2004) although
angling, minnow traps and electrofishing were also utilised with limited success. The
current survey utilised a boat based electro-fishing survey technique. In general the
approach was very successful in the shallow Skating Pond and also proved effective in
the deeper lochs such as Davan and Kinord, with a range of species captured.
There were a number of limitations, although a range of age classes were captured for
species such as pike, perch and trout, the younger age classes (0+, 1+) were always
missing. Equally the older larger fish may also be missed or evade capture.
The system operated with a large generator and the boats were powered by a petrol
outboard motor hence the operation was very noisy. This may well scare the fish and
reduce success. An electric outboard motor could be utilised but a large capacity
generator will always be required to deliver suitable power to attract fish from depth.
The anodes used in the current survey were 3m or 5m long and provided a good
operating range while remaining relatively easy to manipulate. Longer anodes would
become difficult to operate so water bodies deeper than 5m would be difficult to sample
with this technique. Fixed booms (Harvey and Cowx 1996) have also been used from
boats and this could also be used in the future. The anodes were fitted with mesh nets to
allow capture of the fish after it was attracted to the probe. This is technique is generally
frowned upon (SFCC 1998) since it can put the fish into tetanus and lead to damage.
Some damage to trout in the Skating Pond was recorded in the form of spinal injuries
probably resulting from direct contact with the anode ring while in the net. However, it
was limited to a few trout and no damage was observed amongst the non salmonid
species. This approach does allow a considerable flexibility for the operator and reduces
the number of staff required in the boats. However, further work is required to ensure
there is no unseen internal damage to the fish.
22
Timed fishings were carried out across a range of habitats in this survey. This proved
successful in answering the survey objectives. All the fishings were timed allowing CPUE
data to be generated however for future monitoring a more rigorous approach is
required. Set areas or banks could be marked and fished allowing revisits in the future,
fishing could be conducted in set patterns within or throughout a range of habitats. If
baseline surveys are to be established for lochs within Speyside and Deeside particularly
to meet the future demands of the Water Framework Directive then further though on the
most suitable approach is required.
On its own boat electro-fishing does provide all the data required to fully manage a loch
system. Fish finders were used in conjunction with the electro-fisher to guide the
operators to a shoal of fish and this illustrates the benefits of combining technologies.
Future surveys will require effective use of a range of techniques including acoustics,
netting, catch data and electrofishing to provide robust data for management purposes.
The main aim of the current survey was simply to determine if the technique was
suitable for determining if non-native species were present and providing further
baseline data on existing native species. This was achieved and with some refinements
boat electro-fishing should be considered as a useful technique for future census
surveys.
4.2 Fish Populations
The key purpose of the survey was to establish if there were any other non- native
species present which had not been detected by the netting survey in 2004. The findings
are worrying. In Loch Beag it is clear that the adult roach and rudd found in 2004 have
successfully spawned and fry are establishing. Fish fauna in Loch Beag is limited to pike
and eels so the effect may be limited within the loch itself. However, Loch Beag is
connected to Loch Alvie and eventually to the Spey, via the Bogach. The current survey
found no non-natives in the Bogach but it seems likely that they will eventually progress
through the lochs to the mainstem. The implications of a new species establishing within
the Spey is not clear, there may well be competition for food and habitat and existing
valuable stocks of trout and salmon may be affected.
23
Complete removal of the fish through poisoning is neither feasible in Loch Beag nor
desirable from the perspective of other wildlife interests. The channel between L. Beag
and L. Alvie is small and it may be possible to construct a barrier to contain the fish
although some may still be transferred by other animals and floods. It is recommended
that options to contain the roach and rudd be explored further. Further monitoring on the
Loch Beag and Alvie system is also recommended.
Tench was also caught at two locations the Skating Pond and Loch Beag. The large
individual caught in Loch Beag was capable of spawning but no juveniles were captured.
However, juvenile tench tend to be bottom orientated and difficult to catch via electrofishing so the result is not conclusive. The opposite was evident at the Skating Pond with
a single tench fry captured. This may indicate that larger tench are present and have
spawned in the pond. Suitable habitat exists for tench in both locations and given the
right conditions the species could establish.
Orfe were captured in the Skating Pond and were estimated at 4 to 5 years old. No
juveniles were captured but recent evidence form Redgewell et al (2004) indicates that
spawning populations already exist in ponds elsewhere in Speyside. An additional
record of an Orfe was also received from Loch Alvie in July 2005.
Lochs Beag and Alvie was stocked with non-native species in the past by the late Mr
Peter Braun, who had hoped to offer a wider range of fishing opportunities. Clearly some
of the introduced species are still present and worryingly the roach and rudd have begun
to spawn.
The orfe and tench present the Skating Ponds are also likely to originate from the
activities of the late Peter Braun. His own pond where he retained a range of fish
species is upstream and drains in the Kylintra Burn so passage from the upper pond into
the Skating pond would be relatively straight forward. There are tentative plans to drain
the Skating Pond in Grantown and remove a substantial portion of the reed beds and
vegetation. If this proceeds through simply draining the pond via the Kylintra Burn then
the non-natives present, tench and orfe, will easily be washed into the Spey and may
establish in the mainstem. It is recommended that measures are developed to collect the
24
fish from the pond prior to or during draining. This would provide some control on the
spread of non natives and also further data on the trout and eel populations present.
It is clear that fish species stocked into ponds pose a threat to the native fish fauna and
Redgewell, et al (2004) suggested mapping ponds within the Spey and Dee catchments
and creating an inventory of the species present to provide better information on the
extent of non-native species present. This should be coupled with a public awareness
exercise aimed at communicating the potential problems caused by the escape of nonnative fish, signal crayfish and invasive plants into the Spey and its tributaries.
The current survey also provided addition data on existing native fish populations. The
trout population within the Skating Pond was a surprising and interesting find. The age
structure was fairly complex and scales indicated that the majority of the trout had spent
their growth within the river. However, there was a proportion showed more rapid growth
consistent with enhanced feeding in ponds. A number of the trout were silvery indicating
they were smolting and ready to progress to sea. However, a clear exit from the pond is
not readily available and these may become constrained in the pond.
The Pond clearly provides a valuable habitat for trout and also for eels it is
recommended that if the pond is drained the trout and eel stocks be collected and held
in tanks and re-introduced back to the pond when the work is complete. Better provision
for fish passage in and out of the Pond should also be installed.
Results from Loch Beag and the Bogach for pike and eels were better using this
technique that the gill netting used previously in 2004. A wider range of sizes and age
classes of pike were collected and all the fish were returned alive. Scales from the pike
indicated fairly typical growth and age patterns for Highland lochs and was similar to
data from Treasurer and Owen, (1991) for Deeside lochs and previous data for Speyside
Lochs (R.Laughton, pers comm.). A good sample of eels was also gained but no age
structuring was possible. The results indicate that the Lochs provide valuable habitat for
eels which are currently in decline across the UK and Europe and again the introduction
of new species may have detrimental effects on this population.
25
Results from Loch Davan and Kinord were encouraging with no reports of non native
fish.
Perch, pike and eels were all captured. CPUE for pike and eels was similar
between each loch. However, CPUE for perch was much lower in Kinord than Davan
and there is no clear reason why this should be. There also appeared to be a lack of 2+
perch at both lochs. This could reflect a weakness in the age class which may relate to
the very dry summer prevailing in 2003. This may have led to a loss of habitat or
reduced spawning success.
The length frequency results for pike indicate a similar pattern to Loch Beag/Bogach
although 3 year olds appear to be absent from the Kinord catch. However, the pike
population seem similar in age structure to earlier data analysed by Treasurer and Owen
(1991) for Davan and Kinord.
The eel catch in both lochs was good and although age was not determined there is
probably a good range of age classes present. Similar to Loch Beag these Lochs offer
important refuges for eels in their freshwater development.
In general the survey illustrates the importance of collecting information on loch systems,
valuable data on fish populations was gained from lochs in both Deeside and Speyside.
Native populations include pike, perch, trout and eel and these areas offer important
habitats for these species some of which, eels and sea trout, are currently in decline
nationally. Non native fish species were also recorded in Loch Beag and Alvie on
Speyside and these are a direct result of mis-guided stocking activities to increase fish
variety for angling purposes. There was no evidence of any species establishing through
the release or discard of live bait by anglers. All the lochs surveyed either strongly
discourage the practice or have banned it and it is recommended that the Cairngorms
Park Authority further strength this approach.
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5. SUMMARY OF RECOMMENDATIONS
Fish fauna are an important part of the wildlife within the Cairngorms National Park and
the populations within stillwaters are still poorly monitored and understood. The following
actions are recommended:
•
A regular monitoring programme should be established for lochs within the
Cairngorms National Park. An initial baseline survey should be conducted for all
lochs and the followed by a rolling programme possibly visits every 3 to 5 years.
•
Monitoring should use multiple sampling techniques to a range of species are
caught and minimum damage is done to existing stocks. Boat electrofishing with
some refinements can provide a useful additional monitoring tool.
•
Some historical data for Lochs within the Cairngorms does exist and this should
be collated and reviewed.
•
Lochs should not be stocked with non-native species. In addition better
information and controls on trout stocking should also be considered.
•
The use of live baiting should be banned.
•
Sensible and sustainable fishing should be encouraged and developed.
•
An inventory of ponds within the Cairngorms National Park and species held
within them should be created and maintained.
•
A non-native species public awareness programme should be developed.
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6. ACKNOWLEDGEMENTS
This project was funded by Leader +, Cairngorms National Park Authority and Scottish
Natural Heritage.
We are grateful to Stephen Corcoran (Cairngorms LBAP Officer) who facilitated this
project.
The success of the project was due to the dedicated efforts of staff from Stellar
Environmental who completed the electrofishing to a high standard, often in atrocious
weather conditions. Thanks also must go to the staff of the Dee and Spey Fishery
Boards and Dr Peter Cosgrove who assisted with electro-fishing.
The authors are indebted to the following for allowing access to the lochs and providing
practical assistance when necessary Ken Taylor and Kirk Taylor of Kinrara Estate (Loch
Beag and the Bogach), Jamie Williamson of Alvie Estate (Lochs Beag and Alvie), Frank
Law of Seafield Estate (Skating Pond, Grantown), Abernethy Angling Association
(mainstem Spey), Scottish Natural Heritage (Lochs Davan and Kinord).
We are also grateful to Dr Peter Maitland (Fish Conservation Centre) and Ross Gardiner
(FRS Pitlochry) for their help in confirming the identity of the Orfe.
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7. REFERENCES
Harvey, J. and Cowx, I.G.
1996. Electric fishing for the assessment of fish stocks in
large rivers. In: (Cowx, I.G. ed) Stock Assessment in Inland Fisheries. Fishing News
Books. Pp11-26
K.J. Redgewell*, R. Laughton* and Hudson, A. 2004. Survey of Lochs in the Spey and
Dee Catchments for Non-Native Fish Species. Spey Research Report 05/04.
SFCC 1998.
A Guide to the SFCC Electrofishing Protocol. (ed Puhr, C.)
Scottish Fisheries Co-ordination Centre, Pitlochry. 19pp.
Treasurer, J.R. and Owen, R. 1991. Food and growth of pike, Esox lucius, in simple
fish communities in lakes of different trophic status. Aquatic Living Resources, 4, 289292.
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