crayfish survey report - hwa.uk.com · desktop study 3.1. a datasearch for all crayfish records...

Crayfish Survey Report Burnfield Meadow and Longstock Fen Leckford Dr Ben Rushbrook Chalkstream Invertebrates Project Officer Hampshire and Isle of Wight Wildlife Trust

www.hwt.org.uk Protecting wildlife, Inspiring people

CONTENTS 1. INTRODUCTION 1 2. ECOLOGY AND LEGISLATION 2 3. METHODOLOGY 4 4. RESULTS 6 5. DISCUSSION & RECOMMENDATIONS 9 6. SUMMARY AND CONCLUSIONS 13 7. REFERENCES 15 PLANS Plan 1: Map of Burnfield Meadow showing AR locations Plan 2: Map of Longstock Fen showing AR locations PHOTOGRAPHS Photo 1: Artificial refugia used in field survey Photo 2: Burrow system associated with ash Fraxinus excelsior root

system at Longstock Fen APPENDICES Appendix 1: Desktop study areas Appendix 2: Results of desktop study Appendix 3: Raw data for all five survey visits to Burnfield Meadow Appendix 4: Raw data for all five survey visits to Longstock Fen

1. INTRODUCTION

Background

1.1. The Chalkstream Invertebrates Project (referred to hereafter as the ‘CIP’) is a partnership project between the Hampshire and Isle of Wight Wildlife Trust and the Environment Agency. The project’s key objectives are to conserve, protect and promote the chalk river invertebrate fauna of the two counties with a specific focus on the white-clawed crayfish Austropotamobius pallipes and southern damselfly Coenagrion mercuriale, two internationally and nationally threatened species.

1.2. White-clawed crayfish are the only species of crayfish that is native to

Britain. White-clawed crayfish are protected by European and UK legislation and no works should be carried out that might harm white-clawed crayfish or the habitat in which it lives (Peay, 2000).

1.3. A number of non-native species of crayfish are now present within the UK.

Many, including the North American signal crayfish Pacifastacus leniusculus, will construct extensive burrow systems within the banks of rivers and streams that can dramatically impact on their structural integrity. Therefore, any works involving the construction of bankside structures should take into consideration the presence (or potential presence) of these species.

1.4. Furthermore, non-native crayfish species from North America can carry a

virulent disease, ‘crayfish plague’, which if transmitted to sites supporting white-clawed crayfish will result in a 100% mortality of the native species. Therefore, the presence of these species may require added bio-security measures to be incorporated.

Scheme of Works

1.5. The CIP Officer was contacted by Atkins Limited with regard to the potential

impact of works on white-clawed crayfish at two sites, Burnfield Meadow and Longstock Fen, associated with the Rivers Anton and Test near Leckford.

1.6. The works were to include the installation of control (sluice) structures, re-

opening of disused ditch networks and the seasonal re-wetting of the associated floodplain.

Survey Work

1.7. Following initial consultation, the CIP Officer was requested to undertake a

desktop study and subsequent specific field survey to determine the potential presence of white-clawed or the non-native signal crayfish.

August 2009 CraySur_Leckford.vf 1

2. ECOLOGY AND LEGISLATION

Ecology

2.1. The white-clawed crayfish Austropotamobius pallipes is a decapod crustacean of the family Astacidae. White-clawed crayfish are distributed throughout Europe and is at the most north-western limit of its range in Britain. The white-clawed crayfish is the only species of crayfish that is native to Britain and was formerly widespread where conditions were suitable.

2.2. In Britain, white-clawed crayfish occur in many types of water body

including fast moving rivers, slow moving canals and still waters such as lakes, reservoirs and water-filled quarries (Pöckl et al. 2006). Distribution is largely determined by geology and water quality, with crayfish occurring in areas with relatively hard, mineral-rich waters on calcerous and rapidly weathering rocks (Holdich, 2003).

2.3. The white-clawed crayfish favour habitats with an underlying substrate of

fine gravel / sand with some pebbles overlaid with aggregations of boulders and large cobbles / stones (>25cm diameter), areas of undercut bank and overhanging trees or other vegetation (Peay, 2003). Within these, white-clawed crayfish will occupy cryptic micro-habitats under rocks and submerged logs, among tree roots, algae and macrophytes. White-clawed crayfish are also able to burrow into suitable substrate (Holdich, 2003), although this behaviour is more commonly observed in non-native species.

2.4. As with all crustaceans, crayfish undergo a series of moults to grow, the

frequency of these moults decreasing with age. Crayfish usually reach sexual maturity after three to four years and, although the exact timing of breeding will depend on latitude and altitude, breeding takes place between September and November when water temperatures drop below 10°C for an extended period (Holdich, 2003). Eggs are fertilised externally and held beneath the abdomen by the female overwinter. Once hatched, the juveniles remain associated with the female’s abdomen for two – three moults, becoming independent from around June or July

2.5. The white-clawed crayfish is omnivorous, eating macroinvertebrates

(including worms, insect larvae and snails), some small fish and carrion when available (Holdich, 2003). Macrophytes, algae and detirtus are other key components of the white-clawed crayfish diet, and calcified plants are particularly attractive to crayfish as the provide a ready source of calcium during the moulting process (Holdich, 2003).


Legislation

2.6. White-clawed crayfish were once widespread across Europe and Britain. However, this species suffered a massive decline during the mid and late 1900’s and is now considered to be internationally and nationally rare. This decline has been due to habitat loss and degradation, pollution, but most significantly the introduction of non-native crayfish species and the disease ‘crayfish plague’ (carried by North American species such as signal crayfish Pacifastacus leniusculus and the red swamp crayfish Procambarus clarkii). Britain currently supports the greatest concentration of white-clawed crayfish in Europe (Holdich, 2003), but a number of populations have been eliminated since the early 1980’s (with the introduction of signal crayfish) and most extant populations are now concentrated in northern and central England.

2.7. As a consequence of this global and national decline, white-clawed crayfish

are protected under European and National legislation. They are listed under annexes II and V of the European Council Directive 92/43/EEC the Habitats Directive 1992 [transposed into UK Legislation through the Conservation (Natural Habitats &c.) Regulations 1994)] that requires:

• The identification and designation of important sites for white-clawed crayfish as special areas of conservation (SAC); and

• The taking in the wild and exploitation of white-clawed crayfish to be subject to management measures.

2.8. White-clawed crayfish are provided additional protection through their

inclusion on Schedule 5 [sections 9.1(taking) and 9.5)] of the Wildlife and Countryside Act 1981 (as amended) that makes it an offence to:

• Intentionally take [capture] a wild white-clawed crayfish; or • Sell, offer or expose for sale, or have in one’s possession or

transport for the purpose for sale, any live or dead wild white-clawed crayfish, or any part derived from it.

2.9. Non-native crayfish species are included in Section 14 of the Wildlife and

Countryside Act 1981 (as amended) and it is therefore an offence to release or allow to escape:

• Any wild animal which is of a kind not ordinarily resident in or a regular visitor to Great Britain in a wild state; or

• Any wild animal included in Schedule 9. 2.10. The signal crayfish is one of three species of non native crayfish that are

listed on Schedule 9, the others being the narrow clawed crayfish Astacus leptodacylus and the noble crayfish Astacus astacus. As a result, any signal crayfish captured during a survey cannot be returned to the wild.


3. METHODOLOGY

Desktop Study

3.1. A datasearch for all crayfish records held on the Hampshire and Isle of Wight Wildlife Trust’s database was undertaken for a 3km × 3km grid square surrounding each of the sites (see Appendix 1).

Survey Methodology

3.2. All surveys were undertaken by Dr Ben Rushbrook and supervised co-workers under Natural England Licence Number 20090491.

Habitat Appraisal and General Techniques

3.3. Initial site visits to Burnfield Meadow and Longstock Fen were

undertaken on 3rd June 2009 and a general assessment made of the potential suitability of the habitats present to support crayfish.

3.4. Any habitats considered potentially suitable for crayfish were then

investigated in further detail using one or both of the survey techniques detailed below. It is considered that using the combination of these two techniques increases the probability of recording any crayfish present.

3.5. Any crayfish captured were transfer to a secure container and processed on

the bankside. The following information was recorded; species, sex, carapace length, presence of physical damage, evidence of disease, breeding condition, moult stage, location and method of capture.

3.6. Any native white-clawed crayfish were then carefully return to the location of

capture. Any non-native crayfish were permanently removed from the watercourse.

3.7. Each site was visited on a total of five occasions between the 3rd June and

29th July 2009

Artificial Refugia (AR)

3.8. Artificial Refugia (AR) are a series of tubes of varying diameter set on a metal base (see Photograph 1). The ARs are utilised by crayfish for shelter in the same way they use natural features such as crevices beneath rock and burrows in the bank. Unlike conventional traps, animals are able to enter and exit the tubes at the will, which eliminate the risk of adverse impacts on non-target species such as water vole Arvicola terrestris and young otter Lutra lutra.

3.9. The ARs were deployed in suitable habitat, particularly in association with

the marginal zone, and were checked for the presence of crayfish fortnightly during an eight week period (i.e. four survey visits).

3.10. A total of eight ARs were deployed at Burnfield Meadow during the initial

visit (see Plan 1). All ARs were located during each of the four subsequent survey visits.


3.11. A total of twelve ARs were deployed at Longstock Fen during the initial site visit (see Plan 2). However, ARs 11 and 12 were re-positioned (annotated as 11i and 12i on Plan 2) on 15th June 2009 (due to the presence of cattle in the stream) and were then subsequently not located from the 29th June and 15th July 2009 respectively.

Hand-searching

3.12. Working in an upstream direction, areas of suitable habitat were identified and manually searched for the presence of crayfish. A purpose built survey viewer allowed surveyors to see the river / stream bed more clearly.

3.13. Cobbles / large stones, woody debris and other potential natural refugia

were lifted or turned, the bed beneath allowed to clear and the area inspected for crayfish. Where appropriate, any stones beneath were lifted too until the gravel, sand or soft substrate beneath was encountered and this was examined for crayfish and their burrows.

3.14. Where practicable, all material was return to its original position and

arrangement. 3.15. Hand searching was undertaken by the licence surveyor for a minimum

period of 15 minutes and often for notably longer. 3.16. In addition to hand searching, sweep netting in vegetation and under tree

roots was undertaken where appropriate. 3.17. Hand-searching was undertaken at Burnfield Meadow on 3rd June and 29th

July. 3.18. Hand-searching was undertaken at Longstock Fen on 3rd June, 15th June,

29th June and 29th July 2009. This was largely focused on the small carrier the Parsons Stream that forms the western site boundary and provides the majority of the suitable habitat at this site (see section 4.8).


4. RESULTS Burnfield Meadow

Habitat Appraisal

4.1. The main branch of the River Test forms the eastern and the southern boundary of the site (Plan 1). This area is considered to be predominantly unsuitable for crayfish as the channel is wide, deep and the bed substrate is dominated by silt with little or no natural refugia present.

4.2. In addition, a second branch of the River Test runs parallel to the main river

beyond the boundary of the site. This consists of areas of more suitable habitat for crayfish including gravel and stone substrate with aggregations of large rocks and soft bedrock with crevices.

4.3. The River Anton forms the northern boundary of the site and contains some

sub-optimal habitat for crayfish including small areas of gravel and accumulations of small cobbles and stone. The remainder of this stretch is dominated by silt with little or no natural refugia and is considered unsuitable for crayfish.

Desktop Study

4.4. Two records of crayfish were returned within the 3km gird square that

surrounds the site (Table 1 and Appendix 2).

4.5. This includes a record of signal crayfish within the River Anton located approximately 2km upstream of the site. In addition, a historic record (over 30 years old) of white-clawed crayfish within the River Test was returned, located within the 1km grid square to the north of the grid square that surrounds the site.

Table 1: Results of desktop study for Burnfield Meadow

Crayfish Species No. Site Name Grid Ref Year

Signal 1 River Anton SU 3730 4060 1997

White-clawed unknown River Test, nr Fullerton SU 3840 1977

Artificial Refugia

4.6. A single male white-clawed crayfish was recorded in the ARs during the four survey checks (see Table 2 and Appendix 3).


Table 2: Results of AR survey checks at Burnfield Meadow

Number of crayfish recorded Date

White-clawed Signal Comments

15th June 2009 0 0

29th June 2009 0 0

15th July 2009 0 0

29th July 2009 1 0 Large male in AR 8

Hand-searching

4.7. No crayfish were recorded during hand-search surveys (see Table 3 and Appendix 3).

Table 3: Results of hand-search surveys at Burnfield Meadow



3rd June 2009 0 0 Suitable habitat in River Anton

29th July 2009 0 0 Off site branch of River Test

Longstock Fen

Habitat Appraisal

4.8. The Parsons Stream is a small carrier stream running in a north-south direction that forms the western boundary of the site (see Plan 2). This contains sections with accumulations or brick, large rock / flint and stone. These areas are considered suitable to support crayfish.

4.9. The River Test forms the eastern boundary of the site with a small number

of habitat features that provide some sub-optimal habitat for crayfish at the top (north) of the site. These include a submerged ash Fraxinus excelsior root plate with associated ‘burrow’ system (see Photograph 2) and broken brickwork / large cobbles associated with the footbridge.

4.10. The remainder of this stretch supports little or no natural refugia and is

considered unsuitable for crayfish. Desktop Study

4.11. No records of crayfish were returned within the 3km gird square that

surrounds the site (Appendix 2).


Artificial Refugia 4.12. No crayfish were recorded in the ARs during any of the four survey checks

(see Table 4 and Appendix 4). Table 4: Results of AR survey checks at Longstock Fen



15rd June 2009 0 0 ARs 11 and 12 re-positioned

29th June 2009 0 0 AR 11 lost

15th July 2009 0 0 AR 12 lost

29th July 2009 0 0

Hand-searching 4.13. No crayfish were recorded during hand-search surveys (see Table 5 and

Appendix 4).

Table 5: Results of hand-search surveys at Longstock Fen



3rd June 2009 0 0 Suitable habitat on River Test

15th June 2009 0 0 Parsons Stream

29th June 2009 0 0 Parsons Stream

29th July 2009 0 0 Parsons Stream


5. DISCUSSION AND RECOMMENDATIONS

5.1. The white-clawed crayfish is a protected species under Schedule 5 of the Wildlife and Countryside Act 1981 (as amended). Consequently, it is an offence to take from the wild, sell or interfere with its habitat except under licence (Peay, 2000).

5.2. Therefore, where feasible works that may harm white-clawed crayfish or

their habitat should be avoided. Where necessary, works deemed likely to affect white-clawed crayfish must be performed under licence and disturbance must be kept to a minimum with every practicable means employed to safeguard this species and its habitat (Peay, 2000).

Burnfield Meadow

5.3. Based on the results of the desktop and field survey it is considered that the

River Anton at Burnfield Meadow supports a previously unrecorded small or low density population of white-clawed crayfish.

5.4. The desktop study also returned a record of the non-native signal crayfish

within the locality of the site.

5.5. The following Impact Assessment and Mitigation measures are based upon the current understanding of the proposals.

Impact Assessment

5.6. The location of the proposed sluice (Plan 1) is approximately 250m

upstream of the single male white-clawed crayfish recorded. The channel at this point is wide and deep with large silt deposits and would therefore be unlikely to support white-clawed crayfish. However, the bankside in the immediate location of the proposed works supports some features such as trees with submerged root plates that provide (sub-optimal) habitat for this species.

5.7. The works will take place in September 2009 over a two week period and

the working corridor to install the proposed sluice will affect a section of approximately 5m in width along both sides of the riverbank.

5.8. A coffer dam will be installed to locally drain water from an area of no more

than 2m in order to install the sluice. This dam will be installed by piling and there will be piling for the sluice to insure stability of the bank.

5.9. The sluice will be installed using a digger and the tracked part of the vehicle

will be away from the bank (to avoid bank collapsing) and the arm of the digger will extend to the river bank to carry out excavation works.

5.10. The detailed design of the sluice remains to be confirmed but is likely to be

predominantly comprised of re-enforced steel and concrete. 5.11. Based on presence of white-clawed crayfish within the site boundary and

the proximity of (sub-optimal) suitable habitat to the location of the proposed sluice, it is considered that there is potential for the proposed works to impact on this species. Specifically, the installation of the coffer dam and


associated de-watering of a localised section of bank may have a temporary, small scale negative impact on these species, and the installation of a sluice as detailed above will result in the loss of a short section of habitat.

5.12. However, the works are of a small scale, will at most have a minor negative

impact on a small population of white-clawed crayfish and will potentially provide wider biodiversity benefits. It is considered that through the implementation of the mitigation measure recommended below, there will be no long term negative impact of the works on these species. In fact, the inclusion of the recommended enhancement measures will in fact provide future habitat for this species.

Mitigation

5.13. All site staff must be briefed with regards to the presence of white-clawed crayfish on the site and must be familiar with the recommendations set out within this section.

5.14. The works are in keeping with best practice guidelines for the preferred

times (July to October) to undertake works that may involve the disturbance / removal of crayfish (Peay, 2000).

5.15. Draining areas of banks that support white-clawed crayfish refuges will

encourage the inhabitants to emerge (Peay, 2000). Therefore, the installation of the coffer dam can be used to encourage crayfish to voluntarily exit the banks. It is recommended that the effected area be drained for a period of two hours 2-3 days prior to the works with licensed ecologists present to collect any emerging crayfish and check / dismantle any potential refuges. The area then should be re-undated with water and a second de-watering undertaken immediately prior to the works (Peay, 2000). Alternatively, at a minimum a single draw down at least two hours prior to the works must be undertaken under the supervision of licensed ecologists.

5.16. Due to the localised nature of this disruption, it is considered appropriate

that all removed crayfish are released into the most suitable habitat in the immediate area. However, due to the historic presence of signal crayfish upstream of the site care should be taken in the identification of crayfish before they are re-released since the release of a non-native crayfish species is an offence under the Wildlife and Countryside Act 1981 (as amended). If any non-native species are identified then the Environment Agency and the CIP Officer at the Hampshire and Isle of Wight Wildlife Trust should be immediately informed.

5.17. Care must be taken to minimise the amount of disturbance to the bankside

during works. Excavation works should be undertaken using hand tools where practicable. However, where this is not feasible the soil should be carefully removed a layer at a time by an experience digger operative allowing a licensed ecologist to regularly check the area of works for crayfish.

5.18. Additional disturbance to the bankside and channel by site staff should be

avoided where practicable.


5.19. Care must be taken during and post-works to prevent pollution of the watercourse (e.g. by using drip trays for pumps and checking machinery regularly for oil leaks, etc) and measures must be incorporated into the plans to minimise siltation (e.g. silt blankets or meshes) downstream of the structure (Peay, 2000).

5.20. A number of bio-security measures must be put in place to ensure that

neither non-native crayfish nor the crayfish plague is transferred to the site. This will comprise the following:

• Where practicable staff should not move between sites. If this is not feasible, staff entering the site must thoroughly clean, disinfect and where feasible dry their equipment (i.e. waders, wellington boots, etc)

• All large equipment and machinery should be cleaned and allowed to dry prior to arriving on site.

• If stocking with aquatic plants or incorporating inorganic material, do not use material or stockists from watercourses that support non-native crayfish.

• Ensure that all staff are aware that it is illegal to move any species of crayfish to a new site without written permission from Natural England.

Enhancement

5.21. The opportunity exists to provide additional suitable habitat for white-clawed crayfish as part of the works. This could comprise the inclusion of features within the sluice structure such as artificial ‘burrows’ to provide supplementary refuge features or the importation of large stones or flint in suitable areas of the river channel downstream of the works.

Longstock Fen

5.22. No records of any species of crayfish were returned from the desktop study

or field survey. However, the habitat appraisal did indentify some areas of suitable or sub-optimal habitat for white-clawed crayfish (see section 4.8-4.9.

5.23. The following Impact Assessment and Mitigation measures are based upon

the current understanding of the proposals.

Impact Assessment 5.24. Based on the absence of records of white-clawed crayfish within the site

boundary and the immediate vicinity, it is consider reasonably unlikely that the proposed works will impact on this species. Furthermore, the works are of a small scale, will at most have a minor negative impact on a small population of white-clawed crayfish and potentially provide wider biodiversity benefits.

5.25. However, the proposed sluice will be located immediately downstream of a

series of sub-optimal habitat features for crayfish on the main River Test (section 4.9). Therefore, although on current evidence no mitigation is considered to be required, in order to avoid committing an offence it is recommended that one of the following two approaches are undertaken:


• A precautionary approach is applied and the works are undertaken on the basis that white-clawed crayfish are present and the mitigation measures set out in sections 5.13 – 5.20 are followed here also.

• A contingency plan is agreed whereby if any crayfish are recorded during the works, all operations are immediately halted and the Environment Agency and CIP officer (or other appropriately licensed ecologist) are consulted with regards to the implementation of appropriate measures for this.


6. SUMMARY AND CONCLUSIONS Scheme of Works

6.1. The Chalkstream Invertebrates Project (CIP) Officer at the Hampshire and

Isle of Wight Wildlife Trust was contacted by Atkins Limited with regard to the potential impact of works on white-clawed crayfish at two sites, Burnfield Meadow and Longstock Fen, associated with the Rivers Anton and Test near Leckford.

6.2. The works were to include the installation of control (sluice) structures, re-

opening of disused ditch networks and the seasonal re-wetting of the associated floodplain.

Survey Work

6.3. Following initial consultation, the CIP Officer was requested to undertake a

desktop study and subsequent specific field survey to determine the potential presence of white-clawed or the non-native signal crayfish.

6.4. A single male white-clawed crayfish was recorded during the field surveys

of Burnfield Meadow. In addition, the desktop study returned a record of signal crayfish and a (historical) record of white-clawed crayfish in the vicinity of the site.

6.5. No crayfish were recorded at Longstock Fen during the field surveys and

no records of crayfish were returned from the desktop study.

Discussion and Recommendations

6.6. Based on the results of the desktop and field survey it is considered that the River Anton at Burnfield Meadow supports a previously unrecorded small or low density population of white-clawed crayfish.

6.7. A series of mitigation measures for the proposed works at Burnfield

Meadow are recommended in the report above in order to avoid an offence under the Wildlife and Countryside Act 1981 (as amended).

6.8. It is considered reasonably unlikely that either white-clawed or signal

crayfish are present at Longstock Fen. However, the habitat appraisal did indentify some areas of suitable or sub-optimal habitat for white-clawed crayfish. Therefore, it is recommended that one of the following two approaches is adopted:

• A precautionary approach is applied and the mitigation measures set out for Burnfield Meadow are adhered to here also.

• A contingency plan for the discovery of white-clawed crayfish during the works is agreed with the Environment Agency and CIP Officer or other suitably qualified ecologist.

Conclusions

6.9. It is considered that with the implementation of the mitigation measure

recommended within this report, there will be no long term negative impact


of the works on white-clawed crayfish. In fact, the works themselves will potentially provide biodiversity benefits for this and other species.


7. REFERENCES Holdich, D (2003). Ecology of the white-clawed crayfish. Conserving Natura 2000 Rivers Ecology Series No.1. English Nature, Peterborough. Peay, S (2003). Monitoring the white-clawed crayfish Austropotamobius pallipes. Conserving Natura 2000 Rivers Monitoring Series No.1. English Nature, Peterborough. Peay, S (2000). Guidance on works affecting white-clawed crayfish. English Nature and Environment Agency Contract FIN/CON/139. English Nature, Peterborough. Pöckl, M., Holdich, D. & Pennerstorfer, J (2006). Identifying native and alien crayfish species in Europe. Craynet, Poitiers, France.


PLAN 1: Map of Burnfield Meadow showing AR locations

1

2

3

45

6

7

8

Proposed location of sluice

Approximate location of AR3

PLAN 2: Map of Longstock Fen showing AR locations

1

3

4

5

6

7

8

11i

11

12

9

10

12i

2

Proposed location of sluice

Approximate location of AR3

PHOTOGRAPHS

Photograph 1: Artificial refugia used in field survey

Photograph 2: Burrow system associated with ash Fraxinus excelsior root system at Longstock Fen

APPENDICES

APPENDIX 1: Desktop study areas

APPENDIX 2: Results of desktop study

APPENDIX 3: Raw data for all five site visits to Burnfield Meadow

Crayfish Recording Sheet

No. Species Sex CL (mm) Damage Disease Breeding Moult Sub-site Method1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20Additional Comments (other notable species, presence of pollution / litter, etc): 8 ARs set; Anton hand-search up to location of new structure - sub-optimal habitat with mainly silt and only a few natural refuges

Site Name: Burnfield Meadow, Leckford

River: River Test

Date / Site Visit: 03/06/09 / Site Visit 1

Surveyor: Ben Rushbrook + Chloe Delgery

Sheet Number: 1 of 1

NGR: SU 378 390



2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20Additional Comments (other notable species, presence of pollution / litter, etc): Bullheads in ARs. Trap7 vertical and without peg. Detailed walkover undertaken of the main river adjacent to site; deep in places, dominated by silt with very little in the way of cover - not searched as deemed unsuitable for crayfish.


River: River Test




NGR: SU 378 390



2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20Additional Comments (other notable species, presence of pollution / litter, etc): Spoke to Jeff Hounslow (07734 669738); Watch Estate, Chilbolton, in ponds / lakes has signals. Saw three signals walking on land 23rd June


River: River Test


Surveyor: Ben Rushbrook, Tiki Leggett + Jasmin Barwig


NGR: SU 378 390



2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20Additional Comments (other notable species, presence of pollution / litter, etc): Bullhead in ARs 3,4,7 + 8


River: River Test




NGR: SU 378 390


No. Species Sex CL (mm) Damage Disease Breeding Moult Sub-site Method1 A. pallipes M 48 Missing left 5th walking leg - - - AR8 - SU 38111 38913 AR2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20Additional Comments (other notable species, presence of pollution / litter, etc): Bullhead in ARs 2,4,6 + 7. Hand-search suitable habitat on eastern arm of R. Test


River: River Test


Surveyor: Ben Rushbrook, Chloe Delgery + Phil Latto


NGR: SU 378 390

APPENDIX 4: Raw data for all five site visits to Longstock Fen



2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20Additional Comments (other notable species, presence of pollution / litter, etc): 12 ARs set; Hand-search around footbridge in location of new structure

Site Name: Longstock Fen, Leckford

River: River Test




NGR: SU 365 379



2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20Additional Comments (other notable species, presence of pollution / litter, etc): AR 5 vertical; Hand-search suitable habitat in small channel. Plenty of bullhead seen h/s and in ARs and Stone Loach seen h/s by bottom footbridge


River: River Test




NGR: SU 365 379



2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20Additional Comments (other notable species, presence of pollution / litter, etc): Hand-search suitable habitat in small channel. Plenty of bullhead seen h/s and in ARs and Stone Loach seen h/s by bottom footbridge. AR 11 lost.


River: River Test


Surveyor: Ben Rushbrook, Tiki Leggett + Jasmin Barwig


NGR: SU 365 379



2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20Additional Comments (other notable species, presence of pollution / litter, etc): Bullhead found in most ARs. AR 12 lost.


River: River Test

Date / Site Visit: 15/07/09 - Site Visit 4



NGR: SU 365 379



2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20Additional Comments (other notable species, presence of pollution / litter, etc): Bullhead in Ars 6 + 7. Bullhead and stone loach seen during hand-searching of area were ARs 11 + 12 had been set


River: River Test

Date / Site Visit: 29/07/09 - Site Visit 5

Surveyor: Ben Rushbrook, Chloe Delgery + Phil Latto


NGR: SU 365 379

crayfish survey report - hwa.uk.com · desktop study 3.1. a datasearch for all crayfish records...

Documents