Derwent Forest Reptile Survey Report. November 2009

Transcription

1 Capita Blackburn Business Centre, CastleWay House, 17 Preston New Road, Blackburn BB2 1AU Tel Fax Capita Symonds Ltd

2 Quality Management Job No Doc No. Final Project Derwent Forest Three Year Holding Programme Location Document Ref Reptile Survey Report File reference S:\Ecology\Projects\Derwent Forest Ecology\Reports 2009\Reports amended other timescales Nov09\Derwent Reptile Survey Report Final amended timescales 24Nov09.doc Date Prepared by Laura Hartley Signature (for file) Checked by Tabatha Boniface Signature (for file) Authorised by Lee Conroy Signature (for file)

3 Contents Contents 1. Summary 1 2. Introduction Background Legal status Policy Personnel & Quality Assurance 4 3. Methodology Background Survey Objectives Desk study Field Survey 5 4. Limitations 7 5. Site Description 8 6. Results Desk survey Field survey 9 7. Conclusions Advice and Recommendations References 12 Figures Figure 1 An example of a less vegetated disused railway track. Figure 2 An example of a building which requires asbestos management Figure 3 Gorse scrub encroaching onto a railway track adjacent to the bund Figure 4 A MAG type building adjacent to a section of Scots pine plantation woodland B1 B1 B2 B2 Figure 1 An example of a less vegetated disused railway track. B1...i Figure 2 An example of a building which requires asbestos management B1...i Figure 3 Gorse scrub encroaching onto a railway track adjacent to the bund B2...i Figure 4 A MAG type building adjacent to a section of Scots pine plantation woodland B2...i Figure 5 A less vegetated disused railway line requiring little management for reptiles prior to proposed works Figure 6 An example of a building which requires asbestos management... 1 Figure 7 Gorse scrub encroaching onto a railway line adjacent to the bund next to the building... 2 Figure 8 A Mag type building adjacent to part of the Scots pine plantation woodland... 2 Appendices Page i

4 Contents Appendix A Site photos A1 Appendix B Reptile presence results B1 Page ii

5 1 Summary 1. Summary Capita Symonds Ecologists, Blackburn were commissioned in April 2009 by Allerdale Borough Council to undertake a reptile presence survey on the existing Derwent Forest ex- Ministry of Defence (MOD) site at Broughton Moor, approximately 9km north west of Cockermouth, west Cumbria, central grid reference NY The site was formally used as a Royal Naval Armaments Depot but has since been acquired by Borough Council and Cumbria County Council Council. With the exception of a small amount of sheep and cattle grazing and more recently, police dog training, the site is now largely disused. There are 271 buildings on site, the majority made of asbestos, a material that has known carcinogenic effects if disturbed. The Council is proposing to undertake asbestos management of approximately 190 buildings in order to make them more secure and less of a health risk to members of the public and security personnel who enter the site. The management of asbestos primarily involves the removal of loose and broken panels from the floor and the buildings, in addition to securing structures and doorways in order to prevent potential future damage. Access to the buildings to undertake the management of asbestos is proposed on existing roads and along the disused railway lines, making it inevitable that disturbance will occur within these areas. The reptile survey aims to determine the presence of species in order to prevent disturbance or injury to any species. In England all six native species of reptile including the common lizard Lacerta agilis, grass snake Natrix natrix, adder Vipera berus, slow worm Anguis fragilis, sand lizard Lacerta agilis and smooth snake Coronella austriaca, are protected under the Wildlife and Countryside Act (1981) as amended, making it an offence to kill or intentionally injure any species. Additional protection is afforded to the sand lizard and smooth snake under the Conservation (Natural Habitats, &c.) Regulations (as amended) 1994 making it an offence to capture or possess them, or damage/obstruct access to places they use for shelter or protection. The site comprises a mosaic of species rich habitats suitable for reptile species including unimproved acidic grassland, showing transitions to calcareous grassland where there has been previous human intervention from lime chippings, marshy grassland, coniferous plantation woodland, semi-natural broadleaved woodland, scattered broadleaved trees and scrub and hedgerows with buildings, ponds, watercourses, heathland, an access road and overgrown railway lines that provide access to the buildings. In order to determine reptile presence across the Derwent Forest site, a combination of a desk based and field study were undertaken. The field study involved placing artificial refugia mats in suitable reptile habitat areas comprising south facing banks close to trees and scrub, particularly along the disused railway lines as these areas will receive most disturbance during the proposed management works. The refugia mats were checked over the period of May to July 2009, with additional observations made over the entire site. Page 1

6 1 Summary Common lizards were observed during the site visits in 2009 and previous studies indicate the presence of the common lizard, slow worm and adder (Hammond, N and F, 1996 cited in Entec, 2003). Biological records from the local records centre indicate the presence of common lizard, slow worm and grass snake on, and within 1km of the site. However, due to the secretive nature of reptiles, it is possible that further species or additional numbers are present on site. Recommendations to prevent a detrimental effect to reptile species and to comply with legislation include: Undertake works during September in order to avoid disturbance to reptiles during the breeding season (April/May), whilst ensuring reptiles have not entered hibernation (from October) and are still active enough to move themselves out of any potential harm. If works are to be carried out at other times of the year it will be necessary to ensure that no reptiles are present in the area of works prior to commencement and that reptile habitat is lost as a result. Avoid disturbance of bunds and where possible, plan works to take place on existing roads and along the least vegetated disused railway lines. Where vegetation clearance is required, undertake habitat management (such as sensitive strimming of tall vegetation) to make the proposed access routes unsuitable for reptiles. Management should be undertaken following the searching of species by an experienced ecologist and comprises the removal of scrub and potential refugia, such as log, stone piles and loose debris, where applicable, in addition to careful mowing of grassland habitats. Undertake all works under the supervision of an experienced ecologist who, immediately prior to management works along a particular track, will aim to ensure that all areas are clear from reptiles. Should any access routes be left undisturbed for a length of time (for example overnight), the ecologist will be required to re-search the areas prior to recommencement of works. The most onerous avoidance measures to avoid intention harm or injury to reptiles would entail the use of pitfall traps to trap and then translocate any reptiles caught to areas on site which will not be disturbed. However, for the current asbestos remediation proposals it is considered that this will method would be disproportionate to the element of risk. Page 2

7 2 Introduction 2. Introduction 2.1 BACKGROUND Capita Symonds Ecologists, Blackburn were commissioned in April 2009 by Allerdale Borough Council and Cumbria County Council to undertake a reptile survey at the existing ex-ministry of defence (MOD) Derwent Forest site at Broughton Moor, approximately 9km north west of Cockermouth, west Cumbria, central grid reference NY The council is proposing to undertake asbestos management on 190 of the existing 271 buildings on site, which at the time of survey in May to July 2009 was likely to involve: Removal of loose asbestos debris (around buildings and within rubble piles): Boarding up of potential access points below 2m high, in some buildings with asbestos, to prevent access; The retention of manure within buildings, but hand searching through material to remove loose asbestos fragments; The fencing off of the spoil heap; The potential removal of some buildings. Access to the buildings to undertake the management of asbestos is proposed on existing roads and along the disused railway lines, making it inevitable that disturbance will occur within these areas. 2.2 LEGAL STATUS In England all native species of reptile, including common lizard Lacerta vivipara, slow worm Anguis fragilis, sand lizard Lacerta agilis, grass snake Natrix natrix, adder Vipera berus and smooth snake Coronella austriaca, are protected under the Wildlife and Countryside Act (1981) as amended, making it an offence to kill or intentionally injure any species. Additional protection is afforded to the sand lizard and smooth snake under the Conservation (Natural Habitats, &c.) Regulations (as amended) making it an offence to capture or possess them, or damage/obstruct access to places they use for shelter or protection. The Natural Environment and Rural Communities Act 2006 (NERC Act) places a duty on statutory authorities, such as local authorities, to have due regard to conserving biodiversity in the exercising of their functions. 2.3 POLICY Planning Policy Statement 9 (PPS9) and its accompanying guidance document Planning for Biodiversity and Geological Conservation: A Guide to Good Practice ODPM 06/2005 sets out government policy on biodiversity and nature conservation and places a duty on planners to consider impacts on legally protected species as a material consideration when determining planning applications. Page 3

8 2 Introduction PPS9 also promotes sustainable development by ensuring that developments take account of the role and value of biodiversity and that it is conserved and enhanced within the development. The UK Biodiversity Action Plan (UKBAP) (Anon, 1995), written to fulfil the Convention on Biological Diversity in 1992, to which the UK is a signatory, has produced a national priority species list with all species included having specific action plans defining the measures required to ensure their conservation. Regional and local Biodiversity Action Plans (BAPs) have also been written and adopted to develop plans for species of nature conservation importance at regional and local levels. The UKBAP, as updated in 2007, lists all six native reptile species as conservation priorities: Common lizard Lacerta vivipara Slow worm Anguis fragilis Sand lizard Lacerta agilis Grass snake Natrix natrix Adder Vipera berus Smooth snake Coronella austriaca The common lizard, slow worm, grass snake and smooth snake are all found in Cumbria and are listed under the Cumbria BAP. 2.4 PERSONNEL & QUALITY ASSURANCE All ecologists employed by Capita Symonds are members of, or are under application for, membership of the Institute of Ecology and Environmental Management (IEEM) and follow the Institute s code of professional conduct when undertaking ecological work. The reptile surveys were undertaken in accordance with the Froglife Advice Sheet 10 and the Herpetofauna Workers Manual (Gent and Gibson, 1998) The reptile survey was undertaken by experienced Capita Symonds Ecologists including Tabatha Boniface, Nick White, Christopher Gaughan, Laura Hartley, Sarah Yarwood and Cazz Soper over the period of May to July Page 4

9 3 Methodology 3. Methodology 3.1 BACKGROUND A reptile survey on the existing Derwent Forest site (NGR at the central location NY048320) was undertaken in order to determine reptile presence prior to asbestos management works to assist determination of suitable mitigation to avoid any detrimental effect on reptile species. 3.2 SURVEY OBJECTIVES The survey was carried out to fulfil the following objectives: To identify any features on the site with the potential to support reptiles; To identify whether reptiles were present on site, particularly on and adjacent to the railway tracks that will receive most disturbance during the proposed works, at the time of survey; To identify the reptile species that have previously been recorded on the site; To provide an assessment of the likely importance of the site for reptiles and reptile conservation; To provide clear advice on any necessary mitigation and enhancement proposals which will enable the management works to proceed in full compliance with relevant wildlife and nature conservation legislation. 3.3 DESK STUDY The desk based study was undertaken in order to support the field survey and to establish the presence of reptiles on and 1 km around the Derwent Forest site. The local records centre at Tullie House Museum in Carlisle was contacted for all protected and rare records and previous studies on the site were cited in order to determine if any reptile species were recorded (Entec 2003). 3.4 FIELD SURVEY In order to establish reptile presence on site, surveys were undertaken in accordance with the Froglife Advice Sheet 10 and the Herpetofauna Workers Manual (Gent and Gibson, 1998). Sixty 0.5 m 2 butile refugia mats, were placed, particularly in areas considered to receive most disturbance from the proposed management works, by Chris Gaughan, Nick White and Tabatha Boniface on the 12 th May The mats were placed in areas considered to be reptile hotspots including sunny, south facing bunds close to trees and scrub, particularly close to the railway lines where access to the buildings proposed for works will be undertaken, and will consequently undergo most disturbance (see Appendix A for site photos). Page 5

10 3 Methodology Prior to placing the refugia mats on the floor, the vegetation was manually flattened down in order to help trap heat, creating a temperature gradient that would ultimately provide the reptile a more diverse place to seek refuge (Froglife Advice Sheet 10). The refugia mats were checked over the period of late May to mid-july 2009, when prevailing weather conditions and temperatures allowed, in order to determine reptile presence or likely. On all survey occasions, the weather conditions were dry commencing generally between 8.30 and 11am, or between 4 and 6.30pm when temperatures were not too high. On particularly hot days (when peak day time temperatures reached up to 29 o C), observations were made later in the evening to enable the temperature to cool down as reptiles are considered to be less active, with a reduced requirement to bask, in intense heat making the survey results less reliable. Observations of the artificial reptile mats involved lifting each mat to near vertical and recording reptile presence. Where stones and log piles were found across site, they were lifted up in the same way in order to assess reptile presence. In all cases, the refugia were placed back in exactly the same location as they were found in order to prevent potential disturbance to reptiles and other wildlife that may use them. Additional observations across the entire site were undertaken during the refugia checks and during further protected species surveys and involved walking slowly, treading lightly and scanning the area at least 3-4m in front. Particular focus was made on bare ground that could potentially be used by basking reptiles and where possible, the sun was behind the surveyor to prevent shadow disturbance. Page 6

11 4 Limitations 4. Limitations Reptiles can be challenging to survey as they tend to be secretive, camouflaged, occur in comparably low numbers on any site and maybe inactive during hot and dry periods. Therefore, their, or a negative result following a survey should be considered with caution and a precautionary approach during works should be adopted. In addition, the main birth and hatching of young occurs in July. Therefore, general activity levels of reptiles across a given site is reduced which potentially increases the difficulty in observing reptiles throughout this period. Page 7

12 5 Site Description 5. Site Description The Derwent Forest site is approximately 1200 acres in size and contains 271 buildings and structures (Billingham, 2002), the majority being made of asbestos, a material that has known carcinogenic effects if disturbed. The buildings are aligned in horizontal rows across the site and are connected by disused railway tracks that have largely overgrown with vegetation. The site was formally used as the Royal Naval Armaments Depot but has since been acquired by Allerdale Borough Council. With the exception of a small amount of sheep and cattle grazing particularly to the south and more recently, police dog training, the site is now largely disused. The site comprises a mosaic of species rich habitats suitable for reptile species including unimproved acidic grassland, showing transitions to calcareous grassland where there has been previous human intervention from lime chippings, marshy grassland, coniferous plantation woodland, semi-natural broadleaved woodland, scattered broadleaved trees and scrub and hedgerows with buildings, ponds, watercourses, heathland, an access road and overgrown railway lines that provide access to the buildings. The landuse immediately adjacent to the site boundaries is predominantly rural comprising minor roads and farmland. The River Derwent and the busy A66 road are located beyond the site to the south, the town of Flimby, an industrial estate and the Irish sea beyond are located approximately 1km to the west, the Great Broughton village is located to the east and south east with the large town of Maryport located approximately 2km beyond to the north. Page 8

13 6 Results 6. Results 6.1 DESK SURVEY Information from the local records centre indicates the presence of common lizard, slow worm and grass snake within 1 km of the site between 1990 and In addition, previous studies undertaken in 1996 indicated the presence of the common lizard, slow worm and adder on site, particularly on the spoil heap and around Peatmere Hill to the north of the site (Hammond, N and F, 1996 cited in Entec, 2003). 6.2 FIELD SURVEY The field survey undertaken in 2009 focussed on the railway lines which will be used to access the buildings during the proposed asbestos management works and will consequently receive most disturbance. Common lizards were observed under the reptile refugia adjacent to the railway lines and there were no incidental records during the site walkover. For full results, see Appendix B. Page 9

14 7 Conclusions 7. Conclusions The mosaic of habitats on the Derwent Forest site, including the south facing embankment with scattered scrub, unimproved grassland, broadleaved and coniferous woodland, bare ground and rock piles are considered suitable for reptiles. The field surveys in 2009 indicated the presence of the common lizard and previous studies have shown the presence of common lizard, adder and slow worm on site, with common lizard, grass snake and slow worm being recorded within 1km. The 2009 surveys focussed on areas that have potential to be disturbed during the proposed asbestos management works. Previous studies included the less disturbed areas of the site comprising the spoil heap and the Peatmere hills to the north. Therefore, it is possible that common lizard, adder and slow worm are present across the whole site but would not have been noted during this particular survey. In addition, the rural nature of the surrounding area suggests there are no barriers to reptile migration indicating all four species of reptile known in Cumbria, including the adder, slow worm, grass snake and common lizard, could all be present on the site. As discussed, reptiles can be difficult to survey due to their secretive nature and camouflage, therefore, the of species during the 2009 adjacent to the railway tracks should not be assumed definitive and a precautionary approach, where it is assumed all four reptile species known to Cumbria are present during the proposed management works. Page 10

15 8 Advice and Recommendations 8. Advice and Recommendations The following recommendations are aimed to make the habitats along the disused railway lines, that is the proposed vehicular access routes, unfavourable for reptile species to discourage them, and great crested newts which occupy a similar habitat, from using them to avoid negative impacts during asbestos management works. Legal requirements (in order to prevent potential injury or disturbance to reptile species): Undertake works during September in order to avoid disturbance to reptiles during the breeding season (April/May), whilst ensuring reptiles have not entered hibernation (from October) and are still active enough to move themselves out of any potential harm. If works are to be carried out at other times of the year it will be necessary to ensure that no reptiles are present in the area of works prior to commencement and that as little reptile habitat as possible is lost as a result. Avoid disturbance of bunds and where possible, plan works on existing roads and along the least vegetated disused railway lines; Where vegetation clearance is required, undertake sensitive habitat management (such as the gradual strimming of tall vegetation to a minimum height of mm using a strimmer or pedestrian flail) to make the proposed access routes unsuitable for reptiles. Management should be undertaken following the hand search of species by an experienced ecologist and comprises the removal of scrub and potential refugia, such as logs, stone piles and loose debris; Undertake all works under the supervision of an experienced ecologist who, immediately prior to management works along a particular track, will aim to ensure that all areas are checked to ensure they are clear of reptiles. Should any access routes be left undisturbed for a length of time (for example overnight), the ecologist will be required to re-search the areas prior to recommencement of works; The most onerous avoidance measures to avoid intention harm or injury to reptiles would entail the use of pitfall traps to trap and then translocate any reptiles caught to areas on site which will not be disturbed. However, for the current asbestos remediation proposals it is considered that this will method would be disproportionate to the element of risk. Biodiversity enhancement recommendations: Retention, enhancement and conservation management of the adjacent retained habitats with the creation of rock and log piles to increase structural diversity for reptiles away from any potential vehicular disturbance. Page 11

16 9 References 9. References Billington, G. E. (2002) Preliminary bat survey assessment Broughton Moor. Capita dbs for Allerdale Borough Council Entec (2003). Broughton Moor: Protected Species and Ecological Mitigation. Froglife Advice Sheet 10. Reptile Survey. An introduction to planning, conducting and interpreting surveys for snake and lizard conservation. Gent, T. & Gibson, S. (1998) Herpetofauna Workers Manual. Joint Nature Conservation Committee, Peterborough, UK. Cumbria BAP (2008). Cumbria Biodiversity Action Plan. Accessed 23/06/2009 Planning Policy Statement 9 (2005) Biological and Geological Conservation.ODPM Reptiles: Guidelines for developers (2004). English Nature publication. Page 12

17 Appendix A Site photos Appendix A Site photos Figure 5 A less vegetated disused railway line requiring little management for reptiles prior to proposed works. Figure 6 An example of a building which requires asbestos management Page Appendix A1 Allerdale Borough Council September 2009

18 Appendix A Site photos Figure 7 Gorse scrub encroaching onto a railway line adjacent to the bund next to the building. Figure 8 A Mag type building adjacent to part of the Scots pine plantation woodland Page Appendix A2 Allerdale Borough Council September 2009

19 Appendix B Reptile Presence Results Appendix B Reptile Presence Results Common lizard is the only reptile species recorded during the presence survey. The of a reptile species under each refugia mat has been classed as a likely because as discussed, reptiles are considered difficult to survey confidently. Date and time of survey 22/05/09 (09.00) 02/06/09 (08.30) 11/06/09 (08.45) 19/06/09 (17.30) 24/06/09 (17.30) 02/07/09 (09.45) 08/07/09 (08.40) Temperature 12 o C 18 o C 15 o C 20 o C 15 o C 24 o C 18 o C Reptile mat Number Common lizard Common lizard Common lizard Page Appendix B1

20 Appendix B Reptile Presence Results Date and time of survey 22/05/09 (09.00) 02/06/09 (08.30) 11/06/09 (08.45) 19/06/09 (17.30) 24/06/09 (17.30) 02/07/09 (09.45) 08/07/09 (08.40) Temperature 12 o C 18 o C 15 o C 20 o C 15 o C 24 o C 18 o C Reptile mat number Common lizard Page Appendix B2

21 Appendix B Reptile Presence Results Date and time of survey 22/05/09 (09.00) 02/06/09 (08.30) 11/06/09 (08.45) 19/06/09 (17.30) 24/06/09 (17.30) 02/07/09 (09.45) 08/07/09 (08.40) Temperature 12 o C 18 o C 15 o C 20 o C 15 o C 24 o C 18 o C Common lizard Common lizard Page Appendix B3