High Level Environmental Screening Study for Offshore Wind Farm Developments – Marine Habitats and Species Project AEA Technology, Environment Contract: W/35/00632/00/00 For: The Department of Trade and Industry New & Renewable Energy Programme Report issued 30 August 2002 (Version with minor corrections 16 September 2002) Keith Hiscock, Harvey Tyler-Walters and Hugh Jones Reference: Hiscock, K., Tyler-Walters, H. & Jones, H. 2002. High Level Environmental Screening Study for Offshore Wind Farm Developments – Marine Habitats and Species Project. Report from the Marine Biological Association to The Department of Trade and Industry New & Renewable Energy Programme. (AEA Technology, Environment Contract: W/35/00632/00/00.) Correspondence: Dr. K. Hiscock, The Laboratory, Citadel Hill, Plymouth, PL1 2PB. [email protected] High level environmental screening study for offshore wind farm developments – marine habitats and species ii High level environmental screening study for offshore wind farm developments – marine habitats and species Title: High Level Environmental Screening Study for Offshore Wind Farm Developments – Marine Habitats and Species Project. Contract Report: W/35/00632/00/00. Client: Department of Trade and Industry (New & Renewable Energy Programme) Contract management: AEA Technology, Environment. Date of contract issue: 22/07/2002 Level of report issue: Final Confidentiality: Distribution at discretion of DTI before Consultation report published then no restriction. Distribution: Two copies and electronic file to DTI (Mr S. Payne, Offshore Renewables Planning). One copy to MBA library. Prepared by: Dr. K. Hiscock, Dr. H. Tyler-Walters & Hugh Jones Authorization: Project Director: Dr. Keith Hiscock Date: Signature: MBA Director: Prof. S. Hawkins Date: Signature: This report can be referred to as follows: Hiscock, K., Tyler-Walters, H. & Jones, H. 2002. High Level Environmental Screening Study for Offshore Wind Farm Developments – Marine Habitats and Species Project. Report from the Marine Biological Association to The Department of Trade and Industry New & Renewable Energy Programme. (AEA Technology, Environment Contract: W/35/00632/00/00.) iii High level environmental screening study for offshore wind farm developments – marine habitats and species iv High level environmental screening study for offshore wind farm developments – marine habitats and species CONTENTS High level environmental screening study for offshore wind farm developments – marine habitats and species EXECUTIVE SUMMARY ...............................................................................................................................1 1. Introduction ...............................................................................................................................................3 2. Biological characterisation of areas that may be developed for wind farms .............................................3 2.1 Species and habitats (biotopes) present .................................................................................................3 2.2 Variability and change in benthic communities ....................................................................................6 3. Potential ecological effects of offshore wind farm developments.............................................................9 3.1 Effects on existing habitats and species ................................................................................................9 3.2 New habitats and likely communities and species ..............................................................................22 4. Nature conservation.................................................................................................................................25 4.1 Introduction .....................................................................................................................................25 4.2 Existing areas designated for protection..........................................................................................26 5. Criteria to identify species, habitats and areas of marine natural heritage importance ...........................30 5.1 Introduction .........................................................................................................................................30 5.2 Species.............................................................................................................................................30 6. Deciding acceptability, managing risks...................................................................................................31 7. Making local environmental gains from offshore wind farm development ............................................32 8. Acknowledgements .................................................................................................................................34 PLATES ……………………………………………………………………………………………………..35 REFERENCES (REPORT AND APPENDICES) AND BIBLIOGRAPHY…………………………….….39 Appendix 1. Sources of published information used to identify biotopes likely to be present. Appendix 2. Likely distribution of seabed biotopes in areas proposed for offshore wind farms development, occurrence of nationally rare and scarce species and whether or not MarLIN sensitivity review undertaken. Appendix 3. Sensitivity to potential environmental change. Appendix 4. European Marine Sites. Appendix 5. Nationally rare & scarce species. v High level environmental screening study for offshore wind farm developments – marine habitats and species vi High level environmental screening study for offshore wind farm developments – marine habitats and species EXECUTIVE SUMMARY High level environmental screening study for offshore wind farm developments – marine habitats and species This report provides an awareness of the environmental issues related to marine habitats and species for developers and regulators of offshore wind farms. The information is also relevant to other offshore renewable energy developments. The marine habitats and species considered are those associated with the seabed, seabirds, and sea mammals. The report concludes that the following key ecological issues should be considered in the environmental assessment of offshore wind farms developments: • likely changes in benthic communities within the affected area and resultant indirect impacts on fish, populations and their predators such as seabirds and sea mammals; • potential changes to the hydrography and wave climate over a wide area, and potential changes to coastal processes and the ecology of the region; • likely effects on spawning or nursery areas of commercially important fish and shellfish species; • likely effects on mating and social behaviour in sea mammals, including migration routes; • likely effects on feeding water birds, seal pupping sites and damage of sensitive or important intertidal sites where cables come onshore; • potential displacement of fish, seabird and sea mammals from preferred habitats; • potential effects on species and habitats of marine natural heritage importance; • potential cumulative effects on seabirds, due to displacement of flight paths, and any mortality from bird strike, especially in sensitive rare or scarce species; • possible effects of electromagnetic fields on feeding behaviour and migration, especially in sharks and rays, and • potential marine conservation and biodiversity benefits of offshore wind farm developments as artificial reefs and 'no-take' zones. The report provides an especially detailed assessment of likely sensitivity of seabed species and habitats in the proposed development areas. Although sensitive to some of the factors created by wind farm developments, they mainly have a high recovery potential. The way in which survey data can be linked to Marine Life Information Network (MarLIN) sensitivity assessments to produce maps of sensitivity to factors is demonstrated. Assessing change to marine habitats and species as a result of wind farm developments has to take account of the natural variability of marine habitats, which might be high especially in shallow sediment biotopes. There are several reasons for such changes but physical disturbance of habitats and short-term climatic variability are likely to be especially important. Wind farm structures themselves will attract marine species including those that are attached to the towers and scour protection, fish that associate with offshore structures, and sea birds (especially sea duck) that may find food and shelter there. Nature conservation designations especially relevant to areas where wind farm might be developed are described and the larger areas are mapped. There are few designated sites that extend offshore to where wind farms are likely to be developed. However, cable routes and landfalls may especially impinge on designated sites. The criteria that have been developed to assess the likely marine natural heritage importance of a location or of the habitats and species that occur there can be applied to survey information to assess whether or not there is anything of particular marine natural heritage importance in a development area. A decision tree is presented that can be used to apply ‘duty of care’ principles to any proposed development. The potential ‘gains’ for the local environment are explored. Wind farms will enhance the biodiversity of areas, could act as refugia for fish, and could be developed in a way that encourages enhancement of fish stocks including shellfish.