Onshore wind farm and transmission line developments have the potential to adversely affect freshwater and diadromous fish and associated fisheries through a number of mechanisms including:
- Increased sediment transport and deposition
- Pollution incidents
- Altered hydrological pathways
- Removal or degradation of fish habitat, including spawning areas
- Reduction in food supply
- Obstruction to upstream and downstream migration of fish.
It is important to avoid and/or reduce the possibility of such impacts occurring by careful pre-construction consideration, including site investigations, to select a suitable site and design, and good practice throughout construction.
The principal fish species of concern are Atlantic salmon, sea trout, brown trout and European eel, but for some developments other species, such as lamprey species, may be of concern. All are of conservation interest, and Atlantic salmon, sea trout and brown trout support important fisheries which could also be affected, either directly or by impacts on population size.
Marine Scotland Science (MSS) provides scientific advice in relation to the above potential impacts to the Energy Consents and Deployment Unit (ECDU), which have the responsibility - under Sections 36 and 37 of the Electricity Act (1989)- for processing applications, in excess of 50 megawatts, for the Scottish Ministers’ consent.
Under the Electricity Works (Environmental Impact Assessment) (Scotland) (EIA) Regulations (2000), the Scottish Ministers are required to consider whether any proposal for a wind farm is likely to have a significant effect on the environment. This guidance note outlines MSS advice on matters which should be addressed in the Environmental Statement (ES) associated with the application.
Information to be included in the ES is as follows:
1. A description of which fish species are present and their abundance in the waterbodies and watercourses which could be impacted by the development, and whether they are important for conservation or supporting fisheries
2. A description of the water quality of waterbodies which could be impacted and how the development may impact on these pre-construction conditions
3. A description of what activities during construction, post-construction and decommissioning have the potential to impact on fish or associated fisheries and what mitigation measures will be put in place to avoid and/or reduce this impact
4. Consideration of potential cumulative effects with adjacent and other developments
5. Proposals for monitoring during construction, post-construction and decommissioning
For more information, read the Guidance for Onshore Renewables, the Generic Monitoring Programme for Monitoring Watercourses in relation to Onshore Wind Farm Developments or email MS_Renewablesonshore@gov.scot.