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 e.g. fuel, concrete spillage, incorrect use of flocculants (for sediment control); altered hydrological pathways; removal or degradation of fish habitat, including spawning areas; reduction in food supply and 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 (see here).
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 of economic value which could also be affected, either directly or by impacts on population size.
Marine Scotland Science (MSS), which is part of the Scottish Government, regularly provides scientific advice to Energy Consents Unit (ECU) in relation the potential impacts of wind farm developments on the above fish. ECU has the responsibility, under Sections 36 and 37 of the Electricity Act (1989), for processing applications for electricity generating stations of 50 megawatts or more, power lines and associated infrastructure for Scottish Ministers’ consent. Under the Electricity Works (Environmental Impact Assessment) (Scotland) (EIA) Regulations (2017), Scottish Ministers are required to consider whether any proposal for a wind farm is likely to have a significant effect on the environment. An application for an Electricity Act consent for an EIA development must be accompanied by an Environmental Impact Assessment Report (EIAR). This guidance note outlines MSS advice on matters which should be addressed in the EIAR.