Towards an ecosystem approach to a simulated floating wind farm combined with climate change in the Bay of Biscay (France)

Abstract

The Bay of Biscay includes areas of environmental importance, with a wide variety of benthic habitats and rich biodiversity. However, it experiences strong anthropogenic pressures, and the effects of climate change are already evident. Renewable energy infrastructures are set to be installed with the aim of reducing the carbon footprint by 2050. However, their effects on the environment demonstrate the need for holistic studies prior to project design. The Ecopath with Ecosim model can be used to model the entire food web and explore different scenarios for changes in the Bay of Biscay. In this study, four scenarios are developed: (1) a reference scenario based on the 2007–2016 environmental conditions; (2) a climate change scenario (increased production and consumption rates of fish to reflect rising sea temperature, presence of non-indigenous species and local distribution maps derived from species distribution models); (3) an offshore wind farm scenario (a biofouling group, wind farm area closed to fishing activities and increased suitability of the area for species likely to aggregate under the turbines); (4) a cumulative effects scenario. The results are analyzed in terms of biomass and catches within the wind farm and the surrounding area. The main findings are that (1) the arrival of non-indigenous species could lead to a change in the structure of the local food web, resulting in a general increase in fish biomass; (2) the attractiveness of the wind farm generates cascading effects; (3) the combination of the wind farm and climate change could cause contrasting effects on biomass and catches depending on the trophic groups, as well as a potential reorganization of the current food web. These results reflect potential effects of floating wind farms on the structure of the food web that should be considered in fisheries management scenarios in the context of a changing environment.