Impacts of floating offshore wind infrastructure on the distribution and behaviour of fish and marine mammals: IFLOW

Moored offshore floating infrastructure (e.g. renewable energy, hydrocarbon exploitation, hydrogen production, aquaculture) will expand significantly in scope and extent, as urbanisation of coastal shelf seas accelerates globally. Moored floating structures associated with offshore wind turbines are likely to be deployed across wide areas, including increasing depths and distances from shore. Floating windfarms are therefore increasingly likely to be deployed within highly productive shelf areas important for many wide-ranging migratory species including benthopelagic fish and their predators (marine mammals, seabirds, elasmobranchs). Ecological significance of such structures, in terms of influence on mobile species, remains poorly understood but could be substantial based on current knowledge about the ability of existing static offshore structures (e.g. oil & gas platforms) to attract and retain fish communities [1]. Attraction of fish to floating objects in (sub-)tropical waters is well known and widely exploited through use of Fish Attracting Devices (FADs; [2]). However, much less is known about comparable effects of floating structures at higher latitudes. If persistent fish aggregations develop around floating offshore windfarms or similar infrastructure, this could influence the distribution of other predators, including Scottish Priority Marine Features such as marine mammals, seabirds and elasmobranchs, with unknown conservation consequences. This research links to ScotMER knowledge gaps surrounding overlap between seabirds and floating offshore wind (and drivers of this overlap), behaviour of marine mammals in locations suitable for renewable energy developments, effects of renewables on foraging behaviour and changes to prey distribution, and thus potential for population-level impacts, with reef/aggregation effects specifically identified. This project seeks to develop understanding of spatiotemporal distribution of fish in shelf seas in response to moored floating offshore structures, and clarify whether such structures represent attractive foraging locations for top predators (vocalising cetaceans).