Workshop to compile evidence on the impacts of offshore renewable energy on fisheries and marine ecosystems (WKCOMPORE)

Abstract

This report provides a comprehensive analysis and evaluation of the current state-of-the art in available evidence and science concerning the economic, social, and ecological impacts of offshore wind farms (OWF) and floating offshore wind farms (FLOW) on fisheries in the Baltic Sea, Celtic Seas, and Greater North Sea. It describes the observed and potential economic, social, ecological and cumulative impacts of OWF and FLOW, with a focus on the scope of the existing evidence base, data and methods to assess impacts, and mitigation options to avoid or reduce unwanted impacts. Overall, the workshop to compile evidence on the impacts of offshore renewable energy on fisheries and marine ecosystems (WKCOMPORE) highlights the need for additional high-resolution data, comprehensive assessments, and stakeholder involvement to better understand and mitigate the impacts of OWF and FLOW on fisheries and marine ecosystems. Specific ‘key findings’ arising from WKCOMPORE include: Economic and Social Impacts: The assessment of economic and social impacts of OWF and FLOW requires high-resolution data on vessel positions, fisheries catch and effort, fisheries economics, and social data. However, existing data are often insufficiently detailed and not well-linked, making comprehensive impact assessments a challenge. Both ex-ante (before) and ex-post (after) methods are used to assess these impacts. Studies have shown that OWF and FLOW can negatively affect income, fishing grounds, catching opportunities, and operating costs. It was concluded there are generally more studies reporting on negative impacts than positive benefits. Context factors such as the type of OWF and FLOW, development phase, and adaptive capacity of fisheries influence the nature and magnitude of impacts. No studies were found on trade-offs between economic impacts on fisheries and OWF and FLOW. Ecological Impacts (benthos and higher trophic levels): OWF and FLOW development phases have known or predicted local impacts on commercially fished species, but no population-level assessments were identified. The requirements for such analyses are, however, described. Assessing the potential impact of offshore wind farms (OWF) (fixed and floating) on commercial species requires a detailed understanding on how related human operations and the pressures they exert cause environmental effects leading to population-level impacts across spatial and temporal scales. Combined pressures caused by OWFs, climate change and other human pressures give rise to cumulative risks, demanding integrated environmental assessments such as cumulative effects assessments (CEA) and multi-scale management strategies. · The trait-based framework (TAFOW) applied in the current study links OWF-induced state changes to population characteristics and response traits, enabled species vulnerabilities to all phases of OWF life cycle to be assessed. · A total of 34 commercial species were assessed in the North Sea, Celtic Sea, and Baltic Sea, using the TAFOW framework, which identified that sediment resuspension was likely to be the most impactful state change, with highest vulnerabilities noted in the Celtic Sea driven by changes in larval dispersal and predator-prey interactions. The present study revealed that from the 34 commercially most important fisheries resources assessed; herring, great scallop, and monkfish are the most vulnerable species across the three regions. Trophic interactions and recruitment survival of fisheries resources are particularly vulnerable to pressures that are exerted by operational OWF. It was concluded there is insufficient evidence to directly assess and quantify the effects of OWF and FLOW on the Western Baltic herring stock, although there is no direct specific evidence to suggest existing OWF sites are impacting Western Baltic herring stocks. Baltic Proper ha