European plaice movements show evidence of high residency , site fidelity , and feeding around hard substrates within an offshore wind f ar m

Offshore wind farms (OWFs) are expanding rapidly in the North Sea, often creating spatial conflicts with fisheries. Managing such conflicts requires knowledge on the impact of OWFs on the spatial distribution and mo v ement beha viour of fished species. Ho w e v er, such kno wledge is still lacking, especially for soft sediment fish such as flatfish, which are vital fisheries resources in the region. T heref ore, w e used acoustic telemetry to examine the spatial behaviour of European plaice in relation to an OWF and its str uct ures. In a small study area (1.37 km 2 ), we observed high residency for plaice around the turbines and scour protection la y er (SPL), which consists of large rocks around the turbine foun- dation. The fish primarily resided on sandy sediments near the hard substrates, but sho w ed a diurnal pattern of proximity to the turbine, being closer during the day. Considering their trophic ecology, these findings suggest that plaice mo v es to w ards the SPL f or feeding opportunities on the hard substrate, potentially leading to increased ecological fish production within OWFs. Although most plaice mo v ed a w a y from the OWF in winter, lik ely to w ards spa wning grounds, man y e xhibited high site fidelity returning to the study area after the winter migration. OWFs thus offer protection from fishing mort alit y as “closed” feeding grounds in spring and summer, but not during winter spawning migrations, which may result in spillo v er effects. These insights should inform local fisheries management in relation to plaice movement within and around OWFs.

RBINS Publication(s), Open Access, PDF available

acoustic telemetry, artificial reef effect, diurnal patterns, tagging, yaps.