Evaluation of biodiversity and distribution of macrobenthos communities of a nearshore windfarm in the Belgian part of the Nort Sea

The rapid development of offshore wind energy in the North Sea is a cornerstone of the transition to sustainable energy, yet it introduces significant physical modifications to marine habitats. Infrastructure such as turbine foundations and scour protection creates artificial hard substrates and alters local hydrodynamics, potentially reshaping the macrobenthic communities that are vital for nutrient cycling and food web stability. This study investigates the biodiversity, abundance, and biomass of infaunal macrobenthos (>1 mm) at the Norther Offshore Wind Farm in the Belgian Part of the North Sea. Research focused on the early operational period (2020–2022), utilizing Van Veen grab samples collected at varying distances from the turbines and within a designated reference zone. Taxonomic identification and biomass measurements were integrated with environmental data, including sediment granulometry and total organic matter (TOM). Statistical modeling, including Generalized Additive Models (GAMs), was employed to determine the influence of environmental drivers on community dynamics. Analysis of 157 taxa and over 23,000 individuals revealed a temporal increase in total abundance and species richness, suggesting a phase of progressive colonization following the initial construction disturbance. While biomass remained stable, a slight decline in Shannon diversity was noted, linked to the prevalence of opportunistic species. Sediment composition, especifically the fine fraction and TOM, proved to be the primary factors determining community structure. These results indicate that the wind farm had limited adverse effects on soft-bottom communities during its first years of operation, though long-term monitoring remains essential to track future ecological successions and cumulative environmental pressures.