Spatial Variability of Epibenthic Communities along the Moroccan Mediterranean Coast

Abstract

This study aimed to characterize epibenthic communities along the Moroccan Mediterranean coast and assess their environmental preferences. Information on these communities remains scarce compared with that available for the northern Alboran Basin. Data were collected at 60 stations during a survey conducted by the National Institute of Fisheries Research of Morocco along the Moroccan Mediterranean coast on board R/V Charif Al Idrissi in July 2024, at depths ranging from 39 to 620 m. The total number of species identified amounted to 157 taxa, including 9 algal species. Multivariate analyses were used to describe the communities inhabiting the study area and their environmental preferences. Four distinct epibenthic communities were identified by depth gradient as follows: continental shelf (39–135 m): characterized by high diversity associated with hard substrates and algal species; continental slope (91–272 m): marking a transitional zone between the coast and deeper areas, characterized by a low proportion of mud; upper slope (333–478 m): community showing preference for muddy substrates and representing a boundary separating the slope assemblage from the deeper community; middle slope (488–619 m): found on muddy substrates, typified by a key species of a vulnerable marine ecosystem. Finally, distance-based linear model (DistLM) analysis revealed that the variability observed was linked to several habitat characteristics, mainly depth as the primary ecological driver and depth-related variables, mainly granulometry, distance to land, organic matter (OM), and longitude. Hydrodynamic conditions and food availability also appeared to influence the spatial organization of these communities. These findings provide baseline knowledge on the Moroccan epibenthic communities, which are essential for effective fisheries management and conservation strategies.