Mapping Mediterranean bentho‐demersal communities to better inform marine conservation

Abstract Marine conservation and spatial planning are seeing increasing interest by stakeholders at the local, regional and international levels to balance biodiversity protection, sustaining fisheries and accommodating new uses of the marine environment. Marine protected areas (MPAs) are one of the most common conservation tools being implemented worldwide to reach conservation targets. However, their implementation does not usually take the heterogeneous distribution of bentho‐demersal communities into account. This has led to uneven conservation of existing communities, resulting in the misinterpretation of current protection coverage levels. Here, we mapped the distribution of the bentho‐demersal community of the Balearic Sea, in the northwestern Mediterranean Sea, using a joint species distribution model of 129 species of fish, crustaceans and cephalopods. We identified three distinct bioregions, and found that only 3.13% of the Shelf, 2.96% of the Upper slope and 0.89% of the Middle slope bioregions are covered by the 1089 km 2 of demersal no‐take MPAs included in our analyses. Bentho‐demersal communities were distributed mostly as a factor of bathymetry, but were also clearly delimited by bottom temperature, and had lower species‐rich communities in deeper bioregions. Furthermore, we found a negative effect of bottom trawl fishing on species richness in more heavily fished locations. Our results allow for the evaluation of an already implemented MPA network in the Balearic Sea, and suggest that more coverage is needed to fulfill current conservation set at the European and international levels. In order to achieve meaningful biodiversity conservation and help future marine conservation efforts, increases in MPA coverage will need to be supported by studies such as this one to ensure even representation of all marine bioregions and their communities.