Abundance of juvenile of commercial species in coastal habitats, the case of the Artabro Gulf (NW Spain)

A wide variety of species use coastal habitats at some or all stages of their life cycle. These habitats are recognized as nurseries for many species. During their early life stages, most commercially exploited species rely on shallow coastal wa-ters, which are heavily affected by anthropogenic influences. This study focuses on characterizing the habitats of juvenile fish of the main commercial species in the Ártabro Gulf (northwest Spain), through the analysis of trawl survey data collected on soft-bottom substrates between 2017 and 2024. We used generalized additive models to quantify the influence of environmental variables (exposure, type of substrate, bottom depth, zone and season) on the abundance of five ecologically and commercially important benthic species in their juvenile stage. Our results identified the Ares-Betanzos zone as the primary nursery ground due to its sheltered conditions, which resulted in the highest juvenile densities. Exposure and depth were found to be the most important determining factors: sheltered areas had densities eight times higher than exposed sites, and maximum abundance was recorded at depths of 30–40 m. Among the species analysed, the spider crab and solenette showed a preference for shallow waters (less than 20 m deep), while the scaldfish preferred muddy sediments. These findings provide a scientific basis for establishing conservation measures, such as seasonal fishing closures or the designation of marine protected areas in shallow waters. This will ensure the sustainability of the region’s fishery resources.