All shallow coastal habitats matter as nurseries for Mediterranean juvenile fish

Abstract Coastal zones are ecosystems of high economic value but exposed to numerous disturbances, while they represent nurseries for many fish species, raising the issue preservation their functions and services. In this context, juvenile assemblages all types habitats present in shallow coastal were studied on south-east coast France using underwater visual censuses warm (June–July 2014) cold (April 2015) periods. A total fourteen habitat characterized, which could be grouped into three broad categories, rocky substrates (natural artificial), sedimentary bottoms with levels granulometry, seagrass beds including Cymodocea nodosa Posidonia oceanica meadows; ecotones or interfaces between categories individualized as particular types. The abiotic biotic descriptors 14 did not vary time, except a higher cover percentage canopy height macrophytes period, increased three-dimensional structure some habitats. taxonomic composition density analyzed both multivariate univariate descriptors, after grouping 57 species recorded 41 well-individualized taxa. Juvenile fishes types, mean richness abundance during than period. richest terms natural other Although assemblage differed among periods, most abundant Atherina sp., Sarpa salpa , Gobiidae, Symphodus spp., Pagellus spp. several Diplodus colonized 7 up different (depending taxa) life. Most settled one few specific rapidly adjacent when growing. This study provided evidence role varying pattern occupation space time by stages. It highlighted importance mosaic complete development life stages fishes, diversity fisheries resources Mediterranean Sea.