This dataset presents the decapod species and abundance, along with the habitat (detached seagrass leaves, fine fraction of detritus, detrital macroalgae, organic matter in sediments, seagrass shoot density and height of unburried rhizomes), landscape (landscape configuration) and geographical attributes (inlet aperture and confinement) in Posidonia oceanica seagrass meadows in 5 localities accross the NW Mediterranean sea.
We found that geographical level attributes (i.e., inlet aperture, confinement) affected the most the decapod assemblages, while we only found a modest contribution from habitat (e.g., detritus biomass, sediment organic matter) and landscape attributes (e.g. fragmentation). We suggest that decapod assemblages are driven by the interaction of multiple processes occurring at different scales and other highly stochastic phenomena such as larval dispersion and recruitment, This study was supported financially by the Spanish government (projects CTM2010-22273-C02-01 and CTM2013-48027-C3-1-R). The Spanish government also supported AMR (scholarship BES-2011-046849), Table 1. Decapod species and number of total individuals of 5 randomly selected quadrat (40 cm x 40 cm) found in Aiguablava (Ag), Rustella (Ru), Giverola (Gi, Cativa (Ca) and Portlligat (Po) in continuous seagrass meadows of Posidonia oceanica (CO), patches in sand matrix (PS) and patches in rock matrix (PR). Table 2. Habitat attributes and geographical attributes of 5 randomly selected quadrat (40 cm x 40 cm) found in Aiguablava (Ag), Rustella (Ru), Giverola (Gi, Cativa (Ca) and Portlligat (Po) in continuous seagrass meadows of Posidonia oceanica (CO), patches in sand matrix (PS) and patches in rock matrix (PR), Peer reviewed

10 pages, 5 figures, 2 tables, supplementary data https://doi.org/10.1016/j.marenvres.2024.106464.-- Data availability: The data that support the findings of this study are openly available in the DIGITAL.CSIC repository at https://doi.org/10.20350/digitalCSIC/16181, Seagrass meadows are biodiversity hotspots for invertebrate species including decapods. Understanding the drivers of species abundance, richness and diversity of decapod assemblages is crucial for the conservation of such hotspots, but how drivers act across multiple spatial scales remains unexplored. Here we describe the decapod assemblages of Posidonia oceanica seagrass meadows and assess the influence of attributes from three increasing spatial scales (habitat, landscape, and geographical levels) on the assemblages’ structure and composition, as well as the variability partitioning among each one of these levels. Overall, geographical level attributes (i.e., inlet aperture, confinement) affected the most the decapod assemblages, while we only found a modest contribution from habitat (e.g., detritus biomass, sediment organic matter) and landscape attributes (e.g., fragmentation). We suggest that decapod assemblages are driven by the interaction of multiple processes occurring at different scales and other highly stochastic phenomena such as larval dispersion and recruitment, This study was supported financially by the Spanish government (projects CTM2010-22273-C02-01 and CTM2013-48027-C3-1-R). The Spanish government also supported AMR (scholarship BES-2011-046849), With the institutional support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S), Peer reviewed