Distribution patterns of marine megafauna density in the Mediterranean Sea assessed through the ACCOBAMS Survey Initiative (ASI)

• Published in: Frontiers in Marine Science Vol. 10
• Main Authors: Cañadas, Ana, Pierantonio, Nino, Araújo, Hélder, David, Léa, Di Meglio, Nathalie, Dorémus, Ghislain, Gonzalvo, Joan, Holcer, Draško, Laran, Sophie, Lauriano, Giancarlo, Perri, Morgane, Ridoux, Vincent, Vázquez, Jose Antonio, Panigada, Simone
• Format: Journal Article
• Language: English
• Published: Lausanne Frontiers Research Foundation 18-12-2023; Frontiers Media; Frontiers Media S.A
• Subjects: Biodiversity; Biodiversity and Ecology; Canyons; cetacean; Chlorophyll; Chlorophyll a; density surfaces; Distance; Distribution; Distribution patterns; Earth Sciences; elasmobranch; Environmental Sciences; Isobaths; large fish; Latitudinal variations; Mediterranean; Megafauna; Mixed layer; Mixed layer depth; modeling; Ocean floor; Oceanography; Sciences of the Universe; Sea surface; Sea surface temperature; Surface temperature; Surveys; Taxa; Vertebrates; Water depth; Mediterranean Sea; Strait of Gibraltar; Mediterranean Area; large fish; distance sampling; Mediterranean; modeling; density surfaces; abundance; elasmobranch; cetacean
• ISSN: 2296-7745; 2296-7745
• DOI: 10.3389/fmars.2023.1270917

The ACCOBAMS Survey Initiative (ASI) is the first synoptic large-scale survey of the entire ACCOBAMS Area and as such it plays a key role in filling the current gaps in our biological and ecological knowledge of large vertebrate species occurring in the region. Data gathered during the ASI were analyzed in a distance sampling surface-modelling framework to assess the summer distribution, densities and patterns, as well as to investigate the correlates of these parameters, for large vertebrate species and taxa in the Mediterranean Basin. Static and dynamic explanatory variables, including water depth (m), distance to depth contours (km), distance to canyons and seabed slope (km), sea surface temperature (°C), mixed layer depth (m) and levels of chlorophyll-a (mg/l), were considered to predict density and compute its variance spatially at a resolution of 10x10 km. A strong longitudinal gradient from low densities in the east to high densities in the west is shared by most taxa. In addition, several taxa also showed a less marked latitudinal gradient varying in direction according to species, and finally, a few of them exhibited patchy distributions.