The loggerhead turtle (Caretta caretta), one of the most widespread and ecologically significant megafauna species in the Mediterranean, exhibits ontogenetic shifts in spatial distribution and habitat use throughout its life cycle, which further vary under different seasonal environmental conditions. However, how ontogeny and seasonality jointly shape the large-scale use of oceanic habitats remains poorly understood. Most research has focused on coastal areas, while the oceanic habitats, crucial for development, foraging, and migration have received comparatively limited attention. We investigated the spatial and seasonal patterns of oceanic loggerhead turtles in the Western Mediterranean and Adriatic Seas using standardized ferry-based surveys conducted between 2019 and 2024 within the LIFE CONCEPTU MARIS and FLT Med Net projects. For the first time at this large-scale, individuals were consistently assigned to three life stages (early juveniles, late juveniles, adults), enabling robust ontogenetic comparisons across seasons through multivariate analyses and stage-specific Species Distribution Models. Environmental associations partially overlapped among life stages but varied consistently with ontogeny and season, with differentiation being most pronounced in spring and autumn. Early juveniles were associated with warm, productive, and dynamic waters, whereas adults occurred mainly in deeper and more thermally stable offshore habitats. Late juveniles showed broader and more variable associations, often occupying transitional shelf-oceanic zones influenced by mesoscale activity. Across the basin, the Algerian, Tyrrhenian, and Adriatic regions emerged as recurrent offshore areas used by multiple life stages, although their spatial extent and seasonal importance varied among stages. By integrating ontogeny and seasonal perspectives, this study refines the understanding of loggerhead turtle spatial ecology in the Mediterranean and identifies persistent offshore areas of conservation relevance, supporting the need to extend management beyond coastal ecosystems.
From juveniles to adults: Ontogenetic and seasonal patterns of loggerhead turtles in oceanic Mediterranean habitats / Pasanisi, E.; Maffucci, F.; Atzori, F.; Azzolin, M.; Campana, I.; Carosso, L.; Castelli, A.; Costantino, M.; David, L.; Di-Méglio, N.; Farina, M.; Garcia-Garin, O.; Gregorietti, M.; Grossi, F.; Hochscheid, S.; Pace, D. S.; Pecoraro, M.; Roul, M.; Santini, E.; Tepsich, P.; Teti, R.; Vighi, M.; Vitale, M.; Arcangeli, A.. - In: MARINE ENVIRONMENTAL RESEARCH. - ISSN 0141-1136. - 219:(2026). [10.1016/j.marenvres.2026.108112]
From juveniles to adults: Ontogenetic and seasonal patterns of loggerhead turtles in oceanic Mediterranean habitats
Pasanisi, E.;Pace, D. S.;
2026
Abstract
The loggerhead turtle (Caretta caretta), one of the most widespread and ecologically significant megafauna species in the Mediterranean, exhibits ontogenetic shifts in spatial distribution and habitat use throughout its life cycle, which further vary under different seasonal environmental conditions. However, how ontogeny and seasonality jointly shape the large-scale use of oceanic habitats remains poorly understood. Most research has focused on coastal areas, while the oceanic habitats, crucial for development, foraging, and migration have received comparatively limited attention. We investigated the spatial and seasonal patterns of oceanic loggerhead turtles in the Western Mediterranean and Adriatic Seas using standardized ferry-based surveys conducted between 2019 and 2024 within the LIFE CONCEPTU MARIS and FLT Med Net projects. For the first time at this large-scale, individuals were consistently assigned to three life stages (early juveniles, late juveniles, adults), enabling robust ontogenetic comparisons across seasons through multivariate analyses and stage-specific Species Distribution Models. Environmental associations partially overlapped among life stages but varied consistently with ontogeny and season, with differentiation being most pronounced in spring and autumn. Early juveniles were associated with warm, productive, and dynamic waters, whereas adults occurred mainly in deeper and more thermally stable offshore habitats. Late juveniles showed broader and more variable associations, often occupying transitional shelf-oceanic zones influenced by mesoscale activity. Across the basin, the Algerian, Tyrrhenian, and Adriatic regions emerged as recurrent offshore areas used by multiple life stages, although their spatial extent and seasonal importance varied among stages. By integrating ontogeny and seasonal perspectives, this study refines the understanding of loggerhead turtle spatial ecology in the Mediterranean and identifies persistent offshore areas of conservation relevance, supporting the need to extend management beyond coastal ecosystems.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
