Dear all, On behalf of my co-authors, I am pleased to announce and share our recent paper titled: "*Environmental influence on Bottlenose dolphin (Tursiops truncatus)* *abundance in Southern Portugal*". The full paper is available here: https://doi.org/10.1016/j.rsma.2025.104569
Feel free to email me if you have any questions. Abstract: The common bottlenose dolphin (*Tursiops truncatus*) is a keystone species and bioindicator of marine ecosystem health. Factors influencing its abundance in southern Portugal’s Algarve region remain poorly understood. This study examines nine years (2015–2023) of sighting records, collected through platforms of opportunity and a dedicated research vessel, to assess the relationship between monthly dolphin abundance and key oceanographic factors across four age classes (adults, juveniles, calves, and neonates). Among the environmental variables assessed, sea surface temperature (SST), chlorophyll-a (Chl-a), coastal upwelling index, dissolved oxygen, and sea surface salinity, only SST and Chl-a were retained as key predictors in the final ecological models (GLMMs). Results showed a significant positive relationship between Chl-a and adults abundance, while SST was positively correlated with neonates but negatively correlated with adults and juveniles abundance. This pattern was reflected in a geospatial temperature-driven gradient, with neonates primarily concentrated in warmer eastern waters, and juveniles in cooler western waters closer to the Atlantic. The indirect effects of SST and Chl-a on dolphin abundance, mediated through prey availability, and the direct effects of SST on thermal regulation, were explored. Warmer waters may act as a thermal barrier, restricting the occurrence of older dolphins while providing a thermal ‘cushion’ for neonates, enhancing their survival chances. These findings underscore the need to validate the Algarve’s potential role as a key breeding and nursery ground, essential for shaping age-specific conservation strategies within the Site of Community Importance (SCI) designated in 2019 to protect Annex II species.
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