The area south of the Po River delta (Italy) is a hot spot for strandings of loggerhead sea turtles

Abstract

The northern Adriatic Sea is an important foraging ground for the loggerhead sea turtle Caretta caretta (Linnaeus, 1758) within the Mediterranean Sea. Here, stranding patterns of loggerhead sea turtles were examined over a four-year period (2019–2022) along a short (17 km) stretch of the Italian coast south of the Po River delta. A total of 355 records (alive, n = 24; dead, n = 331) were analysed, and the curved carapace lengths (CCL, notch to tip, cm) mainly reflected large juveniles and sub-adults (average CCL = 57.2 cm; 95% CI = 55.6–58.7). The month of July was identified as the critical month with the highest number of strandings, mirroring migratory processes towards this area during warmer months. The number of stranded turtles•km−1 as well as the absolute number of strandings along the short stretch of the coast might suggest this area as the most impacted in the Mediterranean Sea. This research emphasizes that human activities in the waters south of the Po River delta, particularly trawl fishing, are the primary cause of loggerhead sea turtle strandings and that tracking stranding patterns can offer valuable information about the geographic ranges, seasonal movements, and life cycles of this species.