Marine litter can shift sea turtle nests toward the shoreline

Marine litter is an emerging threat to sea turtle rookeries, yet its effects on nesting behaviour remain poorly understood. In this study, we investigated how macro-litter accumulation on beaches influences the spatial distribution of loggerhead turtle (Caretta caretta) nests on Boa Vista Island, Cabo Verde. We mapped litter across 40 surveyed beach sections and combined these data with nest locations and control points. Our results revealed that females tend to nest closer to the shoreline when litter is more abundant, overriding natural mid-beach nesting preferences. We suggest that marine litter adds a new dimension to the phenomenon of coastal squeeze, further reducing the availability of suitable nesting habitat. The mechanism identified is likely relevant in other major nesting areas where litter accumulates, potentially reshaping habitat use for other populations worldwide. Our findings highlight the indirect consequences of marine litter and the need for further research on its ecological implications.