We designed and tested a low-cost mixed methodology including Global Positioning System trackers, passive drifters (reused glass bottles), and Citizen Science (through instant message platform and email) for tracking carcasses of marine tetrapods. We performed four drift experiments, during the four seasons of 2019. We released 787 drifters (600 non-biological and 187 carcasses of seabirds, sea turtles, and cetaceans) at sea, at five equally separated distances (5–25 km) from the coast. Beach surveys and Citizen Science were implemented to recover the beached drifters.

We recovered 71.83% of non-biological and 27.27% of carcasses released. We tracked the movements of 38 carcasses (25 sea turtles and 13 cetaceans) with 17 GPS devices. The drifting time, until reaching the beach, ranged from 12h to 17 days for carcasses and 12h to 406 days for bottles. Citizen Science was the most important source of recoveries of non-biological drifters, representing 66.67% of the total bottles recovered. For carcasses, active search was the most important recovery source, representing 64.7% of the total carcasses recovered.

Our study contributes with new findings about drift patterns of marine tetrapods in the SWA and describes an accessible low-cost mixed methodology for small and medium-budget projects that can be replicated in other coastal regions of the world for tracking a wide range of marine tetrapod species.