Threats to seabirds in Portugal: integrating data from a rehabilitation centre and stranding network

Abstract

Thousands of marine animals are injured and killed each year across Europe. Wildlife rehabilitation centres play an important role to rehabilitate sick and injured animals and return them to the wild. This study aims to assess seabird rehabilitation outcomes and causes of mortality of stranded seabirds in the central Portuguese coast. During a 7-year period (2010–2016) a total of 2042 admissions were registered, including 1135 live and 907 dead seabirds. The main causes for live admissions were trauma (30%) and toxicity (29.5%) and the main cause of all admissions (dead and alive) was entanglement/bycatch representing 42.5% of all seabirds. Large gulls, auks, gannets, and shearwaters and petrels were the most admitted seabird groups. A total of 445 seabirds (39%) were released to the wild following rehabilitation, 346 (31%) died during the rehabilitation process and 344 (30%) were considered untreatable after diagnosis and were euthanised. Considering the rehabilitation success rate and the high number of individuals admitted due to causes associated with human activities (entanglement/bycatch, trauma), marine animal rehabilitation centres and stranding networks are important to seabird conservation. These data also contribute to monitor the impacts of human activities on seabird populations outside their breeding areas.