Seabirds face numerous threats, including climate change, accidental capture in fishing gear, and predation by invasive species.
Now, a new danger has emerged: plastic pollution. As seabirds search for food, they are increasingly ingesting plastic, particularly the petrel species.
This article presents the findings of a study tracking over 7,000 petrels of 77 different species to determine their exposure risk to plastic pollution.
The study highlights the regions where seabirds are most vulnerable, emphasizes the impact on various species, and underscores the urgent need for international efforts to combat plastic pollution.
Plastic Exposure Risk and Geographic Hotspots: Based on the research, many seabird species spend significant time in areas with high concentrations of plastic. Enclosed seas like the Mediterranean and the Black Sea pose the greatest plastic exposure risk due to the entrapment of plastic debris. These regions account for over half of the global plastic exposure risk for petrels, affecting all four studied species that forage there.
Additionally, petrel species in remote areas, including the north-west and north-east Pacific, south Atlantic, and south-west Indian Ocean, face risks due to the transport of plastic by mid-ocean gyres. Alarmingly, a quarter of the petrels’ plastic exposure risk occurs in international waters, necessitating global cooperation to protect seabirds and marine wildlife.
Vulnerable Species: The plastic exposure risk varies among species and depends on whether it is the breeding or non-breeding season. Critically endangered species like the Balearic shearwater and the Newell’s shearwater, endemic to Hawaii, face high risks of plastic exposure. Similarly, the spectacled petrel, which nests exclusively on Inaccessible Island in the south Atlantic Ocean, is also highly vulnerable. Even species with low exposure risk, such as the northern fulmar and snow petrel, have been found to ingest plastic, indicating the pervasive nature of oceanic plastic pollution and its impact on seabirds globally.
The Impact of Plastic Pollution on Seabirds: Plastic ingestion is often accidental, with seabirds mistaking it for food or consuming it through prey ingestion. This ingestion can lead to injuries, poisoning from toxic chemicals released by the plastic, and starvation as the stomach fills with plastic. Studies have shown that more than 60% of fledgling flesh-footed shearwaters exceeded international targets for plastic ingestion, with 16% surpassing these targets after just one feeding.
Moreover, the breakdown of plastic into microplastics can cause inflammation in a bird’s digestive system, known as “plasticosis.” Considering the existing threats faced by petrel species, plastic exposure further undermines their resilience and survival.
The Need for International Cooperation: This study represents a significant advancement in understanding the threat of plastic pollution to seabirds by combining tracking data with existing knowledge. It highlights the accumulation of plastic pollution in the high seas, far beyond breeding areas, necessitating international cooperation to address marine plastic pollution from both maritime and land-based sources.
Approximately 22% of ocean litter is likely to originate from marine activities, emphasizing the importance of proper waste management to prevent plastic waste from entering the ocean. Strengthening compliance with the longstanding ban on discarding any form of plastic from ships (adopted in 1973) is crucial.
To safeguard seabirds and marine ecosystems, regional and global treaties must be established, covering plastic pollution in both national waters and the high seas. Only through large-scale implementation of solutions can we protect the diverse array of animals inhabiting our oceans.