Cook’s petrel, a vulnerable species, had one of the highest plastic exposure risk scores in the study
Paul Donald
Endangered seabirds spend days and sometimes weeks foraging for food around floating ocean garbage dumps, according to a major study warning that international action to tackle plastic pollution is urgently needed.
The study used tracking data from more than 7,000 birds, combined with plastic pollution location data, to map the plastic exposure risk of 77 species of fulmar, a group of migratory seabirds.
It found that 25 percent of all seabird plastic exposure occurs outside of national jurisdictions, primarily in huge floating pollution patches such as the Great Pacific Garbage Patch.
Birds can spend hours to weeks foraging for food in these pollution hotspots, says team member Bethany Clark at the charity BirdLife International.
“They spend less time during the breeding season [at pollution hotspots] because they have to go back to feed their chicks. But that can still be many hours, and then they can spend weeks in the non-breeding season,” she says.
Previous studies have shown that plastic can enter the stomachs of seabirds, causing blockages and poisoning. Petrels have also been shown to regurgitate plastic pollution to feed their chicks.
Worryingly, some of the most endangered birds, such as shearwaters and Hawaiian storm petrels, are among the species most exposed to ocean plastic.
“It is concerning to us that some of these truly endangered species also suffer from having to feed in plastic-rich areas,” says Clark.
As much of plastic exposure occurs outside of national jurisdictions, Clark is calling on countries to work together on global solutions to address the sources of pollution.
Tackling plastic waste from fishing vessels and reducing the use of single-use plastics would be effective first steps, she says.
Countries are also working as part of the United Nations process to create a global, legally binding treaty to curb plastic pollution, which could come into effect from 2025.
The study only looked at the exposure risk the birds faced, rather than assessing how much plastic was actually ingested by different populations and species.
That’s an area for future research, says team member Lizzie Pearmain at the University of Cambridge. “For future studies, if we find that two different populations are ingesting more or less plastic than expected just from the spatial overlap, then we can begin to understand whether they are actively avoiding it or are more likely to ingest it,” she says. .
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