Seabird Death Linked To Plastic Ingestion
There is no doubt that we’re facing a global plastic pollution crisis. The 250,000 tons of marine debris which currently float in our oceans provide obvious evidence. Not only does this put humans at risk, but it also endangers marine wildlife. Seabirds like petrels and albatrosses are especially under threat: They eat pieces of plastic because they look like food to them, which can cause them to die.
At the moment, seabird populations are dwindling: For nearly half of seabird species, the number of specimens is decreasing, and 28% of species are already endangered. Can this be linked to the animals’ plastic consumption?
To answer this question, researchers looked at the relationship between consumed plastics and death in seabirds. They examined 1733 dead marine birds in Australia and New Zealand, and sorted them into three groups: dead from having eaten marine plastics (22), death not related to plastic consumption (1265), and unknown death (446).
In the birds who died from having eaten marine plastics, the research team found more plastic debris than in the birds from the other two categories. The more debris an animal had consumed, the greater was the risk of mortality.
If a bird had ingested only a single item of marine plastic, they would already have a 20.4% increased chance of dying. Still, not all debris poses the same risk: Soft plastics –balloons specifically– in the gastrointestinal tract were most likely to lead to death, 32 times more likely than hard plastics to be precise. The researchers think that birds probably mistake balloons for prey when they forage, because they look like squid.
The researchers therefore suggest the development of policies that effectively cut down the plastic debris in our oceans, to help seabirds and other marine animals survive. Reducing the presence of balloons and balloon fragments especially would help to make a positive impact: Without those, 23% of the birds examined in this study wouldn’t have died.