A new study on seabirds has come to a disturbing conclusion: Their bellies are filled with plastic. Up to 90 per cent of marine birds alive today may have ingested plastic, and by 2050, that number could be as high as 95 per cent.
On Christmas Island in the Indian Ocean a red-footed booby stands amid plastic debris. Picture: Britta Denise Hardesty
"This is a huge amount and really points to the ubiquity of plastic pollution," said Chris Wilcox, lead author of a new scientific paper which appears this week in the Proceedings of the National Academies of Sciences.
Plastic is a hallmark of modern society, but it's also an ecological blight. Studies have estimated that there could be up to 580,000 fragments of bags, bottle caps and plastic fibres per square kilometre of ocean. And we've all heard tell of the Great Pacific Garbage Patch, a disgusting vortex of LEGOs, toothbrushes, synthetic cushions and other non-degradable waste products spanning a region larger than Texas. Despite these alarming realities, few studies have attempted to track the movement of plastic into the marine food chain.
In their paper, the researchers reviewed previous literature on avian plastic ingestion rates, published between 1962 and 2012. Within these studies, an average of 29 per cent of birds had plastic in their gut. But using computer models that factor in avian ranges and plastic debris distributions, the researchers were able to show that up to 90 per cent of marine birds could have plastic in their gut, were those same studies conducted today.
When birds ingest large chunks of plastic — study co-author Denise Hardesty recalls opening up birds, only to find entire glowsticks, balloons, cigarette lighters and toys inside — they face a swift and painful death. More often, birds will swallow very small plastic fragments, but these can still have health impacts. As pointed out in the study, plastics can concentrate organic pollutants to levels a million times greater than those found in surrounding seawater. The toxicological effects of this aren't well understood.
An installation by artist Alejandro Duran highlights the plastic-filled state of our oceans.
But it's high time we start investigating those health impacts further, because the plastic problem is only getting worse. Our global plastic output is increasing exponentially, with production rates doubling every 11 years. That means that between 2015 and 2026, humans will produce as much plastic as we have since plastic manufacturing began. It's virtually guaranteed that a large fraction of that new plastic will make its way into the ocean, and into marine life.
"Projecting patterns in the literature forward using our fitted regression models, we predict that plastic will be found in the digestive tracts of 99% of all seabird species by 2050 and that 95% of the individuals within these species will have ingested plastic by the same year," the authors write. (And there's no reason to think this issue is limited to avians: A recent report for the UN Convention on Biological Diversity documented over 600 species, from microbes to whales, that are affected by plastic waste.)
Fortunately, there's a pretty straightforward solution: Stop using so much damn plastic. Bring reusable bags to the grocery store. Recycle everything you can. Only toss plastic in the garbage as a last resort.
"Even simple measures can make a difference," Hardesty said. "Efforts to reduce plastics dumped into the environment in Europe resulted in measurable changes in plastic in seabird stomachs in less than a decade. This suggests that improvements in basic waste management can reduce plastic in the environment in a really short time."