A new study estimates that 90 percent of individual seabirds alive today have consumed some form of plastic.
“This is a huge amount and really points to the ubiquity of plastic pollution,” says lead author Chris Wilcox, a senior research scientist at Australia’s Commonwealth Scientific and Industrial Research Organisation (CSIRO) Oceans and Atmosphere Flagship.
Wilcox also contributed to a study published earlier this year that found more than 4.8 million metric tons of plastic waste enters the oceans from land each year. The same working group at University of California, Santa Barbara’s National Center for Ecological Analysis and Synthesis (NCEAS) conducted both studies, which the Washington, DC-based Ocean Conservancy supported.
“We’ve known for some time that the magnitude of plastic pollution is daunting,” says NCEAS director Frank Davis. “This study is important in revealing the pervasive impact of that plastic on seabirds.”
Red flag for the ecosystem
The researchers found that nearly 60 percent of all seabird species, including albatrosses, shearwaters, and penguins, have plastic in their guts.
According to coauthor Denise Hardesty, seabirds are excellent indicators of ecosystem health. “Finding such widespread estimates of plastic in seabirds is borne out by some of the fieldwork we’ve carried out where I’ve found nearly 200 pieces of plastic in a single seabird,” she says.
The investigators’ analysis of studies published since the early 1960s shows that plastic is increasingly common in seabirds’ stomachs. In 1960, plastic was found in the stomachs of less than 5 percent of seabirds; by 2010 that figure had risen to 80 percent. Based on current trends, the scientists predict that plastic ingestion will affect 99 percent of the world’s seabird species by 2050.
The plethora of plastic comes from bags, bottle caps, and plastic fibers from synthetic clothes that have washed out into the ocean from urban rivers, sewers, and waste deposits. Birds mistake the brightly colored items for food or swallow them by accident, causing gut impaction, weight loss, and sometimes death.
Improvement is possible
According to the study, plastics will have the greatest impact on wildlife that gather in the Southern Ocean in a band around the southern edges of Australia, South Africa, and South America. These areas are home to widely diverse species. While the infamous garbage patches in the middle of the oceans have higher densities of plastic, fewer birds live in these regions so the impact is reduced.
Hardesty, who works with Wilcox at CSIRO Oceans and Atmosphere, notes that the opportunity still exists to change the impact plastic has on seabirds. “Improving waste management can reduce the threat plastic is posing to marine wildlife,” she says.
“Even simple measures can make a difference,” Hardesty adds. “Efforts to reduce plastics dumped into the environment in Europe resulted in measureable 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.”
The work took place as part of a national marine debris project supported by CSIRO and Shell’s social investment program as well as the marine debris working group at UCSB’s NCEAS. Erik van Sebille of the Grantham Institute at Imperial College London is also a coauthor. The findings appear in the Proceedings of the National Academy of Sciences.
Source: UC Santa Barbara