Aug. 19 (UPI) -- Sea birds regularly mistake bits of plastic for natural food, putting them at risk of physical harm -- they can choke on debris and it can also cause intestinal blockage.
But new research -- published Wednesday in the journal Frontiers in Environmental Science -- suggests plastic pollution can also poison sea birds, leaching toxins into the stomachs of birds that ingest plastic.
To better understand the toxic threat posed by plastic pollution, researchers surveyed the chemical composition of stomach oil of northern fulmars, an abundant subarctic seabird. Hunters on the Faroe Islands collect the nutrient-rich oil.
"I've been working on northern fulmars for almost 10 years," lead study author Susanne Kühn said in a news release.
"As these seabirds ingest plastics regularly, and 93 percent of the fulmars from the North Sea have some plastic in their stomachs, it is important to understand the potential harm this could cause," said Kühn, marine biologist at Wageningen Marine Research in the Netherlands.
Researchers combed the beach for a variety of plastic types and shapes that a northern fulmar might eat. Scientists incubated their plastic haul in the stomach oil under realistic conditions in regards to temperature and agitation.
Periodic testing during the three-month incubation confirmed a variety of toxins were leached into the stomach oil, including plasticizers, flame retardants and stabilizers.
Even before scientists placed the plastic in the oil, tests confirmed the stomach oil, which was collected from northern fulmar chicks, contained trace amounts of plastic-derived chemicals.
Scientists aren't yet sure how these toxins impact the health of seabirds, but previous studies suggest some of the chemicals could affect the endocrine system, which controls the release of hormones. Researchers suggest the toxins could also trigger genetic mutations.
"I hope that these results will increase awareness of the various negative effects of plastic debris in the oceans," said Kühn. "We urgently need to reduce the amount of plastic in the marine environment."