Study Confirms Global Threat of Plastic Pollution to Seabirds

It’s no secret that plastic pollution is a major problem. Research has revealed that it makes its way to incredibly remote areas, and now a new study looks at how it is threatening the lives of seabirds even in uninhabited areas.

In findings published in the journal Aquatic Conservation: Marine and Freshwater Ecosystems, researchers looked at plastic collected from far corners of the South Pacific Ocean, including nesting locations of New Zealand albatrosses.

They found that plastic travels incredibly long distances in the ocean, affecting birds as they forage and nest.

Study co-author Paul Scofield, senior curator natural history at Canterbury Museum in Christchurch, New Zealand, and his team had worked in the late 1990s and 2000s collecting pieces of plastic from albatross nesting sites on the Chatham Islands in the South Pacific Ocean. The birds had swallowed most of the plastic while foraging at sea and then regurgitated it in their nests when trying to feed their chicks.

“Some of the areas were very remote indeed. The Chatham Islands, where we collected plastics from albatross nesting sites, are 650 kilometers [404 miles] east of New Zealand,” Scofield tells Treehugger. “Although the main islands have a small human population, the tiny islands where the albatross nest are completely uninhabited.”

The researchers also examined plastic from the stomach contents of diving seabirds killed by the fishing industry around the Chatham Rise, a large underwater plateau east of New Zealand, and along the southeast coast of the South Island. In all, researchers studied plastic interaction with eight seabird species from the South Pacific Ocean.

“Seabirds travel the whole pacific from the Antarctic ice edge to the Arctic ice edge,” Scofield says. “They are the most efficient sampling system ever. No comparable human method of sampling the oceans has or will ever be invented.”

Color Matters

For the study, the researchers then compared these items with similar plastics found from other locations around the Pacific. They analyzed the types of plastic, including their color, shape, and density.

They found that albatrosses are more likely to dine on red, green, blue, and other brightly-colored plastics because they probably mistake these items for prey. The researchers suggest that commercial fishing gear could be the source of some of the plastic found at nesting sites.

Diving seabirds like the sooty shearwater (Ardenna grisea) primarily had hard, white and gray, round plastic in their stomachs. The researchers believe that the birds swallowed these plastics accidentally when they ate fish or other prey that had first ingested the plastics.

Earlier studies have found that even when plastic ingestion doesn't kill birds, it can have an overall impact on their health and growth, including body mass, wing length, and head and bill length.

"Plastic is everywhere," Scofield says. "Seabirds are eating more and more plastic and it is affecting their reproduction and fitness."

The takeaway from the study is simple, Scofield says.

“This is a global problem,” he says. “Avoid plastic if possible. If not reduce, reuse and recycle.”