Coastal Organisms Thrive on Floating Plastic Debris in the “Great Pacific Garbage Patch
Coastal plants and animals have found a new way to survive in the open ocean—by colonizing plastic pollution. A new commentary published Dec. 2 in Nature Communications reports coastal species growing on trash hundreds of miles out to sea in the North Pacific Subtropical Gyre, more commonly known as the “Great Pacific Garbage Patch.”
“The issues of plastic go beyond just ingestion and entanglement,” said Linsey Haram, lead author of the article and former postdoctoral fellow at the Smithsonian Environmental Research Center (SERC). “It’s creating opportunities for coastal species’ biogeography to greatly expand beyond what we previously thought was possible.”
Gyres of ocean plastic form when surface currents drive plastic pollution from the coasts into regions where rotating currents trap the floating objects, which accumulate over time. The world has at least five plastic-infested gyres, or “garbage patches.” The North Pacific Subtropical Gyre, between California and Hawai’i, holds the most floating plastic, with an estimated 79,000 metric tons of plastic floating in a region over 610,000 square miles. While “garbage patch” is a misnomer—much of the pollution consists of microplastics, too small for the naked eye to see—floating debris like nets, buoys and bottles also get swept into the gyres, carrying organisms from their coastal homes with them.
The authors call these communities neopelagic. “Neo” means new, and “pelagic” refers to the open ocean, as opposed to the coast. Scientists first began suspecting coastal species could use plastic to survive in the open ocean for long periods after the 2011 Japanese tsunami, when they discovered that nearly 300 species had rafted all the way across the Pacific on tsunami debris over the course of several years. But until now, confirmed sightings of coastal species on plastic directly in the open ocean were rare.
For this discovery, Haram teamed up with Ocean Voyages Institute, a nonprofit that collects plastic pollution on sailing expeditions, and a pair of oceanographers from the University of Hawai‘i at Manoa. The oceanographers, Jan Hafner and Nikolai Maximenko, created models that could predict where plastic was most likely to pile up in the North Pacific Subtropical Gyre. They shared that information with Ocean Voyages Institute.
One advantage of the institute, Haram—now a fellow at the American Association for the Advancement of Science—pointed out, is the low carbon footprint of its vessels. “It can take a lot of energy to get out to the middle of the ocean with a gas-powered boat,” she said. “So they use large-cargo sailing vessels to go around and remove plastics from the open ocean.”