Animals Are Migrating to the Great Pacific Garbage Patch
The oceanic soup of plastic fragments is becoming a new kind of ecosystem.
The Great Pacific Garbage Patch does not seem like it would be a hospitable place. It is more than 1,000 miles from the nearest streak of land. The sun is brutal and unrelenting there, the waters nutrient poor. There is nothing much to see except the eponymous garbage.
But look more closely at this plastic garbage, as scientists did recently, and you’ll find plenty of life: sea anemones as small as a pinky nail or as large as the palm of your hand; white, lacelike bryozoa; hydroids sprouting like orange feathers; shrimplike amphipods; Japanese oysters; mussels. None of these creatures belongs here. They are all coastal animals, adapted to the turbulent, nutrient-rich shores where water meets land, but they have all somehow learned to survive in the open sea, clinging to plastic.
According to a new study, these animals are now living side by side in the Great Pacific Garbage Patch with creatures that normally inhabit the middle of the ocean. Coastal and open-sea ecosystems are blurring together into a single, plastic-bound one. “As humans, we are creating new types of ecosystems that have potentially never been seen before,” says Ceridwen Fraser, a biogeographer at the University of Otago, who was not involved in the study. The Garbage Patch, far from being some barren wasteland, is the site of an active experiment in biology.
The scientists behind this study were originally intrigued by debris from the 2011 Japanese tsunami: Even after six years, debris was still washing up in the U.S. laden with creatures native to the Japanese coast. The scientists counted more than 60 species of mollusks alone. If coastal creatures could survive a six-year ocean crossing on plastic, how much longer could they survive? Could they be living on the high seas permanently? Ocean currents tend to trap floating objects in one of five gyres around the world, the most infamous of which is the Great Pacific Garbage Patch, between California and Hawaii. If coastal animals have found a new, plastic-based home anywhere in the open ocean, it would be here.
The “patch” is less a solid island of trash than a soupy swirl of debris ranging from microscopic pieces of plastic to larger objects such as fishing nets and buoys. Getting there is not easy, because it is so far from land. The scientists teamed up with the Ocean Cleanup, a nonprofit that was testing technology for removing trash from the gyre, to collect and freeze 105 pieces of garbage. Linsey Haram, then a postdoctoral fellow at the Smithsonian Environmental Research Center, remembers traveling to a California port in late 2018 to pick up trash bags full of nets, bottles, buoys, flower pots, clothes hangers, and buckets. She and her colleagues found coastal species on 70.5 percent of the debris. “We expected to find some; we just didn’t expect to find them at such frequency and diversity,” Haram told me. These migrants were not a minor part of the Great Pacific Garbage Patch ecosystem.
On two-thirds of the objects—essentially tiny floating islands—animals native to coasts were living side by side with animals native to the open ocean. They were smashed together into a single ecosystem and even a single food chain; for example, Haram told me, the coastal sea anemones were eating sea snails. The team also found evidence of the animals reproducing: The anemones were budding off tiny baby anemones, and some of the female crustaceans carried little broods of eggs. This suggests that they have taken up permanent residence and aren’t just eking it out temporarily.
Scientists call the ocean surface where water meets sky the “neustonic” or “neustic” habitat. Long before the advent of plastics, this habitat was dominated by natural objects such as kelp, wood, and pumice, on which life could gain a floating toehold. But these were relatively ephemeral. The influx of man-made plastics into the ocean might be “dramatically expanding a long-existing but previously minor habitat,” David Barnes, a marine ecologist with the British Antarctic Survey, told me in an email. It could also change the neustonic habitat in unpredictable ways: Some of the species that once drifted on organic matter, for example, might make the switch to living on plastics better than others. Scientists previously found that a marine insect named Halobates sericeus might actually be benefiting from the abundance of material in the Great Pacific Garbage Patch. It once had to lay its eggs on the rare floating feather or pumice stone; now it can just use plastic.
The waters around the plastic in the Garbage Patch are teeming with floating life too: Portuguese man o’ wars, blue sea dragons, tiny blue hydrozoans evocatively named by-the-wind sailors. Unlike coastal species that need to hitch a ride on something else, these floating animals likely bobbed here on their own via ocean currents. Little is known about many of them or how the proliferation of tiny plastic islands is affecting them. “We’re trying to learn really basic stuff,” says Rebecca Helm, an ecologist at Georgetown University who has cataloged these creatures in the Great Pacific Garbage Patch. Cleaning up the plastic around them is not straightforward: Attempts to collect floating debris, she has written, might entrap and threaten these species.
Many of the Garbage Patch objects that Haram and her collaborators found covered with coastal animals come from the fishing industry: nets, buoys, ropes, crates, eeltrap cones. These items last so long in the ocean, she pointed out, precisely because they are engineered to last a long time in seawater. They are part of an industry that has destroyed ocean ecosystems by removing billions of fish and shellfish from their home. Its plastic remnants are now also disrupting old ways of life in the ocean, creating new ways that we never intended and cannot yet imagine.