In the ocean, plastic attracts other toxic substances to it, becoming all the more dangerous for marine and human health, said a panel of marine biologists and toxicologists at the Monterey Bay Aquarium’s Sustainable Food Institute in Monterey, Calif.
“Once in the ocean, plastic is like a magnet for toxins. It concentrates the surrounding toxins,” said Dr. Chelsea Rochman, assistant professor at the University of Toronto and UC Davis in marine ecology and ecotoxicology. “In some cases, PCBs (polychlorinated biphenyls) have been concentrated at 1 million times the rate of the surrounding waters.” When plankton ingests that plastic, with all its additionally collected chemicals, and other fish eat the plankton, the toxins move up the food chain to humans.
In one study, Rochman and her colleagues found plastic in the guts of one-in-four fish sampled in San Francisco and Indonesia. The Californian fish were contaminated with microbeads, extremely small pieces of plastic used in cosmetics and bodycare products. The Indonesian fish, on the other hand, didn’t have any microbeads in them, but contained other signs of plastic that had likely escaped the local trash system.
Some studies have shown that the contaminants in the plastic can pass to the fish, said Rochman. Plastic can also disrupt the animal’s ability to reproduce, putting the future of a species at risk.
The scope of the plastic problem is daunting. The Pacific garbage patch — a huge swirling mass of plastic in the ocean — has gained a lot of attention, but there are actually five other massive gyres of trash, one in every ocean. And altogether “they only represent 5 percent of all the plastic in the ocean today,” said Dr. Letise LaFeir, California Ocean Policy Manager at the Monterey Bay Aquarium. At the current rate, scientists expect there to be more trash in the ocean than fish by 2050.
Dr. Rolf Halden, professor of Sustainable Engineering and the Built Environment at the Arizona State University, said that plastic itself isn’t the problem; it’s poorly designed plastics that rely on carcinogens and hormone disrupting chemicals. “There is a laundry list of chemicals in our bodies,” he said. “We are living in today’s world with yesterday’s chemistry.”