The Ocean Conservancy's Dr. Erin Murphy Documents the Lethality of Ocean Plastics

Each year, over 11 million metric tons of plastic end up in the ocean, which is like dumping a garbage truck full of plastic every minute. For years, we’ve known that marine animals eat this debris, but no one had measured exactly how much plastic it takes to kill them. Dr. Erin Murphy, who leads ocean plastics research at the Ocean Conservancy, is the principal author of a major study published in the Proceedings of the National Academy of Sciences. Her team analyzed more than 10,000 necropsies from 95 species of seabirds, sea turtles, and marine mammals worldwide. Earth911’s summary describes this critical study, which found lethal plastic thresholds that could change how we view the plastic crisis.

The study measured how deadly different types of plastic are to sea life, which makes the results especially useful for policymakers. Each finding suggests a clear policy action, such as banning balloon releases like Florida has done, banning plastic bags as in California’s SB 54, or improving how fishing gear is marked and recovered. Still, Erin points out that focusing only on certain plastics is not enough. Her team found that even small amounts of any plastic can be dangerous. As she says, "At the end of the day, there is too much plastic in the ocean," and we need big changes at every stage of the plastics life cycle, from production to disposal.

There's encouraging evidence that interventions work. Communities in Hawaii conducted large-scale beach cleanups and saw the Hawaiian monk seal population rebound. A study published in Science confirmed that bag bans reduce plastic on beaches by 25 to 47%. And Ocean Conservancy's International Coastal Cleanup, now in its 40th year, removed more than a million plastic bags from beaches last year. These actions address a parallel crisis in human health that is building from the same pollution source. Most of the microplastics now found in humans and around the world began as the same macroplastics that are killing puffins and turtles. As Erin puts it, "I do view this all as part of the same crisis."

You can read the full study at pnas.org and learn more about Ocean Conservancy's work at oceanconservancy.org.