A net dragged through an ocean slick off Hawaii Island caught this scribbled filefish, about 50 days old and five centimeters long, and all sorts of plastics. DAVID LIITTSCHWAGER

Plastics outnumber baby fish 7-to-1 in some coastal nurseries

Calm ocean surface nurseries shelter thousands of baby fish. They also attract bits of plastic

Plastics can enter the food web at an unexpected point: larval fish as small the tip of a pencil.

Larval fish congregate in ocean slicks — ribbons of calm water that form naturally on the ocean’s surface — to feast on an abundance of prey. Prey-sized plastics also accumulate in these fish nurseries, outnumbering the fish 7-to-1 and ending up in the stomachs of many, researchers report online November 11 in the Proceedings of the National Academy of Sciences.

A larval fish (flying fish, top; triggerfish, bottom) collected in an ocean slick off the coast of Hawaii Island. In this composite, they’re situated near plastic fragments they had ingested. A dime is shown for scale.J. WHITNEY/NOAA FISHERIES

“This is perhaps the most vulnerable life stage of pelagic fish,” says Anela Choy, a biological oceanographer at the Scripps Institution of Oceanography in La Jolla, Calif., who wasn’t involved in the study. She has documented plastic accumulation in the deep sea (SN: 6/6/19), and says this new study raises important questions about the effects of plastic ingestion at such a fragile life stage.

The researchers set out to study larval fish, not plastics, says Jonathan Whitney, a marine ecologist for the National Oceanic and Atmospheric Administration in Honolulu. After eggs hatch, tiny fish just a few millimeters in length spend their first days to weeks feeding and growing at the ocean surface before returning to their natural habitat. But “we know very little about where they go, what they eat, and how they find their way back home,” Whitney says.

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