November 13, 2019 — Plenty of heartbreaking stories about turtles, seabirds and whales found dead with dozens of plastic bits in their stomachs have surfaced in recent years. But a new study reveals that it’s not just adult sea animals that are getting a gullet full of plastic. Larval fish are inundated with plastic fragments in their nursery habitats and they’re eating those pieces along with their natural food sources, according to the paper published in the journal PNAS.
The finding comes from a recent study looking at where baby fish spend their time. An international team of scientists joined up with NOAA’s Pacific Islands Fisheries Science Center to study an ocean habitat called surface slicks, or long lines of smooth water found paralleling coastlines that are created when internal ocean waves converge.
To do that, the team used remote sensing data to identify slicks along the coast of Hawaii then used tow surveys to scoop up plankton and larval fish in them. They found that larval fish prefer to congregate in slicks, which have lots of tasty zooplankton.
The team found the slicks have more eight times as many larval fish as surrounding waters and act as de facto fish nurseries for the first few months of a fish’s life cycle.
“We found that surface slicks contained larval fish from a wide range of ocean habitats, from shallow-water coral reefs to the open ocean and down into the deep sea—at no other point during their lives do these fish share an ocean habitat in this way,” says study co-author Jonathan Whitney, a NOAA marine ecologist, says in a press release. “Slick nurseries also concentrate lots of planktonic prey, and thereby provide an oasis of food that is critical for larval fish development and survival.”