New Research Finds Ocean Feeding Ground For Larval Fish Accommodates More Plastic Than Fish
The ocean feeding ground, which is crucial for baby fish, found to contain bits of plastic, even seven times more than the number of baby fish in nursery water, a team of researchers led by the National Oceanic and Atmospheric Administration found. They set out to investigate the roles of “slicks” as nursery habitats for tiny larval fish and learn more about their habits off Hawaii’s West Coast.
The slicks are occurring naturally. These ribbon-like, smooth water features of the oceans, are full of plankton, and an important food resource. The researchers expected the developing fish in surface slicks as that would also gather the plankton the fish rely on, and where they feed and grow, Vice explained. However, they found the slicks also gathered something else.
“We were finding more plastics than fish,” Jonathan Whitney, study co-leader and marine ecologist for the Joint Institute for Marine and Atmospheric Research in Honolulu, told HuffPost.
“We were shocked to find that so many of our samples were dominated by plastics,” said Dr Jonathan Whitney.
The researchers found that plastics in the slicks outnumbered fish by ratio seven is to one.
“It was completely unexpected,” Dr Gareth Williams of Bangor University, UK, told BBC News. “The fact that the plastics outnumber the larval fish was astonishing.”
A troubling picture, reflected by the results, was published in the Proceedings of the National Academy of Sciences Monday. The researchers found 12 times more plastic in the slicks compared to the amount of plastic recently recorded in the Great Pacific Garbage Patch, the Honolulu Star-Advertiser explained. The plastics found in the slicks were also 126 times denser than in the surrounding waters, and the majority were of a millimeter and even less, referred to in the study as “prey size.”
The hundreds of larval fish, when dissected, the researchers discovered that many fish species ingested plastic particles.
“It’s these tiny pieces that are being eaten by baby fish. It’s these tiny pieces that we can’t even see with our naked eyes that are the problem here,” Whitney told the Star-Advertiser.
There is enough evidence that plastic is being ingested by marine life, and out of more than 600 fish dissected, 48, or 8.6 percent, had ingested plastic. The plastic was found in seven out of eight fish families studied that include critical commercial species like swordfish and mahi-mahi. It was also evidenced in flying fish, which are a vital part of the marine food web.
“We found tiny plastic pieces in the stomachs of commercially targeted pelagic (open sea) species, including swordfish and mahi-mahi, as well as in coral reef species like triggerfish,” said Dr Whitney.
“The fact that larval fish are surrounded by and ingesting non-nutritious plastics, at their most vulnerable life stage, is certainly cause for alarm,” study co-leader and NOAA oceanographer, Dr Jamison Gove, of the Pacific Islands Fisheries Science Center in Honolulu told the Star-Advertiser.
“Biodiversity and fisheries production are currently threatened by a variety of human-induced stressors such as climate change, habitat loss, and overfishing,” said Dr Jamison Gove.
“Unfortunately, our research suggests we can likely now add plastic ingestion by larval fish to that list of threats.”
However, the health implications are unclear. How plastic will impact the developing fish exactly is yet to know. However, according to the prediction of the researchers, it could lower their chances of survival in addition to the other threats they already face from overfishing, habitat loss, and the climate crisis.
“If they’re eating plastics at their first critical meal, they’re filling their bellies with plastics instead of plankton,” Whitney told HuffPost.
“We don’t have the data to say whether or not this has a negative effect on fish populations,” said Dr Gareth Williams.
“But the fact that they’re eating these non-nutritious particles at the point when eating is so critical for their survival in those first few days, it can only be a bad thing.”