Predatory fish from the offshore waters around Hawaii have been ingesting a surprisingly large amount of plastics and other marine debris. This was found as part of a study conducted by scientists at the University of Hawaii at Manoa,
The scientists who, over a six year period, investigated the stomach contents of 595 fish representing 10 predatory open-ocean species, including commercially valuable tunas and billfishes, found that seven of the 10 species had ingested some form of debris, with varying degrees of frequency.
These observations are the first of their kind in scope and number, and they suggest that more attention need to be given to marine debris in subsurface waters, as well as to the potential food web implications for human consumption.
Looking at two different species of opah (moonfish), which are commonly eaten around the world, researchers found that 58 percent of the small-eye opah and 43 percent of the big-eye opah had eaten some kind of plastic debris.
Additionally 40 percent of the long-nosed lancetfish had consumed debris. The findings inidicate that fish all along the food chain ingest some form of plastic pollutants.
The most surprising fact revealed in the research was that the fish which ingested debris were all deep water species. A scientist justified this stating that “deep water fishes may have been coming up close to the surface to ingest debris, which is an unusual and unexpected behavior”.
It is not known whether the toxins are transmitted to the fish that consumes plastic, or ultimately to humans who consume the fish.