Fragments of plastic are found throughout the world, from nearly every continent to nearly every body of water.
Now, researchers have found 73 percent of Northwest Atlantic deep-sea fish are also eating it – the highest reported frequency of plastic-eating fish in the world.
Plastic pollution goes deep.
Using trawls 600 meters (1,970 feet) below the surface, researchers from the National University of Ireland (NUI) in Galway examined more than 230 dead deep-water fish, from the smallest glacier lanternfish measuring 3.5 centimeters (1.4 inches) to the largest stout sawpalate coming in at 59 centimeters (23 inches). The findings are published in Frontiers in Marine Science.
The fish were inspected for microplastics in their stomachs, like one tiny spotted lanternfish that had 13 microplastics extracted from it.
Microplastics are plastic fragments broken down from larger plastic items that come from all sorts of things used every day. Take, for example, the plastic that sloughs off your clothing in the wash, or the microbeads in your favorite face scrub.
A lot of these plastics make their way to the sea via drainage systems, where once at sea they float along the surface.
These mesopelagic fish, whose vertical migration through the water column transports carbon and nutrients to the deep sea, move up to the surface where they mistake the plastic for food.
“Deep-water fish migrate to the surface at night to feed on plankton and this is likely when they are exposed to the microplastics,” said lead author Alina Wieczorek in a statement.
Plastic can’t be digested, it just sits in an animal’s stomach and eventually blocks the digestive tract.
And these fish had a lot of plastic in their belly – one species had an ingestion rate of 100 percent. The samples were pulled from a warm core eddy, a circular current similar to ocean gyres thought to accumulate microplastics. The fish are thought to have originated from an especially polluted area in the Atlantic Ocean, hence the high rate.
“This would explain why we recorded one of the highest abundances of microplastics in fishes so far, and we plan to further investigate the impacts of microplastics on organisms in the open ocean,” said Wieczorek.
Plastics mostly came from blue and black microfibers found in synthetic materials like rayon, polyester, and nylon.
Previous studies show that microplastics can be ingested by all sorts of marine animals, from zooplankton to worms and fishes. In addition to obstructing the digestive system, ingesting plastic causes internal physical damage, inflammation of the intestines, and difficulties when eating. Of most concern is the additives (such as coloring or flame retardants) in plastics, which can be transferred to animals when they eat them.
The study was part of a bigger investigation into how microplastics impact key European marine species and ecosystems.