A study carried out by marine scientists at NUI Galway found that 73 per cent of deep sea fish had ingested microplastics. The study was undertaken in the Northwest Atlantic Ocean and the results published in the journal Frontiers in Marine Science.
The study consisted of a transatlantic crossing during which scientists took deep sea fish from midwater trawls from a depth of up to 600m. Some of the fish included potted Lanternfish, Glacier Lanternfish, Rakery Beaconlamp, Stout Sawpalate and Scaly Dragonfish. The fish were inspected upon return.
Alina Wieczorek, lead author of the study and PhD candidate from the School of Natural Sciences and Ryan Institute at NUI Galway, said: “Deep water fish migrate to the surface at night to feed on plankton (microscope animals) and this is likely when they are exposed to the microplastics. One of the inspected Spotted Lanternfish, which was 4.5 centimetres in size, had 13 microplastics extracted from its stomach contents. The identified microplastics were mostly fibres, commonly blue and black in colour. Some only measured 50 microns in length. In total, 233 fish were examined with 73% of them having microplastics in their stomachs, making it one of the highest reported frequencies of microplastic occurrence in fish worldwide.”
Microplastics are the result of larger plastic items breaking down over time or the result of small plastics being washed (such as in clothing) and the effluent then being released into the sea.
While other studies have also arrived at the same conclusion, this study hightlights that even in mid ocean and deep water, the effects of human pollution and plastics is finding its way into the food chain. Animals that eat these fish are likely to also become contaminated and it is only a matter of tracing the food chain until the plastics are ingested by humans.