ALMOST THREE QUARTERS of 233 deep water fish from the Northwest Atlantic Ocean studied by researchers from NUI Galway have ingested plastic particles.
It’s one of the highest reported frequencies of microplastic occurrence in fish around the globe.
As part of the study the NUI Galway scientists participated in a transatlantic crossing on-board the Marine Institute’s Celtic Explorer research vessel.
During this research cruise they studied dead deep sea fish from midwater trawls in the Northwest Atlantic Ocean. The fish were taken from a depth of up to 600 metres using large fishing nets.
The fish ranged in size from smaller species like the Glacier Lantern, measuring at 3.5 centimetres, to the largest species, the Stout Sawpalate (59 centimetres).
Upon return to Galway, the fish were inspected for microplastics in their stomach contents.
“Deep water fish migrate to the surface at night to feed on plankton and this is likely when they are exposed to the microplastics,” Alina Wieczorek, lead author of the study, said.
“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 small plastic fragments that commonly originate from the breakdown of larger plastic items entering our oceans.
Other sources may be wastewater effluents carrying plastic fibres from clothing and microbeads from personal care products. Due to their low density, most of these microplastics float at the sea surface.
Previous studies have shown that microplastics can be ingested by numerous marine animals from zooplankton, to worms and fish. The ingestion of microplastics by these animals may cause internal physical damage, inflammation of intestines, reduced feeding and other effects, according to the study’s authors.
However, what is also of concern is that many of these ingested microplastics have associated additives, such as colourants and flame retardants that are added to plastics during production process, and/or pollutants that are adsorbed onto the microplastics from the sea. There is now evidence that some of these toxins on the microplastics can be transferred to animals that eat them with potential harmful effects.
The study is published in the latest edition of Frontiers in Marine Science.