Over 70pc of deep-sea fish have ingested plastic - study finds
MORE than 70pc of the deep water fish stock in the Northwest Atlantic have ingested plastic - one of the highest frequencies of microplastic in fish worldwide.
A new study, carried out by marine scientists at NUI, Galway found that 73pc of the monitored deep water fish from the Northwest Atlantic Ocean had ingested plastic particles.
Scientists from NUI, Galway carried out the research during a transatlantic crossing on-board the Marine Institute’s Celtic Explorer research vessel, taking dead deep sea fish from midwater trawls in the Northwest Atlantic Ocean.
The fish were taken from a depth of up to 600m and ranged in size from 3.5cm to 59cm. They included the Spotted Lanternfish, Glacier Lanternfish, White-spotted Lanternfish, Rakery Beaconlamp, Stout Sawpalate and Scaly Dragonfish.
Microplastics commonly breakdown from larger plastic items entering our oceans but also originate from waste water effluents carrying plastic fibres and microbeads from clothings and personal care products. Due to their low density, most of these microplastics float at the sea surface.
Lead author of the study Alina Wieczorek, a PhD candidate from the School of Natural Sciences and Ryan Institute at NUI Galway, said the fish were likely exposed to the microplastics when they migrate to the surface at night to feed.
"One of the inspected Spotted Lanternfish, which was 4.5cm in size, had 13 microplastics extracted from its stomach contents. The identified microplastics were mostly fibres, commonly blue and black in colour," he said.
"Some only measured 50 microns in length. In total, 233 fish were examined with 73pc of them having microplastics in their stomachs, making it one of the highest reported frequencies of microplastic occurrence in fish worldwide," she said.
The fish were sampled from a warm core eddy, which is thought to accumulate microplastics similar to ocean gyres. As a result the sampled fish may have originated from a particularly polluted patch of water.
While the ingestion of microplastics is known to cause internal damage to fish, scientists are now concerned that they also have associated additives, such as colourants and flame retardants, and these toxins can be transferred to animals that eat them with potential harmful effects.
Dr Tom Doyle, a co-author of the study from the Ryan Institute at NUI Galway, said: “While there is clearly a concern that the ingestion of microplastics with associated toxins may have harmful effects on these fishes, or even the fishes that feed on them, our study highlights that these seemingly remote fishes located thousands of kilometres from land and 600 metres down in our ocean are not isolated from our pollution.
"Indeed, it’s worrying to think that our daily activities, such as washing our synthetic clothes in our washing machines, results in billions of microplastics entering our oceans through our waste water stream that may eventually end up in these deep sea fishes."
The research, which is published today in the international journal Frontiers in Marine Science, was carried out within the PLASTOX project, a European collaborative effort to investigate impacts of microplastics in the marine environment under the JPI Oceans framework and supported by the iCRAG (Irish Centre for Research in Applied Geoscience) project, funded by Science Foundation Ireland.