A new study has found microplastics to be present in the gut of almost three quarters of deep sea fish, leading to fears that levels of ingestion are higher than previously thought.
Researchers from National University of Ireland Galway found that 73% of deep water fish in the Northwest Atlantic had ingested plastic particles, one of the highest frequencies ever reported in the marine environment.
Microplastics, which can be small pellets found in consumer goods or fragments of larger plastic items such as bags, have been found in marine environments around the globe with an ever increasing distribution in recent decades. However, previous studies have reported significantly lower occurrence rates of 11% in the North Atlantic and 9% and 35% in the North Pacific Gyre regions.
The researchers, who published their findings in the journal Frontiers in Marine Science, said the variance could be explained by a lack of standardised methods for the extraction of microplastics from gastrointestinal tracts of fish, or due to differences in the abundances of microplastics found in the study areas.
They added that such high numbers of microplastics in the gut contents of fish were of great concern due to their detrimental impact on species and ecosystems. Deep sea fish provide an important food source for many large predators such as dolphins, seals, and tuna as well as sea birds and are also responsible for a significant amount of carbon and nutrient cycling.
Little is known of the impact of human consumption of microplastics via seafood on public health. The government is in the process of reviewing the impacts on health of several types of pollution including microplastics.