In deep-sea starfish the microplastic ingestion level found was similar to those of coastal water creatures. (Photo: SAMS)
Marine microplastics first time quantified in deep sea invertebrates
Wednesday, August 23, 2017, 00:50 (GMT + 9)
Researchers at the Scottish Association for Marine Science (SAMS) in Oban, Scotland, have found that around half of marine creatures living at depths of more than 2,000 metres in the North Atlantic could be eating microplastic material.
To reach this conclusion, these scientists sampled deep-sea starfish and sea snails from the Rockall Trough and found microscopic traces of plastic in 48 per cent of those sampled. The levels of plastic ingestion were comparable to those found in species living in shallower coastal waters.
Although scientists have previously found traces of microplastics in the deep sea, this research is the first time microplastic ingestion in deep-sea invertebrates has been quantified.
SAMS scientists identified a range of plastics. The paper shows how even naturally buoyant substances, such as polyethylene used to make plastic shopping bags, could be found inside brittle stars, sea stars and sea snails.
Polyester was the most abundant plastic identified, mainly in the form of microscopic fibres, and while it is not possible to definitively know its origin, this substance is used widely in clothing and can reach the sea in waste water from washing machines.
The study lead author Winnie Courtene-Jones, a University of the Highlands and Islands PhD researcher based at SAMS, pointed out: “Microplastics are widespread in the natural environment and present numerous ecological threats, such as reducing reproductive success, blocking digestive tracts and transferring organic pollutants to organisms which eat them. More than 660 marine species worldwide are documented to be affected by plastics."
The scientist stressed that there is much evidence of microplastics around coastal waters but little is known about the extent of plastic pollution in the deeper ocean and that the deep sea is the largest, but also the least explored part of the planet, highliting that it may be the final sink for plastics.
For his part, SAMS deep sea ecologist Dr Bhavani Narayanaswamy, said: “No longer ‘out of sight, out of mind’, research into microplastics is rapidly increasing in importance. We are attempting to establish not only how widespread they are, but also how and where they accumulate in animals, and ultimately the impact that they may have on the health of humans."
He commented that SAMS is increasing its research into microplastics, with two new PhD students joining the team in October; one to look at microplastics in the Scottish marine environment, comparing urban and rural locations, whilst the second student will be attempting to develop airborne sensors that will detect microplastics.
The paper Microplastic pollution identified in deep-sea water and ingested by benthic invertebrates in the Rockall Trough, North Atlantic Ocean was published in the journal Environmental Pollution.