Common Irish crustacean is churning out nanoplastics at alarming rate

30 Jul 2020

Image: © Gabriel/

UCC researchers have found that a common creature in Irish streams is munching on microplastics and producing even smaller nanoplastics.

While the effects of microscopic particles of plastic in the world’s oceans and waterways have been well documented, researchers from University College Cork (UCC) have now helped create a clearer picture of one source of nanoplastics in freshwater rivers, streams and lakes.

Writing in Scientific Reports, the researchers showed that microplastics smaller than 5 millimetres in size in Ireland’s streams are being broken down into even smaller nanoplastics at least five thousand times smaller.

In a surprising discovery, they found that the source of these nanoplastics was a freshwater invertebrate animal that is able to break down microplastics in a matter of hours. Until now, it was thought the breakdown occurred very slowly by materials being exposed to sunlight or wave action.

“We have found that the freshwater amphipod, a small crustacean, called Gammarus duebeni is able to fragment microplastics into different shapes and sizes, including nanoplastics, in less than four days,” said UCC’s Dr Alicia Mateos-Cárdenas, who led the study.

“Whilst this species lives in Irish streams, they belong to a bigger animal group of invertebrates commonly found around the world in freshwaters and oceans. Our finding has substantial consequences for the understanding of the environmental fate of microplastics.”

Images of the crustaceans and nanoplastics inside their guts.

(Top) The freshwater amphipods Gammarus duebeni and their plant food source Lemna minor. (Bottom left) Two fragmented microplastics in an amphipod’s gut. (Bottom right) A nanoplastic fragment inside an amphipod’s gut. Image: Alicia Mateos-Cárdenas.

Calls for further research

While microplastics can become stuck in the gut of seabirds and fish, current understanding suggests that smaller nanoplastic particles could penetrate cells and tissues where their effects could be much harder to predict.

Mateos-Cárdenas and the researchers said this discovery is particularly worrying given that such a common invertebrate animal can rapidly produce vast numbers of nanoplastics.

“These invertebrates are very important in ecosystems because they are prey for fish and birds, hence any nanoplastic fragments that they produce may be entering food chains” Mateos-Cárdenas added.

“The data in this study will help us to understand the role of animals in determining the fate of plastics in our waters, but further research is urgently needed to uncover the full impact of these particles.”

Colm Gorey was a senior journalist with Silicon Republic