Researching Microplastics

Meet ATU Galway Researcher Róisín Nash

As a marine biologist, I love to eat seafood and at the same time, I am particularly interested in enabling sustainability and conserving marine biodiversity.

My research explores the animals that live in, on or near our seabed, from the fish I eat to the amazing little creatures that they feed on. Overfishing, climate change and pollution, has meant that to conserve biodiversity I need to refocus my research on pressures such as microplastic pollution, their sources, pathways and fate.

What are Microplastics?

Microplastics are the smaller bits of plastic, smaller than the eraser on the top of a pencil, or as small as the thickness of a strand of hair. They are so prevalent that everywhere we have looked from the deep sea habitats off the Irish continental shelf (~3000m) to the many animals inhabiting our seas to the intertidal of Galway Bay our team has found them.

Where are Microplastics coming from?

It is thought that the predominant sources of plastics and microplastics in the marine environment comes from the agriculture sector (plastic seed coatings; spreading of sludges from wastewater treatment plants and the use of plastic mulching); the shipping industry (1816 containers lost at sea in 2020), and the fishing industry (abandoned, lost, and discarded fishing gear). We have found that levels of microplastic found along our coasts is influenced by riverine input, a major source, and that their pathway, distribution, and sink is often influenced by ocean currents.

What can we do?

The term ‘single use plastic’ is now familiar to most of us but are we prepared to avoid their purchase? Microplastics found in our oceans are largely fibres resulting from the washing of clothes, and the degradation of ropes and nets.

COVID-19 has seen the increase of plastic through single use PPE and hand sanitiser. As a society we need to ensure that masks are disposed of properly and the ear straps cut to avoid further harm through either ingestion or the entanglement of animals

Do we need to be careful when eating fish?

The Dublin Bay prawn is something most Irish people would have eaten or at least seen on a menu. Our research team, along with researchers at the Marine Institute, have found microplastics within their guts, most likely eaten along with their food.

If you have ever removed the shell, the gut is that black stringy bit you see run along the curve of the prawn. Most definitely removed by chefs but something to ensure you remove at home as this will also remove the microplastics.

Similarly, our team has found microplastics in the gut of fish and other species you find at your local fishmongers. Again, here the stomach, gut and microplastics will have been removed. There are some species, like the periwinkle, that we eat whole, lightly boiled directly from our shores without removing their guts. Thankfully these species located off the west coast of Ireland, have been found to contain very low levels of microplastics

Dr Róisín Nash is a lecturer and researcher in the Marine and Freshwater Research Centre (MFRC) at ATU Galway City whose research surrounds the societal issue of microplastics.