Ireland’s continental shelf awash with microplastics, and it’s increasing

8 Sep 2017

Image: photosthai/Shutterstock

A new survey into the amount of microplastics in Irish waters has found that not only are they abundant, but they are actually increasing.

Ireland’s waters might look nice and blue, but put them under the microscope and you’ll see a continental shelf that is awash with tiny plastic particles, otherwise known as microplastics.

These plastic beads (typically measuring less than 0.5mm in size) are the result of plastic pollution in oceans being broken down over time, but their damaging effects on marine life eventually find their way back to us.

According to a new survey conducted by researchers from NUI Galway, a study of Ireland’s western continental shelf found that a shallow layer of microplastics has formed along the Irish seafloor within marine sediments and their overlaying bottom waters.

More worryingly, it found that microplastic contamination is present along the shelf regardless of proximity to densely populated areas.

Looking specifically within Galway Bay, the team analysed sediment in the area and discovered that microplastic deposition is increasing over time.

The majority of the recovered material is categorised as secondary microplastics, suggesting they broke down from larger items, 85pc of which were fibres and 15pc broken fragments.


A subset of recovered microplastics at a magnification of between 40 and 50 times. Image: Martin et al, 2017

The range of polymer types, colours and physical forms recovered, the team said, suggests a variety of sources that may originate from plastic polymer fishing gear or land-based contributions from nearby industry, water treatment plants or households.

For researchers, an understanding of the distribution and accumulation of this form of pollution is crucial for gauging environmental risk, and has already become a major source of research, as seen at last January’s BT Young Scientist and Technology Exhibition.

This is down to the worrying news that keeps coming from other researchers across the globe, showing that human-made pollution has reached as far down as the Marianas Trench, which measures 10,000km deep.

Dr Audrey Morley, senior author of the study, said of the findings: “Our results show that the Galway Bay Prawn fishery may be experiencing high exposure to this form of pollution, with potential detrimental repercussions for this species, including reduced fitness and potential reproductive failure.

“However, more research is needed to understand the mechanisms influencing interactions of microplastics with individual species and ecosystems.”

The team’s research was recently published in the journal Scientific Reports.

Colm Gorey was a senior journalist with Silicon Republic