The continental shelf is the extension of a state’s territorial waters. It is an area of seabed where the sea is relatively shallow compared with the open ocean.
Researchers from NUI Galway found that microplastic contamination was present along the western Irish continental shelf, regardless of proximity to densely populated areas.
They also found a “ statistically significant” decrease in microplastic abundance the deeper they went into sediment near Galway Bay.
Their discovery supports the assumption that microplastic deposition is increasing over time in the area.
The study, published this week in the international journal Scientific Reports is the first assessment of microplastic pollution in marine sediments taken from the Irish continental shelf.
Sea pollution caused by plastic is a global issue. Microplastics are plastics smaller than 0.5mm and are widely dispersed throughout the marine environment.
It is now widely recognised that an understanding of the distribution and accumulation of this form of pollution is crucial for gauging environmental risk.
Senior study author Audrey Morley said some forms of shellfish might be exposed to the “pervasive presence” of microplastics on the Irish sea floor.
“However, more research is needed to understand the mechanisms influencing interactions of microplastics with individual species and ecosystems,” said Dr Morley, who is a lecturer in physical geography at NUI Galway.
All of the recovered microplastics appeared to be the remnants of larger items.
Fibres were the principle form of microplastic pollution (85%), followed by broken fragments (15%) and are thought to originated from a variety of sources.
The research was funded by the Geological Survey of Ireland and the Marine Institute of Ireland.