The distribution and abundance of microplastic pollution in Northern Ireland’s freshwater ecosystems and their effect on macroinvertebrates

Concentrations in water, sediment, and macroinvertebrate tissues were below harmful thresholds for all macroinvertebrate taxa found in the freshwater surveys. Exposure tests on amphipod species, Gammarus duebeni celticus and Gammarus pulex, revealed that microplastics did not inhibit their leaf shredding or predation roles at prevalent concentrations. Furthermore, these taxa show resilience to microplastics under deoxygenation, an aspect of anthropogenic pollution and climate change expected to rise and co-occur with the projected increase in microplastic pollution.

However, species-specific differences in microplastic effect on Gammarus leaf shredding behaviour were observed at very high microplastic concentrations, contributing to the growing body of evidence that species-specific assessments for microplastic exposure are needed for accurate prediction of the impacts of this contaminant.<br><br>Conclusively, the current microplastic risk to NI's freshwater macroinvertebrates and their ecosystem functions is minimal.

This offers NI authorities a unique opportunity to implement effective mitigate strategies, using this study's data, to prevent a substantial increase in microplastic pollution and maintain the health of our freshwater systems.<br><br><br>