Low levels of microplastics recorded from the common periwinkle, Littorina littorea on the west coast of Ireland

Microplastics (MPs) are an environmental pollutant of increasing concern. However, little research has assessed MP levels in intertidal gastropods. The authors explored MP abundance in the gastropod Littorina littorea from four sites within Galway Bay, West Ireland. To do this, 50 L. littorea were collected from four rocky shores of varying wave exposure, with two sites located in the north of the bay and two in the south. An additional 50 individuals were taken from a commercial exporter, to determine MP levels in L. littorea intended for human consumption. MPs were recovered from 60.4% of the individuals and the average MP level was 2.14 MPs/gram of wet soft body mass. MP levels differed significantly between sites, with the two northern sites having the highest levels. Oceanographic conditions within Galway Bay are likely responsible for the observed variation in MP abundance, with the North Sound of the bay potentially facilitating deposition.