The Irish Sea is an important area for Norway Lobster Nephrops norvegicus fisheries, which are the most valuable fishing resource in the UK. Norway lobster are known to ingest microplastic pollution present in the sediment and have displayed reduced body mass when exposed to microplastic pollution. Here, we identified microplastic pollution in the Irish Sea fishing grounds through analysis of 24 sediment samples from four sites of differing proximity to the Western Irish Sea Gyre in both 2016 and 2019. We used µFTIR spectroscopy to identify seven polymer types, and a total of 77 microplastics consisting of fibres and fragments. The mean microplastics per gram of sediment ranged from 0.13 to 0.49 and 0 to 1.17 MP/g in 2016 and 2019, respectively. There were no differences in the microplastic counts across years, and there was no correlation of microplastic counts with proximity to the Western Irish Sea Gyre. Considering the consistently high microplastic abundance found in the Irish Sea, and the propensity of N. norvegicus to ingest and be negatively impacted by them, we suggest microplastic pollution levels in the Irish Sea may have adverse impacts on N. norvegicus and negative implications for fishery sustainability in the future.
Introduction
The production of plastic has now reached record levels, with > 350 million tons produced in 20191. This growth coincides with consumer demand in an ever-growing world population, where plastic products are utilised daily. A lack of suitable waste management has led to an estimated 10% of total plastic production entering marine environments every year2. As a result, plastic pollution is now a common feature of marine systems and has been found in remote areas such as the Polar Regions3 and the deep-sea4. To date, few studies have investigated the presence of plastic pollution in sediment from commercial fishing grounds, which is critical to understand the relative importance of microplastics as a threat for sustainable fisheries.
The formation of secondary microplastic particles (< 5 mm) through the fragmentation of larger sized plastics in marine systems, and the input of primary (i.e. manufactured) microplastics from terrestrial and aquatic systems is now a major environmental concern5,6. Owing to microplastic ubiquity in marine systems and the wide variety of feeding mechanisms in marine organisms, the ingestion of microplastics has been documented across many taxa7, with associated adverse impacts ranging from organ damage to reduced energy levels8. Negative impacts have also been found in commercially important fishery species bound for human consumption; including reduced body mass in crustaceans9, and reduced byssus thread production in bivalves….ReadMore