Quantification of microplastic ingestion by the decapod crustacean Nephrops norvegicus from Irish waters

Microplastics are widespread pollutants in the marine environment, yet few studies have assessed the abundance and characteristics of microplastics in commercial species. This study evaluates the presence of ingested microplastics in the gastrointestinal tract of Nephrops norvegicus (n = 150), collected from five Irish prawn grounds. The efficiency of three digesting solutions was assessed. The most efficient digestion was the KOH (10%) solution incubated at 40 °C for a 48 h period. An average of 1.75 ± 2.01 items per individual was ingested by c. 69% of N. norvegicus examined. A total of 262 microplastic, predominantly fibres (98%), between 1 and 2 mm were recorded. Although, no spatial pattern was identified, samples from the North Irish Sea recorded highest occurrence of microplastics (~83%). A positive correlation was found between microplastic abundance and prawn carapace condition. Results indicate microplastic exposure in seafood for human consumption, in Ireland, is estimated to range from 15 to 4471 particles per year.