Plastic in North Sea Fish

TLDR

The study quantified ingested plastic in 1,203 North Sea fish from seven species and examined whether plastic ingestion affected fish condition. Samples were sieved at 0.2 mm, retaining particles >0.2 mm (median 0.8 mm) and excluding fibers identified as contamination artifacts. Plastic was found in 2.6% of fish, with higher prevalence in the southern North Sea (5.4%) and in English‑Channel cod (>33%); most fish contained a single particle (0.04–4.8 mm), and plastic presence did not correlate with fish condition.

Abstract

To quantify the occurrence of ingested plastic in fish species caught at different geographical positions in the North Sea, and to test whether the fish condition is affected by ingestion of plastics, 1203 individual fish of seven common North Sea species were investigated: herring, gray gurnard, whiting, horse mackerel, haddock, atlantic mackerel, and cod. Plastic particles were found in 2.6% of the examined fish and in five of the seven species. No plastics were found in gray gurnard and mackerel. In most cases, only one particle was found per fish, ranging in size from 0.04 to 4.8 mm. Only particles larger than 0.2 mm, being the diameter of the sieve used, were considered for the data analyses, resulting in a median particle size of 0.8 mm. The frequency of fish with plastic was significantly higher (5.4%) in the southern North Sea, than in the northern North Sea above 55°N (1.2%). The highest frequency (>33%) was found in cod from the English Channel. In addition, small fibers were initially detected in most of the samples, but their abundance sharply decreased when working under special clean air conditions. Therefore, these fibers were considered to be artifacts related to air born contamination and were excluded from the analyses. No relationship was found between the condition factor (size–weight relationship) of the fish and the presence of ingested plastic particles.