Fish of the North Sea

5.5% of all investigated fishes had ingested plastic.

Significant higher ingestion frequency in pelagic feeders

Identification of the polymer type of all plastic particles

Essential controls to quantify contamination

Plastic ingestion by marine biota has been reported for a variety of different taxa. In this study, we investigated 290 gastrointestinal tracts of demersal (cod, dab and flounder) and pelagic fish species (herring and mackerel) from the North and Baltic Sea for the occurrence of plastic ingestion. In 5.5% of all investigated fishes, plastic particles were detected, with 74% of all particles being in the microplastic (< 5 mm) size range. The polymer types of all found particles were analysed by means of Fourier transform infrared (FT-IR) spectroscopy. Almost 40% of the particles consisted of polyethylene (PE). In 3.4% of the demersal and 10.7% of the pelagic individuals, plastic ingestion was recorded, showing a significantly higher ingestion frequency in the pelagic feeders. The condition factor was calculated to test differences in the fitness status between individuals with and without ingested plastic, but no direct effect was detected.

Keywords

• Marine debris;
• Plastic;
• Fish;
• Ingestion;
• North Sea;
• Baltic Sea