Marine neustonic microplastics around the southeastern coast of Korea

Abstract

We investigated floating debris around the mouth of the Nakdong River in the Southeastern Sea of Korea using a Manta trawl (330-μm mesh) and hand-net (50 μm) before (May) and after (July) the rainy season in 2012. Microplastic (<2 mm) was present at all of the stations, whereas Styrofoam (2-5 mm) peaked only at a few stations far from the Nakdong River mouth in July. The dominant types were fibers (polyester), hard plastic (polyethylene), paint particles (alkyd), and Styrofoam (expanded polystyrene). The average abundances of fibers and hard plastic (<2 mm) in the trawl were significantly higher in July than in May (p<0.005, p<0.05, respectively), while two orders of magnitude more microplastics (<2 mm) were collected with the hand-net than with the trawl. Fibers and hard plastic by trawl were significantly compared temporally, and the hand-net proved the missed microplastics (50-330 μm) when trawl used.

Keywords: A Manta trawl net; A hand-net; Floating debris; Microplastics; Nakdong River mouth; Rainy season.