Temporal-spatial distribution of Macroinvertebrates on marine plastic debris in the southern sea of Korea

Abstract

The recruitment of marine organisms by marine plastic debris (MPD) presumably affects the species diversity and community structure of the marine ecosystem, but relevant research is limited. This study analyzed the temporal-spatial distribution characteristics of attached macroinvertebrates on MPD. The Macroinvertebrates attached on MPD were collected once every three months from March to December 2021 in eight regions. MPD materials on aquaculture and fishing gear were most frequently detected during the study; foreign-originating MPD was present in Jeju Island and Shinan. In total, two phyla, 14 orders, 19 families, and 41 species of attached macroinvertebrates were detected during the investigation. Attached macroinvertebrates increased more on MPD from the ocean than on MPD from land, and the number of species that appeared was high on MPDs with soft surfaces such as EPS (Expanded Polystyrene) or rough materials such as ropes. Among the surveyed areas, the number of species was high in Jeju Island and the Shinan. However, there was no difference in the number of observed species according to the collection period. On the entire MPD, the individual numbers of the alien species Mytilus galloprovincialis (blue mussel) was high. Among Chinese-originating MPD, the pelagic species, Lepas (Lepas) anatifera (gooseneck barnacle) was predominant on plastic bottles. These findings suggest that the temporal-spatial distribution of attached macroinvertebrates on MPD may be affected by the duration of exposure to the water layer and the characteristics of the MPD material. In particular, the high appearance of L. anatifera on Chinese-originating MPD suggests that MPD flowing into the ocean serves as a passageway for the inflow of alien species, indicating a need for continuous monitoring.