Laboratory evaluation of floating marine plastic debris as a potential vector for transportation of the harmful benthic dinoflagellate Fukuyoa koreansis

Abstract

Marine plastic debris (MPD) can significantly impact marine ecosystems because it can function as a dispersal vector for organisms, including toxic and alien species. We performed laboratory experiments to assess the possible function of MPD as a dispersal vector for the harmful epiphytic dinoflagellate Fukuyoa koreansis. Specifically, we monitored growth of these cells under 6 conditions: no MPD (control; with or without agitation), with polyethylene (PE) film (sheet-like MPD; with or without agitation), and with polypropylene (PP) rope (cylindrical MPD; with or without agitation). Growth without agitation was not significantly different between experimental groups (p > 0.05, χ2 = 0.228, Kruskal-Wallis test), indicating that the presence of MPDs had no significant effect on growth of F. koreansis under non-agitating conditions. After 15 days, growth without MPD was 25-fold greater without agitation than with agitation (150 ± 42 cells mL-1 vs. 6 ± 1 cells mL-1). When grown with both floating MPDs and agitation, 78 ± 1 % of the cells were attached to the MPD, which was 4-times greater than when they were grown without agitation. These results suggest that MPD or another attachment substrate is essential for the growth of F. koreansis in an unstable water mass, and that MPD may provide a habitat or shelter for F. koreansis and thereby function as a dispersal vector for this harmful epiphytic dinoflagellate.