Ingestion of Microplastics by Zooplankton in the Northeast Pacific Ocean
- 7.1k Downloads
Microplastics are increasingly recognized as being widespread in the world’s oceans, but relatively little is known about ingestion by marine biota. In light of the potential for microplastic fibers and fragments to be taken up by small marine organisms, we examined plastic ingestion by two foundation species near the base of North Pacific marine food webs, the calanoid copepod Neocalanus cristatus and the euphausiid Euphausia pacifia. We developed an acid digestion method to assess plastic ingestion by individual zooplankton and detected microplastics in both species. Encounter rates resulting from ingestion were 1 particle/every 34 copepods and 1/every 17 euphausiids (euphausiids > copepods; p = 0.01). Consistent with differences in the size selection of food between these two zooplankton species, the ingested particle size was greater in euphausiids (816 ± 108 μm) than in copepods (556 ± 149 μm) (p = 0.014). The contribution of ingested microplastic fibres to total plastic decreased with distance from shore in euphausiids (r 2 = 70, p = 0.003), corresponding to patterns in our previous observations of microplastics in seawater samples from the same locations. This first evidence of microplastic ingestion by marine zooplankton indicate that species at lower trophic levels of the marine food web are mistaking plastic for food, which raises fundamental questions about potential risks to higher trophic level species. One concern is risk to salmon: We estimate that consumption of microplastic-containing zooplankton will lead to the ingestion of 2–7 microplastic particles/day by individual juvenile salmon in coastal British Columbia, and ≤91 microplastic particles/day in returning adults.
KeywordsZooplankton Species Zooplankton Sample Juvenile Salmon Humpback Whale Plastic Particle
We thank the crew of the CCGS John. P. Tully for their generous assistance while collecting samples. Ian Perry provided thoughtful comments on the manuscript. We thank Chrys Neville and Marc Trudel for valuable feedback.
- Brodeur RD (1990) A synthesis of the food habits and feeding ecology of salmonids in marine waters of the North Pacific. FRI-UW-9016. Fisheries Research Institute, University of Washington, Seattle, WAGoogle Scholar
- Cole M, Lindeque P, Fileman E, Halsband C, Goodhead R, Moger J et al (2013) Microplastic ingestion by zooplankton. Environ Sci Technol 47:6646–6655Google Scholar
- Cole M, Webb H, Lindeque PK, Fileman ES, Halsband C, Galloway TS (2014) Isolation of microplastics in biota-rich seawater samples and marine organisms. Sci Rep 4:4528Google Scholar
- Foekema EM, De Gruijter C, Mergia MT, van Franeker JA, Murk AJ, Koelmans AA (2013) Plastic in north sea fish. Environ Sci Technol 47:8818–8824Google Scholar
- Fossi MC, Coppola D, Baini M, Giannetti M, Guerranti C, Marsili L et al (2014) Large filter feeding marine organisms as indicators of microplastic in the pelagic environment: the case studies of the Mediterranean basking shark (Cetorhinus maximus) and fin whale (Balaenoptera physalus). Mar Environ Res 100:17–24CrossRefGoogle Scholar
- Ishida Y, Ito S, Ueno Y, Sakai J (1998) Seasonal growth pattern of Pacific salmon (Oncrohynchus spp) in offshore waters of the North Pacific Ocean. North Pac Anadromous Fish Comm Bull 1:66–80Google Scholar
- Nakagawa Y, Endo Y, Taki K (2001) Diet of Euphausia pacifica Hansen in Sanriku waters off northeastern Japan. Plankton Biol Ecol 48:68–77Google Scholar