Microplastics in juvenile Chinook salmon and their nearshore environments on the east coast of Vancouver Island.

Environ Pollut. 2018 Sep 28;244:135-142. doi: 10.1016/j.envpol.2018.09.137. [Epub ahead of print] Collicutt B1, Juanes F2, Dudas SE3. Author information 1 Department of Biology, University of Victoria, 3800 Finnerty Rd, Victoria, British Columbia, V8P 5C2, Canada; Department of Biology, Vancouver Island University, 900 Fifth St, Nanaimo, British Columbia, V9R 5S5, Canada; Hakai Institute, 1713 Hyacinthe Bay Rd, Quadra Island, British Columbia, V0P 1H0, Canada. Electronic address: Brenna.Collicutt@hakai.org. 2 Department of Biology, University of Victoria, 3800 Finnerty Rd, Victoria, British Columbia, V8P 5C2, Canada. 3 Department of Biology, University of Victoria, 3800 Finnerty Rd, Victoria, British Columbia, V8P 5C2, Canada; Department of Biology, Vancouver Island University, 900 Fifth St, Nanaimo, British Columbia, V9R 5S5, Canada; Hakai Institute, 1713 Hyacinthe Bay Rd, Quadra Island, British Columbia, V0P 1H0, Canada. Abstract Microplastics are a significant issue in the world's oceans. These small plastic particles (<5 mm in size) are becoming globally ubiquitous in the marine environment and are ingested by various fish species. Here we investigate the incidence of microplastics in juvenile Chinook salmon and their nearshore marine environments on the east coast of Vancouver Island, British Columbia. We completed a series of beach seines, plankton tows and sediment cores in nearshore areas of importance to juvenile salmon. Microplastics were extracted from fish, water and sediment samples and concentrations were quantified. Microplastics analysis, consisting predominantly of fibrous plastics, showed juvenile Chinook salmon contained 1.2 ± 1.4 (SD) microplastics per individual while water and sediment samples had 659.9 ± 520.9 microplastics m-3 and 60.2 ± 63.4 microplastics kg-1 dry weight, respectively. We found no differences in microplastic concentrations in juvenile Chinook and water samples among sites but observed significantly higher concentrations in sediment at the Deep Bay site compared to Nanaimo and Cowichan Bay sites. Chinook microplastic concentrations were relatively low compared to literature values and, given the size and type of microplastics we observed, are unlikely to represent an immediate threat to fish in this area. However, microplastics less than 100 μm in size were not included in the study and may represent a greater threat due to their ability to translocate through tissues. KEYWORDS: Ingestion; Microplastics; Oncorhynchus tshawytscha; Vancouver Island