Microplastics in spawning Chinook and Coho salmon from Lake Ontario

Session: Microplastics in the Environment: Source, Fate, Impact, Detection, and Mitigation (1)

C. Eric Hellquist, State University of New York Oswego, [email protected]
Linden Merrill, State University of New York Oswego, [email protected]

Abstract

Microplastics are being found throughout food webs in the Laurentian Great Lakes.  In Lake Ontario, we have found ubiquitous microplastics in four species of prey fish.  Here we examine two species of top predator in Lake Ontario food webs. We collected stomachs of Chinook (Oncorhynchus tshawytscha) and Coho (Oncorhynchus kisutch) salmon at the Salmon River Fish Hatchery (Altmar, NY) in October 2017 and 2018.  Stomachs were dissected and dissolved to isolate microplastic particulates.  Like our previous work with prey fish, microlitter frequency was high in Chinook (89%) and Coho (100%).  Our sampling to date indicates a difference in total particulates between species (p=0.003).  Chinook (n=28) have a mean of 2 pieces of microlitter per individual and Coho (n=16) have 3.6 pieces per individual.  Both species had approximately 2 filaments per individual (range 0-5). Coho had 1.5 fragments per individual (range 0-5) compared to 0.07 fragments per individual (range 0-1) for Chinook.  These results will be expanded by our ongoing sample processing from 2018.  Based on comparisons to our data from Lake Ontario Alewife, Round Goby, Deepwater Sculpin, and Slimy Sculpin, it appears that Chinook and Coho are retaining less microlitter in their digestive tracts than prey species.