Microplastics in beluga whale (Delphinapterus leucas) prey: An exploratory assessment of trophic transfer in the Beaufort Sea

Microplastics (MPs, <5 mm in length) have been identified as emerging contaminants in marine environments, with ingestion by a variety of biota being of increasing concern. Few studies exist on MP ingestion in Arctic fish, and there are currently no such data from the Beaufort Sea. We investigated MP abundance in five ecologically valuable species from three sampling sites in the Eastern Beaufort Sea to evaluate possible trophic-level pathways of MPs from prey to beluga whales. Polymer analysis confirmed that 21% of fish gastrointestinal tracts (n = 116) contained microplastic particles. Fish that contained MPs had a mean abundance of 1.42 +/- 0.44 particles per in-dividual and an overall mean abundance of 0.37 +/- 0.16 particles. No plastic particles >5 mm were found, and 78% of the particles observed were fibers. Based on energetic needs, we estimate that individual beluga may ingest between 3800 and 145,000 microplastics annually through trophic transfer, with uncertain health implications. (c) 2021 Published by Elsevier B.V.

Automated summary

Microplastics have been identified as emerging contaminants in marine environments, with a study finding that 21% of fish gastrointestinal tracts in the Eastern Beaufort Sea contain microplastic particles, mainly fibers. It is estimated that beluga whales may ingest between 3800 and 145,000 microplastics annually through trophic transfer, with uncertain health implications needing further research.