Plastics in estuarine fish and sediments at the mouth of an urban watershed

Project completed, manuscript in prep.

Project team: T.S. Talley, N. Venuti- CASG; R. Whelan- U. of San Diego.

The extent to which small plastics and potentially associated compounds are entering coastal foodwebs, especially in estuarine systems, is only beginning to be realized. Using estuarine fish and sediment collected during June 2015 from urbanized Chollas Creek, in San Diego, California, we tested the hypotheses that small plastic composition in sediments would be reflected in fish guts (non-selective consumption), and that semi-volatile organic compounds (SVOCs) would be present in all fish. Sediments contained about 10,000 small plastic pieces per m2, consisting mostly (90%) of fibers, and hard and soft pieces. Nearly 25% of fish contained small plastics, but prevalence varied with size and between species. Of the 39 types of small plastics found in sediment, fish preferred 10 types (distinct colors and forms). Several SVOCs, both water soluble and sediment-associated compounds, were found in the two species of fish tested. We conclude that a species’ natural history may influence contamination levels with consequences, and lessons, for all consumers.