Natural history matters: Plastics in estuarine fish and sediments at the mouth of an urban watershed

Abstract

The extent to which small plastics and potentially associated compounds are entering coastal food webs, especially in estuarine systems, is only beginning to be realized. This study examined an estuarine reach at the mouth of urbanized Chollas Creek in San Diego, California to determine: 1) the extent and magnitude of microplastics pollution in estuarine sediments and fish, 2) the extent and magnitude of SVOC contamination in estuarine fish, and 3) whether fish preferentially ingested certain types of microplastics, when compared with the microplastic composition of creekbed sediments. Surface sediments (0-5 cm depth) 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 25 types of small plastics found in sediment, fish preferred about 10 types (distinct colors and forms). Several SVOCs, both water soluble and sediment-associated compounds, were found in the two species of fish tested. This study revealed that a species’ natural history may influence contamination levels, and warrants further study to better understand the pathways of plastics and associated contaminants into and throughout coastal food webs, and the potential health risks for small and/or low-trophic level organisms.

TSC Opinion

Cet article est très riche en données. Il montre la façon dont les microparticules de plastique et leurs polluants associés entrent dans les réseaux trophiques (chaines alimentaires). Leurs études ont permis de mettre en évidence des particularités encore jamais décrites. Les espèces qui ont été en contact avec ces matières et polluants se sont adaptées et présentent des niveaux de contamination moins élevés. Cet aspect va compliquer la modelisation à grande échelle des impacts, en particulier dans les zones où la pollution est bien établie depuis des années.