Estuarine marshes have been shown to trap microplastic particles. The ingestion of microplastics by estuarine fishes varies greatly depending on the feeding strategies of different fish species.  We analyzed trophic pathways leading to microplastic ingestion by comparing microplastic loads in intestinal tracts from estuarine fishes in South Carolina (USA).  Fibers were the most common type of plastic in all species, but plastic fragments, foam and tire wear particles were also abundant. Benthic feeding fishes with distributions restricted to vegetated marsh habitats where microplastics are trapped had higher concentrations of microplastics than those inhabiting nearby sandy environments with higher water flow. Planktivorous fishes had the highest loads of microplastics of all fishes, including predatory and detritivore species. Planktivorous juvenile Atlantic Menhaden selectively feed on marine snow particulate aggregates showed the highest concentrations of ingested microplastics. Larger predatory shark species specie that mainly feed on Atlantic Menhaden showed higher microplastic concentrations than those targeting other prey species, indicating the potential key role that marine snow particles and Menhaden play in the trophic distribution of microplastics through estuarine food webs in the western Atlantic. In-depth spatial differences between fish species from our ongoing sampling efforts will be discussed to further characterize trophic pathways of microplastic and tire wear particle ingestion in estuarine ecosystems.

Primary Presenter: Gorka Sancho, College of Charleston (sanchog@cofc.edu)

Authors:

Brittney Parker, Lynker  (Brittney.parker@noaa.gov)

Morgan Lattomus, South Carolina Department of Natural Resources  (lattomusm@dnr.sc.gov)

Brianna Ingram, University of North Carolina Chapel Hill  (ingrambc@email.unc.edu)

Ashley Galloway, South Carolina Department of Natural Resources  (gallowaya@dnr.sc.gov)

Bryan Frazier, South Carolina Department of Natural Resources  (frazierb@dnr.sc.gov)

Joseph Ballenger, South Carolina Department of Natural Resources   (ballengerj@dnr.sc.gov)

Barbara Beckingham, College of Charleston  (beckinghamba@cofc.edu)