Effects of an Adsorbed Pollutant on the Trophic Transfer of Microplastics in Estuarine Food Webs

Session: Poster session

Samantha Athey, UNC-Wilmington, [email protected]
Anthony Andrady, NCSU, [email protected]
Alison Taylor, UNC-Wilmington, [email protected]
Susanne Brander, Oregon State University, [email protected]

Abstract

Microplastics are becoming more abundant in estuarine systems. The surface of plastic attracts lipophillic pollutants, such as DDT, that can leach into the tissues of marine organisms upon ingestion. This study used larval silversides, Menidia beryllina, as predators, and tintinnid ciliates, Favella spp., as prey. LDPE microspheres (10-20µm) treated with DDT were used to determine whether the presence of plastic-associated pollutants affects the feeding behavior of larval fish and their prey. After one two-hour feeding period, trophic transfer treatment groups ingested a significantly higher number of microplastics than direct ingestion treatment groups, suggesting ingestion of contaminated prey could be an important route for microplastic exposure. Larvae also ingested significantly more prey exposed to DDT-laden plastics than prey exposed to virgin plastics. DDT seems to play a role in the prey preference of larval fish and potentially affects the predator avoidance behavior of Favella. Microplastic gut retention time of larval silversides was also investigated. The rate of excretion of microplastics integrated over the entire sampling period was 0.15 particles hour^-1. The inland silverside and Favella microzooplankton are common prey items for commercially important fish species. The transfer of contaminated plastics throughout the food web are major concerns in estuarine systems. 

1. Keyword
microplastics

2. Keyword
trophic level

3. Keyword
zooplankton

4. Additional Keyword
forage fish

5. Additional Keyword
estuaries