Grantee Research Project Results

An Integrated Assessment of Reproductive and Development Risks to Estuarine Communities Exposed to Hazardous Chemicals by Trophic Transfer

EPA Grant Number: R826399E03
Title: An Integrated Assessment of Reproductive and Development Risks to Estuarine Communities Exposed to Hazardous Chemicals by Trophic Transfer
Investigators: Burnett, Karen , Melo, A. C. , Strozier, E. D. , DeLorenzo, Marie E. , Fulton, Michael H. , Scott, Geoffrey I. , Karnaky, Karl J. , Christl, Thomas J. , Pennington, Paul L. , Ramsdell, John S. , Bearden, Daniel W , Harvey, B.
Institution: Medical University of South Carolina , National Oceanic and Atmospheric Administration , Colorado School of Mines
EPA Project Officer: Chung, Serena
Project Period: March 1, 1998 through August 31, 2000
RFA: EPSCoR (Experimental Program to Stimulate Competitive Research) (1997) RFA Text |  Recipients Lists
Research Category: EPSCoR (The Experimental Program to Stimulate Competitive Research)

Objective:

1. The overall goal of this research was to develop a broadly useful risk assessment model for environmental contaminants in estuarine communities that considers trophic transfer, metabolic fate, and varying life stage sensitivities.
2. The immediate objective of this research was to facilitate the application of a discrete set of molecular and cellular techniques, which may prove to be useful in linking the trophic transfer of an environmental toxicant to its multitrophic-level effects, including bioavailability, exposure and reproductive/developmental risk. This project provides students trained in molecular and cellular techniques with an opportunity to test these promising new assays in a dynamic field simulation, or mesocosm.
3. The model contaminant in the current project was the organochlorine pesticide, endosulfan, because of its high usage on vegetable crops in the southeast, its moderately high octanol-water partition coefficient (K_ow; 3.50–4.57), its high acute toxicity potential (96-hour LC₅₀ values of < 1 μL) for many shellfish and juvenile fish species, the very low marine quality criterion (0.0087 μg/L), and its known endocrine disrupting capability when compared to estrogen and DES.
4. Specific tasks to be accomplished under this project were to:
1. Establish functional warm water estuarine simulations
2. Determine partitioning of endosulfan from water into sediments and biota
3. Establish acute toxicity of endosulfan to bivalves, crustaceans, and teleosts within the mesocosm.
4. In a chronic exposure simulation, quantify trophic transfer and bioavailability of endosulfan at the level of primary and secondary consumers, as indicated by measurements of:
1. Exposure (direct measurement of endosulfan isomers and metabolites)
2. Metabolic fate (induction of xenobiotic transport by MXRs or p-glycoprotein PGp and the cytochrome p450-Ah receptor system)
3. Effects (estrogenic activity brain aromatase, immunocompetence) and endosulfan offloading to eggs.
5. Measure the developmental potential through hatch and swim-up of embryos exposed to endosulfan by microinjection to achieve concentrations observed in eggs.
5. Approach: The study proceeded in five discrete phases.
1. Simulation set up (Year 1). A simulation of an estuarine community was established and dosed with endosulfan.
2. Range finding trials, including acute dosing, to establish appropriate dosing ranges for chronic dosing experiments in the simulation units (Year 1).
3. Develop and test biomarker assays to be used in the simulation unit (Year 1). Laboratory dosing experiments were conducted to optimize the methods of tissue collection, preservation, and assays in major groups of organisms.
4. Model trophic transfer, fate and effects in chronic dosing experiments in the estuarine stimulation units (Year 2).
5. Measure the developmental potential through hatch and swim-up of embryos exposed to endosulfan by microinjection to achieve concentrations observed in eggs from chronic mesocosm studies (Year 1–2).

Supplemental Keywords:

mesocosm, endosulfan, estuarine simulation unit, biomarkers, P-glycoprotein, Comet Assay, trophic transfer, phagocytosis, bactericidal assay, brain aromatase, fish, shrimp, oysters, microinjection, Medaka, Fundulus heteroclitus, Crassostrea virginica, Palaeomonetes pugio,

Progress and Final Reports:

1998

1999

Final