Validation of Sediment Quality Criteria in Southeastern EstuariesEPA Grant Number: R826201
Title: Validation of Sediment Quality Criteria in Southeastern Estuaries
Investigators: Ringwood, Amy Huffman
Institution: South Carolina Department of Natural Resources , Marine Resources Research Institute
EPA Project Officer: Carleton, James N
Project Period: December 1, 1997 through November 30, 2000 (Extended to November 30, 2001)
Project Amount: $449,794
RFA: Contaminated Sediments (1997) RFA Text | Recipients Lists
Research Category: Ecological Indicators/Assessment/Restoration , Hazardous Waste/Remediation , Land and Waste Management
Validation of models for establishing sediment quality criteria (SQC) requires simultaneous assessments of physicochemical parameters and biological effects. An integrated approach is proposed to evaluate the value of various models for estimating potential biological effects due to metal contamination in southeastern estuaries. The specific purpose of these studies is to evaluate the relationships between sediment/porewater parameters and biological responses (toxicity and bioaccumulation with infaunal and epifaunal bivalves, benthic community integrity) for metal contaminated sediments. The major objectives will be to: (1) Evaluate the importance of sediment and porewater parameters (AVS, TOC, % silt-clays, pH, SEM, metal concentrations in interstitial water, ammonia) to toxicity and bioavailability of a suite of priority metals (Cd, Cu, Ni, Pb, Zn) in a field setting. (2) Evaluate seasonal changes in sediment chemistry and effects on toxicity and bioavailability. (3) Conduct in situ seed clam assays as well as laboratory assays to evaluate the degree to which laboratory toxicity assays reflect in situ toxicity. (4) Evaluate the value of current bioavailability models to predict chronic as well as acute toxicity.
Studies will be conducted at polluted and unpolluted sites during the winter and summer which will involve sediment and porewater chemistry, chronic toxicity assays (laboratory and in situ assays using seed clams, Mercenaria mercenaria), bioaccumulation studies with two bivalve species (an infaunal clam species, M. mercenaria, and an epifaunal oyster species, Crassostrea virginica), and benthic community studies.
These studies will provide comprehensive data regarding sediment and porewater characteristics, toxicity, and bioaccumulation. These studies will enable evaluation of the utility of various bioavailability and toxicity models (equilibrium partitioning, interstitial water toxicity units, apparent effects threshold, and sediment triad approach) for development of SQC. Seasonal differences will be identified. The seed clam growth assay provides a valuable means of evaluating the potential for chronic as well as acute toxicity, and concurrent laboratory and in situ assays will allow us to evaluate their efficacy as indicators of real-world toxicity. Sediment quality criteria should be developed that will minimize the potential for degradation of estuarine resources as well as minimize human health risks.