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Bioeffects Assessment Study: St. Lucie Estuary

Bioeffects Assessment Study: St. Lucie Estuary

Abstract

The Bioeffects Assessment Project of the NS&T Program conducts intensive regional surveys to describe the incidence, severity, and the spatial extent of adverse biological effects associated with chemical contamination. By combining and synthesizing data of chemical contaminants levels in sediment and biota, results of multiple toxicity tests, analysis of biomarker responses, and changes in benthic biological community structure, Bioeffects Assessment studies provide a holistic understanding of regional environmental quality and the spatial extent of contamination-related adverse biological effects.  The St. Lucie Bioeffects Study is the 26th such study conducted by NS&T.

The St. Lucie Estuary and adjacent watershed have been highly altered in recent years from increased human population growth, intense agriculture and related activities, and periodic release of large amounts of freshwater from Lake Okeechobee.  Heavy freshwater discharge following the 1998 El Niño event was associated with observations of unusually large incidences of fish with lesions and other deformities, further exacerbating concerns about the ecological conditions of the estuary and status of its renewable resources. Since the St. Lucie Estuary is hydrologically connected to the Everglades, its study is also part of the larger ecosystem restoration and freshwater management efforts in South Florida.

Objectives

The purpose of this Bioeffects Assessment is to characterize St. Lucie Estuary in terms of environmental toxicity and to describe the extent and severity of habitat degradation using the sediment quality triad (SQT) approach.  The SQT evaluates three data types: sediment chemistry, sediment toxicity, and benthic community infauna abundance and diversity.  The study design is in context of the major issues of concern that have been articulated by the St. Lucie River Issue Team (SLRIT), notably the issue dealing with the impact of freshwater discharges on the environmental quality of the estuary. The study includes the following activities:

  1. Describe the levels and spatial distribution of contaminants in the St. Lucie Estuary and adjacent waters;
  2. Describe the incidence, severity and spatial extent of toxicity, including possible genotoxic effects and changes in benthic faunal community;
  3. Describe the study results in relation to known or suspected sources of contamination;
  4. Describe statistical relationships between levels of contaminants and adverse biological effects, and identify chemicals of concern in terms of regional environmental quality and adverse biological effects;
  5. Compare environmental conditions within sub-areas of St. Lucie Estuary and compare estimates of toxicity in St. Lucie Estuary with those in other estuaries based on comparable data.

Time Frame

2006.

For More Information

Project Manager:
Ed.Johnson@noaa.gov
1305 East West Highway
SSMC-IV, N/SCI-1
Silver Spring, MD 20910
301-713-3028 x149