The lower Calcasieu estuary, located in southwest Louisiana, has received industrial, municipal, and agricultural discharge for the last several decades, resulting in the contamination of distinct regions of the system. This paper coordinates existing environmental data from the analyses of surface waters, sediments, and tissues of higher trophic level aquatic organisms collected by several state and federal agencies, attempting to detect spacial trends in contaminant distribution. Selected industrial facilities were examined with respect to process, effluent parameters, and wastewater treatment equipment. Surface water quality in areas has been impacted by the presence of volatile organic compounds (VOCs), and sediment contaminants detected include chlorinated benzenes, polynuclear aromatic hydrocarbons, and phthalates. State analyses of both edible portions and whole body samples of seventeen aquatic species show a very wide spacial distribution of individuals carrying elevated body burdens of hexachlorobutadiene (HCBD) and hexachlorobenzene (HCB), two of the more prevalent chlorinated hydrocarbons found in the system. While found in animals from throughout the system, HCB and HCBD were detected in only a very limited spacial range in sediments and surface waters of the system. In an attempt to understand potential mechanisms of uptake in various species, middle trophic level organisms were collected and analyzed for whole body burden concentrations of HCB and HCBD. All organisms captured in the area of localized sediment contamination showed a detectable level of these compounds, with concentrations decreasing with distance from the source. Dialysis tubing filled with iso-octane was employed as a biological surrogate to determine relative bioavailability of water-solubilized HCB and HCBD from various regions in the system. Detectable levels of both compounds were found in areas downstream, upstream, and lateral to the area of known sediment contamination. No correlation between exposure time and uptake were found, indicating that system-specific conditions (either meteorological or man-made) were affecting the relative availability of HCB and HCBD at any given time period. No correlation was found to exist between body burden concentrations of middle trophic level organisms and surrogate concentrations