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COMPARATIVE ECLOGICAL CONDITION OF BAYOUS TEXAR, CHICO AND GRANDE
Citation:
Lewis, M A., J C. Moore, L R. Goodman, R S. Stanley, J M. Patrick, AND R L. Quarles. COMPARATIVE ECLOGICAL CONDITION OF BAYOUS TEXAR, CHICO AND GRANDE. Presented at Coastal Ecology Class, University of West Florida, Pensacola, FL, March 01, 2003.
Impact/Purpose:
Presentation for college class
Description:
Water and sediment quality in three urban bayous or tidal estuaries located near Pensacola, Florida, were determined at 23 sampling stations over a three year period during which hurricane and dredging activity occurred. Our primary objective was to determine the environmental condition of the bayous by comparing observed values for sediment and surface water to published guidelines and criteria developed to protect aquatic life. In addition, the temporal and spatial variation in chemical and biological quality were determined to provide information on the impact of seasonal differences and location of sampling stations on the chemical characterization of the bayous. Surface water concentrations of most contaminants such as heavy metals, organochloride pesticides, PAHs and PCBs were usually below detectable limits. The major exception of this trend was for copper, which often exceeded Florida state and national water quality criteria. Sediment contamination was site-specific and chemically diverse in the three bayous. The concentrations of 20 contaminants exceeded proposed sediment quality assessment guidelines indicating the likelihood for some level of sediment toxicity. Sediment toxicity, however, was moderate in most areas although "hot" spots were identified. Summer-early fall nutrient concentrations with one exception, were not unusual based on concentrations reported for other Florida estuaries. Periphyton biometrics varied considerably as did the composition of the benthic community. Finally, a contaminant gradient was evident in some bayous, sediment quality generally improved for those sampling stations located nearer the entrance to Pensacola Bay. Consequently, the three bayous may serve as contaminant sinks, reducing the probability of adverse biological effects occurring in Florida's fourth largest estuarine system, Pensacola Bay.