You are here:
AN EVALUATION OF THE USE OF COLONIZED PERIPHYTON AS AN INDICATOR OF WASTEWATER IMPACT IN NEAR-COASTAL AREAS OF THE GULF OF MEXICO.
Citation:
Lewis, M A., D. A. Weber, AND J C. Moore. AN EVALUATION OF THE USE OF COLONIZED PERIPHYTON AS AN INDICATOR OF WASTEWATER IMPACT IN NEAR-COASTAL AREAS OF THE GULF OF MEXICO. ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 43(1):11-18, (2002).
Description:
The phytoassessment of wastewater-impacted coastal areas is not common in the Gulf of Mexico region. The objective of this research was to provide some initial information on this issue for eight industrial, municipal, and forest product wastewaters using periphyton as an indicator of impact. Effects on biomass and pigment content were determined for periphyton colonized in-situ for 21 days at 35 sites located above and below wastewater outfalls. Chemical analysis of receiving waters was also conducted at the time of the colonizations. Most physico-chemical parameters were unaffected in the receiving waters and most trace metals, pesticides, PAHs and PCBs were below detection. In contrast, nutrient concentrations increased considerably below the eight outfalls and were greater compared to concentrations reported for other estuaries. The impacts on periphyton were specific to the wastewater, colonization site, response parameter and colonization frequency. The differences in response suggest that data extrapolations among different types of wastewaters should be made with caution. Inhibition was uncommon but significant increases in biomass and pigment content occurred at least at one location below all outfalls and at a total of 17 of 28 non-control colonization sites (P < 0.05). Ash free dry weight increased, on average, by 129.9 (? 1 standard deviation = 121.2)% and chlorophyll a, increased by 271 (? 557)%, in the wastewater-impacted areas. The phytostimulation was limited usually to near-field areas and paralleled the data trend observed in laboratory whole effluent phytotoxicity tests conducted with cultured algae. Periphyton colonization was judged useful as an in-situ indicator of wastewater impact but the experimental design needs careful consideration to ensure relevancy of the results in the often dynamic Gulf of Mexico near-coastal region.