Research Product

The genotoxic potential of environmental media collected from coastal areas impacted by anthropogenic contaminants has not been reported frequently in the scientific literature, particularly in the Gulf of Mexico region. This report summarizes the microbial mutagenicity of 31 pore waters obtained from surficial sediments impacted by non-point source runoff and compares the results to more traditional chemical and biological measures of sediment quality. Pore waters were extracted by centrifugation from sediments collected adjacent to a Florida coastal golf complex and from those in a nearby urbanized bayou-estuary. Genotoxicity was determined using a commercially-available short-term screening assay. Sediments and associated pore waters were analyzed also for acute toxicity to either Hyallela azteca, Palaemonetes pugio or Mysidopsis bahia and benthic macroinvertebrate diversity. Genotoxic activity (direct and enzyme-activated) was detected in 4 of 17 pore waters (golf complex) and 10 of 14 pore waters (urbanized bayou). The lowest detectable effect pore water concentrations were between 1.8 and 44.4% (direct) and 2.6 and 25% (enzyme-activated). The results of the genotoxic assay paralleled those based on exceedances of proposed sediment quality guidelines and pore toxicity to P. pugio in 81% and 58% of the comparisons, respectively. Shannon-Wiener diversity index values were significantly less in sediments containing genotoxic pore waters.