Fish tissue quality in near-coastal areas of the Gulf of Mexico receiving point source discharges

The objective of this study was to determine inorganic and organic contaminant concentrations in edible tissue of fish collected from eight coastal areas receiving wastewater discharges and from two reference locations. Trace metal residues were statistically similar regardless of the collection site. Zinc Ž100% detection in all samples., total mercury Ž100%., total arsenic Ž92%., copper Ž92%., and selenium Ž88%. were the more commonly detected trace metals. Mercury concentrations exceeded the Florida health-based standard of 0.5 g g for limited fish consumption in 30% of the total samples and averaged 0.40 Ž 1 S.D. 0.22, range 0.08 to 0.85. g g wet weight. The average total PAH concentrations were 1.79 Ž 1.60. ng g Žreference areas. and 2.17 Ž 3.29. ng g Žwastewater-impacted areas.. Pyrene was detected most frequently Ž63% of the total samples. and averaged 0.74 Ž 0.35. ng g wet wt. The average total PCB concentrations were 4.8 Ž 7.1. ng g Žreference areas. and 31.6 Ž 31.3. ng g Žwastewater-impacted areas. Concentrations of dieldrin and cis-chlordane were approximately eight times greater, respectively, in fish collected from wastewater receiving waters, whereas total DDT and total pesticide concentrations were not elevated in the same areas. Concentrations of total PCBs and all chlorinated pesticides were below US health-based standards. The lack of a published reference data base for fish tissue quality in near-coastal areas of the Gulf of Mexico restricts an assessment of the environmental significance of results from this and similar studies investigating the fate of point source contaminants.