Published By US Fish and Wildlife Service, Department of the Interior
Issued over 9 years ago
Summary
Description
From March 9 to May 31, 1991, largemouth bass Micropterus salmoides, bowfin Amia calva, Florida gar Lepisosteus platyrhincus, brown bullhead Ictalurus nebulosus, spotted seatrout Cynoscion nebulosus, gafftopsail catfish Bagre marinus, and hardhead catfish Arius felis were collected from selected locations at St. Marks National Wildlife Refuge, Wakulla County, Florida for analysis of mercury concentrations in muscle tissue fillets. Mercury in largemouth bass n36 ranged from 0.10 to 1.28 mgkg ppm, wet weight ww. Twelve of the bass had levels that exceeded the Florida limitedconsumption concentration of 0.5 ppm ww. None of the bass exceeded the Florida noconsumption advisory of 1.5 ppm, ww. Two bowfin had mercury concentrations of 1.28 and 1.29 ppm, ww. Florida gar n 11 had mercury concentrations from 0.05 to 0.14 ppm, ww. Two brown bullhead each had 0.2 ppm mercury, ww. Mercury in spotted seatrout n 26 ranged from 0.09 to 0.60 ppm, ww. Three seatrout had mercury concentrations exceeding the limitedconsumption concentration. Gafftopsail catfish n 7 had mercury concentrations ranging from 0.33 to 0.93 ppm, ww, with four exceeding the limitedconsumption level. Hardhead catfish n 26 had mercury concentrations ranging from 0.08 to 0.75 ppm, ww. Four catfish 15 had mercury that exceeded the lowerconsumption level. All locations sampled appeared to provide environments conducive to accumulation of mercury by all species sampled. Significant differences p0.01 exist between means for bass collected at Lake Renfroe, St. Marks River and Wakallua River. Bioaccumulation rates in these oligotrophic systems may be related to differences in characteristics that affect uptake, such as low pH, low alkalinity and minimal organic concentrations. Because of the mercury found in fish during this study, it appears that several fish and wildlife trust species may be at risk when utilizing the habitat areas sampled. Additional environmental contaminant studies to determine the scope, magnitude and effects of mercury contamination are recommended.