MADISON – Wisconsin's updated fish consumption advisory booklet, "Choose Wisely, A Health Guide for Eating Fish in Wisconsin," arrives as studies show mixed trends in contaminant levels in sport-caught fish and the people who eat them.
- A Department of Natural Resources study analyzing statewide data from 1982 to 2005 found that mercury levels in walleye decreased 0.5 percent per year in northern lakes but increased 0.8 percent in southern lakes, and remained constant in middle latitudes of the state, according to Candy Schrank, a DNR toxicologist. The study found mercury generally increased with fish length but that relationship varies among lakes and other variables such as season, gender, lake area, and alkalinity are also important. The study will be published in the journal Ecotoxicology. A similar study by the Great Lakes Indian Fish and Wildlife Commission also found that walleye mercury decreased in northern lakes . This study was recently published in Environmental Science and Technology.
- A Wisconsin Department of Health and Family Services survey found that PCB levels in the blood of Great Lakes charter boat captains and anglers decreased by 30 percent between 1994 and 2003. This decline reflects a gradual decline of PCB levels in the environment and in local sportfish. PCB production ended in the United States in 1977. However, these chemicals are still found in older appliances and electrical equipment.
"While these results show that exposure to some contaminants may be less in some parts of the state compared to the 1980s, further reductions will likely depend on mercury emission controls and PCB remediation efforts," Schrank says.
SOURCE - Wisconsin Department of Natural Resources
