It isn t possible to tell without conducting scientific analyses of the water, fish or sediments. Nothing in a lake s outward appearance is likely to indicate whether the lake or its fish are contaminated, or the extent to which they might be contaminated. Certain characteristics of lakes, such as the run-off area, acidity or alklalinity, adjacent wetlands, and biological activity in the lake all affect the level of methylmercury contamination in the lakes fish. The Minnesota Department of Health believes that fish consumption guidelines should take into consideration the data available on fish contamination, since the fish from two lakes very near each other may have very different levels of methylmercury contamination. In addition, people who eat sport-caught fish only while on vacation or during a particular season don t need to follow the same consumption guidelines as those who eat such fish frequently all year.
Fish are low in fat and a good source of protein and other nutrients.
According to the U.S. Environmental Protection Agency s recent report to Congress on mercury, most people in the United States can eat fish without worrying about mercury contamination. Ocean fish can be contaminated with mercury as well as freshwater fish, although levels tend to be lower. Household items containing mercury should be taken to your county s household hazardous waste disposal site. It is unlawful to place them in ordinary household garbage. Call your county s solid waste officer for the location and hours of the site nearest you.