(NaturalNews) Authorities are warning that bass at several of the most popular fishing destinations in Arizona and California have accumulated excessive mercury levels.

In California, 180 reservoirs are contaminated with high mercury levels. The State Water Resources Control Board took fish samples from more than 300 of the state's reservoirs to make that determination. The board is now urging the reservoirs' owners to post voluntary warnings about eating the fish that are at the top of the food chain, such as bass. These fish tend to accumulate the most mercury, posing a particular risk to children and pregnant women.

Even though the warnings are intended to help protect human life, those who depend on the income brought by tourists and sportsmen to the bodies of water in question are reluctant to post voluntary warnings and draw attention to the matter.