Pond Boss Forums INTRO Questions & Observations Mercury levels in private ponds

I grew up in Florida all my life and from time to time, we have fish consumption advisory for mercury. What causes mercury in water sources? Are some states more susceptible to mercury poisoning than others? Do cattle produce any harmful pollutants in ponds? Also, how can maintain a healthy pond for harvesting fish?

I can't speak about FL but here in MN we get mercury in our water from paper factory fallout mostly from Canada (mercury goes up the stacks and comes down in the rain). Some how they use mercury in making paper. We also have naturally occuring mercury that leaches out of rocks.

I think it may occur in some coal deposits, and hence the exhaust from some coal-burning power plants, as well.

In CA its from the gold rush, both from the mining of Hg (mercury) near the coast, and from recent sedimentation of Hg used in the mountains during the processing of gold....it made its way across the entire width of CA and is present in the S.F. Bay, estuaries, and near shore Pacific ocean. Advisories in Clear Lake (the biggest natural lake in CA) IIRC include no more than 1 pound of LMB per month per person or something to that effect.

many mountain properties are built on old gold mining claims, and the ponds are thusly prone to high Hg. anybody who owns a pond in the Sierra Nevada should have it tested at least once for Hg before eating lots of fish out of it.

Boomer2,

To comment on this aspect of your question...we have cattle and ponds and the one pond that we designate for fish consumption, we fence off from the cattle. We don't feed any growth hormones or anything unnatural to the cattle, but still feel that fish have a much better taste if the pond waters are not subject to cattle use. If there was a feed lot feeding growth hormones or other chemicals to cattle in the watershed for a pond, I think I wouldn't eat those fish...just my personal opinion.

Thanks everyone for all your replies. If properly managed and depending on the location, I get the impression that pond fish are safe to eat.

I see most here feel that fertilizing a pond will greatly benefit the fish and their growth. Does anyone here worry about dangerous chemicals from fertilizers getting into the fish? Is there an alternate organic method to fertilizing a pond?

dangerous chemicals? The recommended fertilizers have no trace elements and contain mostly, if not all, phosphorus. In a mature pond, triple phosphate works quite well, assuming you have enough water hardness for it to be active. As far as organics, if you feed your fish and overfeed, that would apply nutrients to the pond.....at the risk of reduced water quality, possible O2 crashes, among others.

Nothing more organic than cow manure. However, I have no idea how to compare it to chemicals. I don't use either. I don't need it and can't count on my water levels staying static enough to push the envelope on carrying capacity.

Fertilizer of any kind will benefit an infertile pond. However, if you don't need it, don't do it.