How are fish poisoned by Mercury? What can we do about it?

It's been a common thread in the topic of fish that you shouldn't eat too much of any one kind due to mercury poisoning. We've heard this caution for so long many people are left thinking it's just a fact of life, and we aren't questioning how to make this better. So where do we start?

The two biggest problems we face with this issue are first, that mercury is not only distributed into the fishes systems by man, but also by nature. And second, that mercury does not pass through the fishes digestive system, it stays there and gathers over time until the toxicity is so high that the fish either dies or infects other fish around it. (For more information on the origins of mercury in fish, please click here.)

The largest portion of mercury is introduced into the fishes habitat through chemical plants, coal-fired power plants, cement plants and steel production plants. It is released into the air or water supply and makes its way into rivers and oceans, giving the fish small to large doses of mercury every day. The larger fish have a higher chance of mercury poisoning through the food chain; A small fish gets mercury into its system and is eaten by a larger fish. This larger fish eats many small fish, each with a low level of mercury. Over time, the small amounts of mercury in all the smaller fish build in the large fish until it dies, or is caught and sold to humans for consumption.

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So what are some preventative measures we can take to keep mercury out of the water supply and effectively out of the fishes digestive system? One promising start is to filter the mercury out of the waste at the power plant it's produced at. There are several methods, one being a simple filter to catch mercury particles that would have entered into the air. Others being similar filters for water and waste treatment to specifically attract mercury particles out. (Even some as small as a sponge!)

On an individual level, we need to practice moderation when eating certain types of fish. The Natural Resources Defense Council and FDA websites have very helpful charts to tell what fish are the most or least toxic. The NRDC even categorized them by level of toxicity, you can find that information here. The more we learn the healthier we can be!