09-22-2013, 02:07 AM
Of course, I can avoid mercury from fish by not eating them or get less by eating less as in your smaller portions suggestion. But, that is not the equivalent of my choice to eat smaller fish.
Fish is a healthy food. Though mercury is poison, I can get much less by being selective in eating smaller fish even with large portions. Here's why:
A pound of fish meat from small fish contains much less mercury than a pound of fish meat from a big fish that eats the small fish because of bioacculation.
The mercury in the environment, perhaps at very low levels, is taken up by tiny living things. Small living things are eaten by larger living things and those are eaten by larger fish and so on.
Each time the mercury of all the food is concentrated into what becomes the next food for something bigger. The ones at the top of the food chain are gaining all of the mercury of the smaller fish it eats. It takes many pounds of small fish as food for a big fish for it to increase it's weight by just one pound, so that pound of fish meat from a big fish contains the contaminants of all those smaller fish it ate to bioaccumulate to a considerably much greater amount.
Numbers and concept in the following example is for a conceptual mathematical demonstration of the magnitude of biocumulation only as it doesn't contain real data nor does it account for the percentage of toxins that aren't absorbed nor the percentage that can be eliminated.
If ten pounds of plankton are consumed by growing bugs, then that might make only one pound of bugs. Growing minnows eat the bugs and it might take ten pounds of bugs to make just one pound of minnows.
In the above over simplified example of just the math of bioaccumulation, already mercury is concentrated a thousand times!
But, we don't eat minnows (and I haven't, yet ...). Minnows are eaten by larger fish. If ten pounds of minnows are needed to make one pound of larger fish, then the bioaccumulation of mercury at this point in this rough mathematically illustrative yet not actual example is ten thousand times! Still these are small fish.
The big fish we often catch and eat are at the top of the food chain and can have concentrated mercury a million times or more!
http://en.m.wikipedia.org/wiki/Bioaccumulation
http://www.onelook.com/?w=bioaccumulation&ls=a
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Fish is a healthy food. Though mercury is poison, I can get much less by being selective in eating smaller fish even with large portions. Here's why:
A pound of fish meat from small fish contains much less mercury than a pound of fish meat from a big fish that eats the small fish because of bioacculation.
The mercury in the environment, perhaps at very low levels, is taken up by tiny living things. Small living things are eaten by larger living things and those are eaten by larger fish and so on.
Each time the mercury of all the food is concentrated into what becomes the next food for something bigger. The ones at the top of the food chain are gaining all of the mercury of the smaller fish it eats. It takes many pounds of small fish as food for a big fish for it to increase it's weight by just one pound, so that pound of fish meat from a big fish contains the contaminants of all those smaller fish it ate to bioaccumulate to a considerably much greater amount.
Numbers and concept in the following example is for a conceptual mathematical demonstration of the magnitude of biocumulation only as it doesn't contain real data nor does it account for the percentage of toxins that aren't absorbed nor the percentage that can be eliminated.
If ten pounds of plankton are consumed by growing bugs, then that might make only one pound of bugs. Growing minnows eat the bugs and it might take ten pounds of bugs to make just one pound of minnows.
In the above over simplified example of just the math of bioaccumulation, already mercury is concentrated a thousand times!
But, we don't eat minnows (and I haven't, yet ...). Minnows are eaten by larger fish. If ten pounds of minnows are needed to make one pound of larger fish, then the bioaccumulation of mercury at this point in this rough mathematically illustrative yet not actual example is ten thousand times! Still these are small fish.
The big fish we often catch and eat are at the top of the food chain and can have concentrated mercury a million times or more!
http://en.m.wikipedia.org/wiki/Bioaccumulation
http://www.onelook.com/?w=bioaccumulation&ls=a
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