Fish Biology

[Herbseesmoore]

When cleaning fish over the years I've often wondered what the silver, metallic looking substance is, its sort of vein like. It actually looks like mercury. How does mercury gather in fish, on the cellular level?

[GordMay]

Mercury occurs naturally in small amounts in the environment. But industrial pollution can produce mercury that accumulates in lakes, rivers and oceans.

Microorganisms in these bodies of water convert the inorganic mercury to a highly toxic form, called methyl mercury. Methyl mercury enters the aquatic food chain by binding with particles and sediment eaten by fish. Fish eat these microorganisms. Because they eliminate mercury at a very slow rate, mercury tends to accumulate in their tissues and organs.

Large fish that are higher in the food chain — such as shark, tilefish, swordfish and king mackerel — tend to have higher levels of methyl mercury than do smaller fish. Larger fish eat the smaller fish, gaining higher concentrations of the toxin. The longer a fish lives, the larger it grows and the more mercury it can collect.

[sailorboy1]

never ask too many questions about your food, especially if you like it