Mercury Rising
The Spread and Accumulation of
Mercury in the Marine Environment
By David Batcheller
(This webpage was created in partial fulfillment of my senior
seminar class)
http://en.wikipedia.org/wiki/Mercury_in_fish
Abstract
Mercury is a naturally occurring metal produced
through volcanic activity, forest fires, and erosion. Mercury (II) and methylmercury are two forms
of toxic mercury that can be harmful to both humans and wildlife at high
concentrations. High concentrations of
mercury can be especially harmful to the development of unborn babies and young
children. Extreme mercury poisoning can
lead to much more severe symptoms including death. Although mercury exists naturally in the
environment, 2/3 of the mercury present in the atmosphere and water surface
today originated from anthropogenic sources.
Due to increased mercury levels at the source and a process known as
biomagnification, fish and other aquatic organisms have become potentially
dangerous to eat in excess.
Biomagnification refers to the process by which a substance becomes more
concentrated at increasing levels of the food chain. Because methylmercury is not excreted easily,
organisms retain it until they are consumed and then transfer it to their
predator. As organisms higher in the
food chain feed more often, these organisms accumulate much more mercury at a
much faster rate. Therefore, people,
especially pregnant women and children, should be careful with the fish they
eat and avoid eating too much fish at higher trophic levels such as shark,
swordfish, king mackerel, or tilefish, or fish tested to have mercury levels of
1ppm or above.
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Further
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