| Sulfate-reducing bacteria change mercury (II)
into methyl mercury (CH3Hg) It is unclear
whether the transport of mercury from bacteria to plankton occurs via direct
consumption of bacteria or through osmosis. Mercury is transported
and magnified through the food chain from plankton to small fish to large
fish to human beings. Biomagnification occurs because large animals
eat large numbers of smaller organisms for long periods of time.
Factors such as the pH of the aqueous environment, the temperature of the
water, the amount of dissolved organic carbon, the numbers and types of
organisms at each trophic level all play into the system as variables.
In addition, there are other known and unknown variables which affect the
biomagnification process. |