Mercury in the Everglades
Everglades Background Information:
* Established in 1947 on 1.4 million acres in southwest Florida
* Sunny, Semi-Tropical Swamp Setting. Experiences near daily downpours
Mercury's Effect on the Everglades:
* A small amount of mercury is found in the crust of the earth. This is not the problem. The anthropogenic mercury is the problem.
The mercury that is growing dangerously in size is known as methylmercury. It is an organic substance that still baffles scientists who are trying to work out its life cycle. So far, what they know is that methylmercury forms when inorganic mercury combines with organic matter that is dissolved in water. This reaction favors conditions that are extremely warm, where there is plenty of sunlight, and where the right kind of bacteria is present (mainly sulfate reducing bacteria). The Everglades, unfortunately, because of its large amount of sunlight and the near daily downpours provides ideal environment for forming methylmercury.
* Mercury settlement:
The majority of mercury sett;es into the surface sediment where the amount of mercury was2.5 times more than the deep sediment. This of course leads to an even greater chance of the mercury getting recycled into the food chain rather than decomposing.
Methylmercury becomes deadly to the environment through the process of biomagnefication. To achieve biomagnefication, the mercury must be consumed by microorganisms nd work its way up the food chain increasing in concentration as it enters larger and larger organisms. Methylmercury enters the food chain of the Everglades through plankton, which eats the methyl mercury loaded bacteria. The plankton is then consumed by slightly larger invertebrate animals. These invertebrates soon become dinner for much larger invertebrates such as snails, shrimp, and then fish. These in turn are then consumed by larger fish who become eaten by land dwelling animals such as raccoons, birds, alligators, panthers, and finally humans. With each step in the food chain, the concentrations of methyl mercury increases by ten. Thus it is the accumulation of the methylmercury, as a result of the biomagnefication, that is deadly.
* Effects of the influx of Methylmercury:
1. Death of three panthers
2. Declining number of wading bird, otter and mink populations
3. Toxic levels of mercury...