There has been an incursion into the sovereign territory of the United States of America. The Zebra mussel, an animal much akin to the clam, has colonized nearly every hard surface in the Great Lakes area, and many rivers and streams attached to them. These invaders arrived on ships from England, pumped out through the ballast. Zebra mussels are from a different environment (England), thus they are classified as an exotic species. These pesky animals threaten the entire Great Lakes ecosystem.
The invasion has created many problems for the local ecosystem. First of all, Zebra mussels take the food for which native species already compete. Each mussel consumes about a liter of different types of plankton. Small fish lose their food, and their numbers dwindle. Big fish no longer have small fish to eat, and the entire food chain is disrupted. Now that the natives don't have enough food to go around, mortality rates are going up and they are starting to die out. Another problem they've created is clogging on industrial units. They reproduce en mass and attac
Several methods are being used to attempt to prevent the mussels from establishing themselves, and to try to reverse the problem. One method being tried is protective coatings on surfaces, such as paints containing TBT or copper have been tried. The problem with this is the paints often erode aluminum and other materials, and some are even illegal. Another method is heat. Zebra mussels are extremely sensitive to heat. They have a 100% mortality rate after 5 hours at 90°, or after only 15 minutes at 104°. The problem with this method is simply the fact that it is hard to apply. A final approach that has been tried is the application of chlorine. The chlorine works well in wells and bilges, but cannot be applied to lakes or streams due to its nature of being toxic to living things. The mussel's history in England is no help, for they have native predators there, diving ducks for example, that help control them. Populations of ducks like these European ducks in the Great Lakes are small, so our situation is quite different from theirs. Some method must be developed to combat these invaders; t
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