Invasion Of The Zebra Mussels Essay, Research Paper

Invasion of the Zebra Mussels

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 attach themselves to anything they find, including docks, boat ramps, and waste pipes. All the industries in the area now have to worry about scraping these mini-invaders off. Yet another problem they?ve created is contaminated drinking water. The intake pipes in Lake Michigan and elsewhere are covered with mussels. Without being removed, they contaminate water and move on to clog up city pipes. Still another problem is their colonization of rock reefs. With the mussels being several inches deep in places, their waste is poisoning the area and fish that would normally lay their eggs there must look elsewhere for nesting areas. Now natality is down and mortality is up. A final problem they cause is damage to property. By latching onto boats and other floating objects, they can and will damage them. They cause innumerable problems, so now the question has become one of prevention and removal.

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; they are out competing all the native species. They are such a good competitor in the Great Lakes community because they have no natural predators. Nothing eats them! Combined with the fact that they can exist nearly anywhere, this lets them breed and breed and not worry about anything other than breeding and eating, while local populations must concern themselves with escaping predators, finding food, finding shelter, and many other bothers simply to survive.

Overall, the Zebra mussels are bad for the Great Lakes biological community. Countless ill effects have been listed, and a single benefit has yet to be listed. They impact everything in the food chain with their negative effects. They eat the bottom of the local food chain, and the top has nothing to eat. They coat everything conceivable. They take up habitats, forcing local populations to look for new territories. Unless this incursion is fought back, the Zebra mussel may well be the cause of the destruction of large sections of the local ecosystem. Nothing nature has produced has the capability to combat them, so it is up to humans to save the Great Lakes ecosystem. Only time will tell what tactics we can develop, and whether they will be enough. Until that time, it seems the Zebra mussels are here to stay.