Zebra mussels are filter feeders, and they are capable of filtering about one litre of
water per day while feeding primarily on algae. They were transported from
Europe as stowaways in the ballast water of transoceanic ships and pose
significant social, economic & ecological concerns for the Great Lakes and other
The zebra mussel disrupts natures food chain. They remove nearly all particle
matter, by removing significant amounts of plankton from the water. They
remove food for microscopic zooplankton, which in turn are food for fish larvae,
juvenile fishes, and other plankton-feeding forage fish. These forage fish support
sport and commercial fisheries. This competition for plankton, the base of the
marine food chain, could have a lasting effect on the fish populations of the Great
Lakes. Most rocky areas of Lake Erie are almost completely covered in the mussel
several inches deep. In a laboratory observation, the accumulation in these beds
makes a foul environment with very acidic water.
Positive/Negative Effects on the Ecosystem
In Lake Erie the zebra mussel has already reduced native mussels. The dirty
water will reduce energy reserves of fish because they have to work harder to stay
alive. It will also increase vulnerability to the other environment stresses. Such as
extreme water temperatures, lack of food, or parasites and disease. As zebra
mussel spread, they may eliminate rarer species of mussels.
The zebra mussel has improved the water clarity of Lake Erie. The filtering of
water may increase the exposure humans and animals have to organic pollutants.
Early studies have shown that the zebra mussel can accumulate organic
pollutants in their tissue to more then 300,000 times greater than concentrations
in the environment. They then deposit these pollutants in their waste. These are
then passed up the food chain so any fish or waterfowl who co
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