|
 Freshwater
fish of the St. Lawrence River are turning their noses up to their
usual menu of insects and crustaceans. Instead, they are feasting
upon toxic-filled European quagga mussels.
These mussels are referred to as the river's junk food. Researchers
are concerned that this change in diet might affect both fish growth
and impact other freshwater animals. In the study, after examining
the stomachs of fish, researchers were surprised to find that 60
percent contained mussel shells and whole mussels.
Poisonous Mussels Work Their Way up the
Food Chain
- Mussels are not considered an adequate source of nutrition for
fish
- They contain toxins such as PCBs and botulism toxin (food poisoning)
- These toxins might kill the fish or their predators
- Fish that eat mussels are contaminated by the toxins
- Tens of thousands of birds such as common loons and gulls have
died as a result of eating contaminated fish
The result of this food chain cycle is a high likelihood of humans
consuming contaminated fish. Although this study targeted the St.
Lawrence River, researchers believe this problem might have already
spread to other freshwater systems.
EurekAlert
September 23, 2004
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