Ed Golson Outdoor Education

zebra mussel

( Invasive Species )

Scientific Name: Dreissena polymorpha

Description:  This is an invasive mussel species to North America, particularly the Great Lakes. it is native to the Black Sea.  It arrived in the Great Lakes by surviving in the ballast of ships traveling here.  The zebra mussel is a black shelled organism with white stripes on its back. They look a lot like small clams. They only grow to about one inch long, but they have made a huge impact.

Habitat: These mussels live in freshwater ecosystems on the pipes and docks of many personal and industrial places. They will stick to just about any hard surface underwater. Unfortunately, they can now be found in just about all of Michigan's inland lakes in addition to the all the Great Lakes.

What is the problem?  Zebra mussels eat much of the micro-organisms in the water causing a great shift in the food web. Many of the native species that rely on the microorganisms for food just can't compete and end up getting pushed out of the habitat .  Even worse, the zebra mussels clean the water so well that the water becomes much clearer allowing more plants to grow. This may seem like a good thing, until dead plants start turning into a messy sludge and use up all the oxygen in the water as they decompose. Another problem with them is that they are clogging up drainage pipes creating billions of dollars in expenses as they are removed.   

Zebra mussels reproduce very quickly- a single female can create up to a million eggs in a single year. As a result they have the ability to take over aquatic habitats very quickly. Not only do they steal food from other mussels and clams, zebra mussels will often attach themselves to larger mussels in such large groups that the native mussels eventually can't open themselves up to feed.

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