Water Quality Information: Zebra Mussel Problem

Concerns people should have with regard to the population of mussels that are now inhabiting areas near pennsylvania. Insight into the problems they may bring with them.

Zebra mussels have just been discovered in the first inland lake in Pennsylvania. What could be so bad about the tiny organisms that are credited with improving the water clarity of neighboring Lake Erie? What does it mean that until very recently they have not successfully jumped the watershed into Edinboro Lake, but now are found inhabiting it? I mean, they're not killer bees? Right?

Killer bees they are not, but they have a profound effect on the ecological balance of our waterways. Zebra mussels(Dreissona polymorpha) disrupt the aquatic foodchain by removing nearly all the phytoplankton and zooplankton. When they take up residence in a body of water their population becomes so dense that they smother native mussels and crowd out other species. In the Great Lakes the density is 20,000 or more per square meter!

In Lake Erie the mussels are found at a density level of 6,000 or more per square meter. Even at this population they clog water intake pipes, underwater machinery and they foul boat motors. Clams have disappeared from Western Lake Erie due to the activity of these mussels. Due to the Zebra mussel's filtering activity, they have a high concentration of toxins which is passed on to any waterfowl that feed on them. The only natural control is a species of diving duck.

But, biologists and environmentalists are worried about more than clams at Edinboro. Their worry is that the Zebra mussels will have a bad effect on fish, fishermen, boaters and the community surrounding the lake. Zebra mussels, say the experts, could choke the life out of an ecosystem.

Because Edinboro Lake is a much smaller lake than Lake Erie, the effects of Zebra mussel is expected to be profound. Presently the "infestation" seems to be about 100 to 150 mussels per square meter, this according to Jim Grazio who is an aquatic biologist with the Department of Environmental Protection. Presently the plan is to try to contain the mussels in Edinboro Lake and not let them pass into Conneautee Creek, then French Creek and then into the Allegheny, Ohio and Mississippi rivers to further their damage to our waterways and our lake and river industry and recreation.

French Creek, which Edinboro Lake flows into, is one of the last refuges for many rare and endangered species. The Western Pennsylvania Conservancy lists the stream as having global significance in its near-intact pre-Colonization stream ecosystem. 26 species of mussels are residents of French Creek and two of the species, the Northern Riffleshell and the Clubshell mussel are federally listed as endangered species.



The Zebra mussels were discovered when some boats were pulled from the lake to be winterized. There were reportedly several thousand mussels on the bottom of one of the boats. This is the first time they have been found on an inland lake in Pennsylvania, although they have been residents of the Great Lakes since 1988.

Originally native to the Caspian Sea they were first discovered stateside in Lake St. Clair which is a connecting water body between lakes Huron and Erie. It is believed that they were introduced from the ballast of water of an oceangoing ship. Today they are likewise believed to travel as passengers on the hulls of

unsuspecting fishing and recreational boats.

Residents of Pennsylvania are asked to be careful when transporting their boats from one lake to another inland lake. The fear is that they will be carried into Lake LeBoeuf, Lake Pleasant, Canadohta Lake or Conneaut Lake . Here are some tips to try to stop the spread of these organisms.

1. If you find the mussels on the bottom of your boat, rinse the hull with hot water and leave the boat out of the water for five days. Zebra mussels can survive for up to five days out of water.

2. You may not know they are taking up residence in your bilge pump and your live-bait wells. These must also be flushed with hot water.

3. Check your trailer for water and drain it.

4. Don't transport the bait used in an infested lake to another waterway. A female zebra mussel can deposit more than a million eggs when zebra mussels spawn in June or July, and the small creatures start life as larva - so small that they are all but invisible. They get carried by the current and swim. Someone could have a bucket of what appears to be clear water, and it could have thousands of zebra mussel larvae in it.

5. Inspect your screens and water intakes for signs of the mussels.

If you happen to notice any signs of Zebra mussels in streams or small lakes in Northwestern Pennsylvania, please call Jim Grazio at the Department of Environmental Protection at the regional office in Meadville.

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