Clam This image courtesy of Montana State University Dept. of Biology Photographer Unknown

Original artwork by Andrew This original report may be found on the Radical Report Resources pages completed by the Web Weavers of Christiansburg Elementary School.

  There were several things about these animals that I wanted to learn. I wanted to find out what they ate and how they caught their food. I also wanted to know why they are endangered and how many species are endangered in Virginia.
 

  I soon learned that there was little information to be found. I had a lot of trouble getting information and also had trouble getting information I could understand. My father and I read the article from class together, and he explained the parts I did not understand.

  In the past, malacologists (scientists who study clams and mussels) have disagreed about the names of freshwater mussels since the early 1900s. This has caused a lot of confusion in trying to study them. In trying to solve this problem the American fisheries Society has published a list of acceptable scientific names for freshwater mussels. This should help them keep mussels straight.

  There are 73 species of freshwater mussels in Virginia. Twenty-eight of those species are endangered and six species are threatened with extinction. There are some species of mussels that used to live in Virginia, but no longer can be found there. Those species include the acorn shell, narrow catspaw, round pigtoe, pink mucked, and the cumberland bean. These species can still be found in other states. Most mussels on the endangered or threatened species list come from the upper Tennessee river drainage in southwestern Virginia.

  About 30 species of freshwater mussels in Virginia are endangered. As with most endangered plants and animals, loss of habitat is what is threatening the mussels in Virginia. There are three main things that have affected their habitats. First, the stream habitat has changed. This is due mostly to channelization and dredging of streams. Second, there is a decrease in the water quality of Virginia's rivers and streams. This is caused by pollution, toxic spills, and sedimentation. Third, there is destruction of the riparian habitat. This is the habitat along the stream and river banks is destroyed. The mussels' habitats are changed by erosion and cutting of vegetation along the stream bank. The habitat of freshwater mussels in Virginia has been affected since the first settlers arrived. Then they began to clear the forest and started agriculture activities that adversely affect stream and river habitats.

  Since freshwater mussels are attached to the bottom of the streams, this makes them immobile. When there habitat changes, they are unable to move to a better habitat like other species. This makes mussels especially vulnerable to these changes in their environment.

  Another threat to freshwater mussels in Virginia is the Asian clam. Over the last 10 years, it has been introduced in every major river system in Virginia. They are competing with the native freshwater clams and mussels for habitat survival. The Asian clam is now the dominant mollusk in many rivers. It is not known if the native mollusks will be able to coexist with this species.

Return to Mollusks page.

If you would like to add to these Endangered Species
pages then email your contributions to Christiansburg Elementary