Freshwater Mussels
Freshwater
mussels are considered one of the most threatened groups of
organisms in the world. The small rivers of the tallgrass
prairie region of Oklahoma were once home to a wide array of
freshwater mussels. Studies in the 1920’s showed that the
Verdigris, Caney and Neosho Rivers in northeastern Oklahoma were
relatively good mussel habitat. However, since that time there
have been significant declines in mussel populations in these
rivers. Loss of native mussels has been attributed to habitat
alteration, pollution and invasive species.
Dr. Joe Bidwell and Ph.D. student Chad Boeckman at Oklahoma
State University began a study in the summer of 2006 to examine
mussel populations in the tallgrass prairie region. They sampled
31 sites, which had previously been sampled about ten years
earlier, from the Oklahoma-Kansas border to below Oologah Lake.
In 2007, they sampled 29 sites in the Caney River that had also
been examined ten years ago.
In the Verdigris River a significant increase in number and
amount of species was found in comparison with the 1997 study in
that area. Two species of mussels that were thought to have been
lost from the area were also found, the western fanshell and the
rabbitsfoot mussel. The western fanshell has a pattern of green
rays on its light brown shell and the rabbitsfoot mussel is
named so because of its shape.
In the Caney River it was determined that there had not been any
significant declines in mussel abundance since the 1997 study.
In addition to examining the freshwater mussel populations,
these researchers are also examining fish and invertebrate
populations in the area and looking for zebra mussels. Zebra
mussels are an invasive species of mussel that reproduce
rapidly. In zebra mussel infested waters it is not unusual for
native mussels to be completely covered by zebra mussels.
Competition for food and oxygen weakens and eventually starves
native mussels.
This study is ongoing, and will continue to examine the status
of invertebrates, fish and freshwater mussels in the tallgrass
prairie region of Oklahoma.