Relatively little mussel survey work has been conducted in north central Minnesota (Graf 1997). The Continental Divide bisects the Chippewa National Forest. Two-thirds of the Forest drains to the Mississippi River basin, while one-third drains to Hudson Bay via the Big Fork River and Red River of the North.
Nineteen sites among sixteen streams in the Chippewa National Forest were surveyed for mussels. We used snorkeling equipment and water scopes to find mussels at each site. All mussels were identified and tallied at each site. Live mussels were returned to the collection site and dead shells were deposited at the Bell Museum of Natural History.
Seven species of live mussels were collected during the survey. The three most commonly observed species (in order of abundance) were fatmucket (Lampsilis siliquoidea), cylindrical papershell (Anodontoides ferussacianus), and giant floater (Pyganodon grandis). A few creek heelsplitter (Lasmigona compressa), pocketbook (Lampsilis cardium), white heelsplitter (Lasmigona complanata complanata), and paper pondshell (Utterbackia imbecillis) were also observed. Black sandshell (Ligumia recta) and flutedshell (Lasmigona costata) were collected as empty valves. Black sandshell, creek heelsplitter, and flutedshell are special concern species in Minnesota.
Of particular interest was the observation of two little known species from the Rainy River basin. A pair of flutedshell valves were collected at Rice River. This is only the second time flutedshell has been collected from the Rainy River basin. The other specimen was collected in 1997 from South Fork Coon Creek (Hove et al. 1997). We also collected paper pondshell in a tributary to Jessie Lake. Prior to this survey the paper pondshell was only known from literature records and Bell Museum vouchers collected from two locations on the Bowstring River (Graf 1997, Hove et al. 1997).
Literature Cited
Graf, D. L. 1997. Distribution of unionoid (Bivalvia) faunas in Minnesota, USA. The Nautilus 110(2): 45-54.
Hove, M., S. Strong, A. Jacobson, J. Schussler, and V. Kurth. 1997. Northern Minnesota river holds three state-listed mussels. Triannual Unionid Report. Report No. 13, p. 22.
Waters, T. F. 1977. The streams and rivers of Minnesota. University of Minnesota Press, Minneapolis, MN. 373 pp.