Bright, R.C., E. Plummer, and D. Olson. 1988. A survey of the mussels of the Zumbro river drainage, southeastern Minnesota. Report submitted to the Minnesota Department of Natural Resources. 27+ pp.
A survey of the mussels of the Zumbro River drainage of southeastern Minnesota was made during the summer of 1988. Eighty-three sites were studied and 1184 specimens from 17 species were examined for size, condition, abundance, and distribution. Both transects and timed searches were employed to gather data.
Mussel density was found to be low but similar to that of the adjacent Cannon River.
Both density and diversity were high below dams as the results of fish congregating there. However, the dams disrupt the distribution of some fish serving as glochidial hosts.
Excessive siltation and unstable substrates appear to be the major limiting factor in the main stem of the Zumbro River, and long stretches are essentially devoid of mussels.