During 1998 and 1999, larval fish phenology, abundance, and diversity were characterized at 13 reaches in the Buffalo River and Sand Hill River, tributaries of the Red River of the North. Channelized reaches were less stable than unchannelized reaches, showing more overall variation and greater daily fluctuation in temperature and dissolved oxygen (DO), and a higher level of intermittent flow. These reaches also exhibited significantly lower larval diversity. Principal component analysis explained > 84% of the variance for the first two axes for larval catch, with axis 1 associated with channelization and axis 2 associated with temperature and DO. Fathead minnow (Pimephales promelas) was associated with channelized reaches, whereas spotfin shiner (Cyprinella spiloptera), common shiner (Luxilis cornutus), redhorse (Moxostoma spp.), and darters (Etheostoma spp.) were associated with unchannelized reaches in both years. Clear associations of reproductive guilds with channel type were not detected, but species of intermediate pollution tolerance were associated with unchannelized reaches and tolerant species were associated with channelized reaches.
Bibliographical noteFunding Information:
We thank Neal Feeken and Brian Nerbonne for assistance in field collections; Henry VanOfflen and the Minnesota Department of Natural Resource office at Detroit Lakes, Minnesota for their assistance and use of equipment. Gary Oehlert provided statistical guidance. Luther Aadland, Charles Beny, Henry Drewes, David Galat, and Bruce Menzel provided constructive comments on an earlier draft. Funding was provided by the Minnesota Department of Natural Resources through grant number M8110#77.