JASKOWIAK, MEGAN A.*, KAREN P. FAWLEY, and MARVIN W. FAWLEY. Department of Biological Sciences, North Dakota State University, Fargo, ND 58105. - An examination of the effects of a reservoir, Lake Ashtabula, on the periphytic algae in the Sheyenne River, North Dakota.
The Sheyenne River is a third order stream that drains a significant
portion of central and eastern North Dakota. In 1950, the Baldhill Dam
was built and as a result, the reservoir, Lake Ashtabula, was formed.
The periphytic algae in this river were extensively studied from
1997-1999. During this research, the effects of differences in
environmental variables on the algal communities were assessed with
Canonical Correspondence Analysis (CCA). In this analysis, the
periphytic algal communities in the downstream sites appeared to be
quite different from those communities found upriver of Lake
Ashtabula. Other research on different rivers has shown profound
changes in the algal community after a dam was built along the river.
Redundancy Analysis (RDA) was used to determine if the sites
downstream are more statistically similar with Lake Ashtabula than
with the upstream sites. Finally, CCA was used to examine which
environmental variables explain the most variance in Lake Ashtabula
and the downstream sites.
Key words: canonical correspondence analysis, North Dakota, periphytic algae, redundancy analysis, reservoir, rivers