A quantitative survey of the phytoplankton and water quality of the La Crosse, "Black" and Mississippi Rivers
A seven-month study of the phytoplankton populations and water
quality of the La Crosse and Mississippi Rivers and the back water
slough of the old Black River channel below navigation pool #7, hereafter
referred to as the "Black" River, was initiated on May 19, 1971
and terminated on November 20, 1971. Nine sampling stations were
chosen in such a manner as to monitor the different channels above
and below their point of convergence. Phytoplankton samples were
collected at 3 depths, while samples used in the determination of
chemical parameters were obtained at the 2 m depth.
Six major groups of algae were found in the study area. These were
the Chrysophyceae, Pyrrophyta, Euglenophyta, Bacillariophyceae, Chlorophyta
and Cyanophyta. The latter three made up the major portion of the
phytoplankton, both in numbers and diversity.
The "Black" and Mississippi Rivers were found to be similar with
regard to phytoplankton composition. The chemical parameters of the
two study areas were also similar, with the exception of total hardness.
It was observed that the total hardness concentration was lower in the
River than in the Mississippi River.
The La Crosse River presented a seemingly unfavorable set of
conditions for the maintenance of phytoplankton populations. The major
organisms of this river were various species of Ulothrix. This was
also the only genus to occur in bloom proportions in the La Crosse
River. The La Crosse River, besides being distinct from the "Black"
and Mississippi Rivers with regard to phytoplankton composition, was
also distinct from the latter two on the basis of turbidity and
School:University of Wisconsin-Eau Claire
School Location:USA - Wisconsin
Source Type:Master's Thesis
Keywords:limnology freshwater biology la crosse river wis mississippi wisconsin
Date of Publication: