Date of Award
11-1985
Culminating Project Type
Thesis
Department
Biology
College
College of Science and Engineering
First Advisor
Keith Knutson
Second Advisor
Wayland Ezell
Third Advisor
Henry Coppock
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.
Keywords and Subject Headings
aquatic, macrophytes, perturbation, Sauk River, Chain of Lakes, algae, phosphorus, nitrogen, water transparency, phytoplankton, turbidity, nutrient loading, water velocity
Abstract
The Horseshoe Chain of Lakes consists of a glacial lake basin divided into fourteen bay-like lakes impounded by the Cold Spring Dam. The Sauk River flows through a majority of the basin; this results in increased turbidity and nutrient loading as well as fluctuating water levels and water velocity within the basin. Aesthetic deterioration of the lake chain, due to increased aquatic macrophytes, resulted in· a need for baseline data on the aquatic macrophytes and the influence of the Sauk River on the system. Investigation of the aquatic macrophytes and perturbation of the Sauk River took place June through August 1984. This study included Browns Lake which is in close proximity to the Horseshoe Chain of Lakes. Macrophytes were identified to species and zonation within the lakes was mapped. Biomass and tissue analysis for nitrogen and phosphorus were determined from macrophyte samples.
Fifty-nine species of macrophytes were identified. Ceratophyllum demersum L. was the dominant submersed macrophyte, and it was found in all lakes including Browns. Frequency of macrophytes throughout the system was 30%. Frequency of macrophyte coverage in individual lakes varied from 88.8% in Becker Lake to 4.2% in Knaus Lake. Ninety-eight percent of all macrophytes were found at a depth of two meters or less. Submerged macrophyte coverage was 26.2% (2.6 x 10 6 m2) of the littoral zone, Average summer dry weight biomass varied from 0.81 g/m2 to 156.5 g/m2 in Knaus and Becker Lakes, respectively. Results on a system-wide basis for analysis of plant tissue, which was primarily Ceratophyllum demersum, was found to vary from 0.37% total phosphorus (TP) in Bolfing Lake to 1.86% TP in macrophytes from Koetter Lake. Percent total Kjeldahl nitrogen (TKN) ranged from 1.82% to 2.95% in macrophytes from East and Zumwalles Lakes, respectively.
Disturbances brought by the Sauk River included: fluctuating water levels and water velocity, turbidity from sediments and alga, and pollution including excessive nutrient loading. Horseshoe and Cedar Island Lakes displayed poor water transparency due to phytoplankton from the increased nutrients. All other lakes (except for Schneider, Mud, Long and Becker Lakes which are isolated and Browns Lake which is not connected to the system) are affected by turbidity and water flow.
Recommended Citation
Chmielewski, Timothy C., "Aquatic Macrophytes and Perturbation Due to the Sauk River in the Horseshoe Chain of Lakes, Richmond, Minnesota" (1985). Culminating Projects in Biology. 76.
https://repository.stcloudstate.edu/biol_etds/76
