Effects of River Current Inflow on Dissolved Oxygen and Temperature of Refuge Zones for Cisco in Lake Bemidji

Authors

Bryant C. Swenson

Document Type

Article

Abstract

The objectives of this study were to (1) determine if the inflow current from the Mississippi River affects temperature and dissolved oxygen in Lake Bemidji, (2) determine how the amount of suitable cisco Coregonus artedi habitat changes over the summer in Lake Bemidji, and (3) predict how much cisco habitat would be available under a climate warming scenario. Summer fish kill of cisco occurs in most years on Lake Bemidji resulting from low dissolved oxygen in the hypolimnion and high water temperatures in the epilimnion. Dissolved oxygen and temperature profiles provided evidence to suggest the north basin is more suitable for cisco than the south basin containing the Mississippi river inlet. Throughout the sampling period, on average 52.73% of the north basin cross section was suitable for cisco compared to 40.91% of the south basin cross section. An increase in water temperature of 1°C for the climate warming simulation lowered the average percentage of suitable habitat for cisco in the north and south basin cross sections to 22.73% and 22.73%, respectively. The Mississippi River increased water temperatures between 1.5 to 2.5°C near the inlet and outlet. This increase in water temperature decreased the dissolved oxygen concentrations between 1 to 2 mg·L^-1 near the inlet and outlet of the south basin.

Publication Date

2014

Comments

Faculty sponsor: Dr. Andrew Hafs, Department of Biology, Aquatic Biology Program

Recommended Citation

Swenson, Bryant C., "Effects of River Current Inflow on Dissolved Oxygen and Temperature of Refuge Zones for Cisco in Lake Bemidji" (2014). Journal of Earth and Life Science. 49.
https://pines.bemidjistate.edu/j-earth-life-sci/49