Accession Number:

ADA229509

Title:

Effects of Alum Treatment on Phosphorus Dynamics and Phytoplankton Response in Eau Galle Reservoir, Wisconsin

Descriptive Note:

Final rept.

Corporate Author:

ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MS ENVIRONMENTAL LAB

Report Date:

1990-09-01

Pagination or Media Count:

48.0

Abstract:

The hypolimnion of Eau Galle Reservoir, Wisconsin, was treated with aluminum sulfate alum in 1986 to reduce excessive phytoplankton production associated with high phosphorus loading from anoxic, profundal sediments. Prior to treatment, internal total phosphorus TP loading was 3 to 6 time greater than external TP loading during summer stratification. Periodic increases in epilimnetic TP mass and chlorophyll alpha concentrations closely corresponded with elevated internal TP. For 1 year following treatment, internal TP. For 1 year following treatment, internal TP loading and concentrations a soluble reactive phosphorus in te hypolimnion were substantially reduced. Following alum treatment in 1986, phytoplankton biomass was less than half that occurring during the previous year however, it was not significantly different from other years. Subsequent to several years of codominance with blue-green algae, the dinoflagellate Ceratium hirundinella assumed singular dominance in 1985. With the exception of this change in relative dominance maintained through 1988, the phytoplankton community of Eau Galle Reservoir has been remarkably stable, despite effects of a winter drawdown in 1986, and climatic wet versus dry extremes over the 8-year study period. Without a decrease in phosphorus availability, Ceratium and blue-green algae are likely to persist as codominants during the summer in this system for many years. TTL

Subject Categories:

  • Hydrology, Limnology and Potamology
  • Water Pollution and Control

Distribution Statement:

APPROVED FOR PUBLIC RELEASE