Accession Number : ADA303618

Title :   Water Operations Technical Support Program. Direct and Indirect Influences of Aquatic Macrophyte Communities on Phosphorus Mobilization from Littoral Sediments of an Inlet Region in Lake Delavan, Wisconsin.

Descriptive Note : Final rept.,

Corporate Author : ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MS ENVIRONMENTAL LAB

Personal Author(s) : James, William F. ; Smith, Craig S. ; Barko, John W. ; Field, Stephen

PDF Url : ADA303618

Report Date : SEP 1995

Pagination or Media Count : 29

Abstract : Lake Delavan, Wisconsin, has been the subject of extensive lake restoration to control phosphorus (P) and reverse eutrophication (O'Reillly 1992). Efforts over a 5-year period (1986-1991) to improve deteriorating water quality in this lake have included diversion of septic systems and control of nonpoint sources of P in the watershed, construction of an in-lake dike and modification of the dam and outlet structure to divert external P and sediment loads from the main body of the lake, the development of wetlands and sedimentation pools along the main tributary inflow of the lake to reduce sediment loading, a hypolimnetic alum treatment, and complete eradication and restocking of the fishery to promote top-down control of phytoplankton biomass. While the preliminary results of these actions have indicated a marked improvement in the trophic state of the lake, concerns have arisen over the development of extensive submersed macrophyte beds in the inlet region of the lake following restoration and improved water clarity. Associated with the macrophytes in the inlet region of the lake, oftentimes extremely high total P concentrations (range = 0.09 to 0.87 mg/l Holmstrom, Kammerer, and Ellefson 1994) have been measured during the summer. Macrophytes can mobilize sediment P via root uptake and senescence (Barko and Smart 1980; Carpenter 1980; Smith and Adams 1986) and by altering water chemistry in ways that affect rates of P release from the sediments (James and Barko 1991). Species composition, biomass, and nutrient content of submersed macrophytes in the inlet region of Lake Delavan were evaluated at the approximate peak in biomass to estimate the macrophyte P pool and its potential for P loading to the inlet region.

Descriptors :   *AQUATIC ORGANISMS, *PHOSPHORUS, *LITTORAL ZONES, *LAKES, *AQUATIC PLANTS, CONTROL, PEAK VALUES, MOBILIZATION, MODIFICATION, WATER, AGING(PHYSIOLOGY), NUTRIENTS, REGIONS, ESTIMATES, OXYGEN, REVERSIBLE, LABORATORIES, FLOW, WETLANDS, WATER QUALITY, INLETS, SEDIMENTS, CONCENTRATION(CHEMISTRY), DISSOLVING, SUMMER, SEDIMENTATION, STREAMS, PHYTOPLANKTON, WISCONSIN, DAMS, BIOMASS CONVERSION, WATER CHEMISTRY, MALNUTRITION, ALUMS, EUTROPHICATION.

Subject Categories : Biochemistry
      Biology
      Physical and Dynamic Oceanography

Distribution Statement : APPROVED FOR PUBLIC RELEASE