Richard C. Lathrop

Eutrophication and its management in the Ya-hara Lakes near Madison, Wisconsin (USA)

Eutrophication of the four Yahara River chain of lakes Mendota, Monona, Waubesa, and Kegonsa otherwise known as the “Madison lakes” (Wisconsin, USA), has been dramatic since the mid-1800s. For Lake Mendota, the damming of the lake’s outlet plus the agricultural expansion of its watershed resulted in blue-green algal growths. These impacts, however, were dwarfed by water quality problems stemming from Madison’s wastewater inputs that directly entered Lake Monona from the late 1800s through 1936, and then Lake Waubesa until 1958. Blue-green algal blooms were so bad in the lower Yahara lakes that major copper sulfate treatments were conducted during 1925–1954. Mendota’s algal blooms were not a problem until the mid-1940s when wastewater inputs from upstream communities increased as well as the agricultural use of nitrogen (N) and phosphorus (P) fertilizers. After wastewater diversion in 1971, blue-green algal blooms persisted in Lake Mendota, and the onus of the problem shifted to agricultural and urban nonpoint source pollu-tion. While much progress has been made in recent years to control these pollution sources to Men-dota, animal manure has developed into a major management problem. Another emerging problem is tied to climate change and the resulting increase in frequency of extreme precipitation events that lead to much greater runoff P loadings. This presentation will summarize the eutrophication history of the Yahara lakes by presenting long-term data and will describe new initiatives to further control runoff P sources including proposals to build anaerobic digesters with manure P capture capabilities

Speaker's profile

Dr. Richard Lathrop is a lake researcher for the Wisconsin Dept. of Natural Resources and holds dual honorary appointments with the University of Wisconsin–Madison (UW) Center for Limnology and the UW Gaylord Nelson Institute for Environmental Studies. Dr. Lathrop has conducted re-search on well-known Lake Mendota and the other Madison lakes for over 33 years and has authored many scientific publications about the eutrophication of the lakes and changes in their chemistry and biota. He currently is the Madison lakes field site manager for the UW’s North-Temperate Lakes Long-Term Ecological Research (LTER) project and is the lead scientist on other collaborative lake research/restoration projects including the Devil’s Lake hypolimnetic withdrawal project and the Lake Wingra carp removal project. He also is Co-Chair of the Science Council that will be directing Wisconsin’s efforts to assess the impacts of climate change as part of the newly formed “Wisconsin Initiative on Climate Change Impacts” (WICCI).

Ort

Großer Hörsaal
Müggelseedamm 310
12587 Berlin-Friedrichshagen 

© IGB 10/31/2008