| TODAY!!!! Tuesday, April 12,
Bachmann, Florida LAKEWATCH, School of Forest Resources and
Conservation, University of Florida |
|Seminar Title: Setting the numeric
nutrient criteria for Florida lakes; why one size does not fit all
|Time: 3:00 PM - 4:00 PM|
|Location: 209 Emerson Alumni
United States Environmental Protection Agency has established numerical nutrient
criteria for Florida lakes based on two assumptions. All biologically productive
lakes (eutrophic) are the result of man-caused additions of phosphorus and
nitrogen to less productive lakes (oligotrophic and/or mesotrophic), and that
all eutrophic lakes fail to meet their designated uses as established under
Florida law. An analysis of several
different kinds of data indicated that many Florida lakes are naturally
eutrophic and are not significantly different from their presettlement
condition. Natural geographic
factors such as geology, soils, and hydrology are the most important variables
determining nutrient concentrations.
An analysis of published studies on biological communities and the algal
toxin microcystin did not support the assumption that eutrophic Florida lakes
fail to meet their designated uses.
The current law will find that 65% of Florida lakes are impaired by
nutrients, with the result that a large amount of scarce resources will be
wasted trying to remove phosphorus and nitrogen from naturally eutrophic lakes.
Florida lakes can be grouped into six phosphorus zones and five nitrogen zones
for a more logical method of setting numeric nutrient criteria.
Dr. Bachmann joined the Florida LAKEWATCH program in 1993.
He had previously served 30 years on the faculty of Iowa State University where
he taught limnology and conducted research on lake eutrophication, nutrient
cycling, stream ecology, and quantitative relationships in lakes. In Florida, he
has looked at relationships between lake trophic states and fish populations,
scientific bases for determining eutrophication in large Florida lakes, the
application of the theory of alternative stable states to shallow Florida lakes,
the role of wind in resuspending lake sediments, the use of biocriteria for
evaluating lakes, and lake restoration strategies.