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Dr. Mark Brenner, Department of Geological Sciences - Paleolimnology

Mark Brenner is a limnologist/paleolimnologist with special interests in tropical and subtropical lakes and watersheds. He is a Professor in UF’s Department of Geological Sciences and serves as Director of the Land Use and Environmental Change Institute (LUECI). He teaches courses in Paleolimnology, Limnology, Florida Lake Management, and Tropical Field Ecology, the latter in Mexico. He is Co-Editor-in-Chief of the Journal of Paleolimnology. More information can be found at: http://www.clas.ufl.edu/users/brenner/

Goals of the Paleolimnology component - Evaluate baseline (predisturbance) conditions in lakes relative to target NCC values and develop alternative strategies for setting numeric criteria.

(1) Compile existing paleolimnological data that demonstrate the range of trophic state responses to human disturbances.
(2) Evaluate baseline nutrient concentrations among Florida lakes and establish if such predisturbance nutrient values in some regions exceed proposed NNCs.
(3) Explore the potential for using paleolimnology to develop flexible NNCs for lakes.
(4) Train students in paleolimnological methods and interpretation.

This work will use the sediment record of historic trophic state change in Florida lakes to test whether application of rigid NNCs is appropriate. Previous paleolimnological investigations used multiple lines of evidence (e.g. nutrients, diatoms, animal microfossils, algal pigments) in 210Pb-dated sediment cores to infer historical nutrient concentrations in Florida water bodies. In some cases, human disturbances clearly increased nutrient concentrations, which in turn caused biological changes. Diatom assemblages have proven to be reliable estimators of past water column nutrient levels, and measurements of plant pigments, especially those that pertain exclusively to cyanobacteria (myxoxanthophyll and oscillaxanthin), have been used to demonstrate that proliferation of blue-green algae has been a recent phenomenon in many water bodies. Pertinent to the issue of NNC implementation in Florida is the paleolimnological finding that many lakes, especially those in phosphate-rich regions, have naturally high nutrient concentrations. This suggests that some lakes are naturally eutrophic and do not require “restoration” to a low-nutrient state.