Changing Dissolved Organic Carbon, Water Transparency and Thermal Structure in Boreal Lakes of the Northern US

Kelsey Boeff, Robert Brown, Kristin Strock, Nora Theodore, Kate Warner

Collaborators: Bill Gawley (Acadia National Park), Sarah Nelson (UMaine), Dan Engstrom & Mark Edlund (St Croix Watershed Research Station)

Project Summary

Many lakes in New England are undergoing a process referred to as “brownification”, in which the tea-colored stain in lakes from dissolved organic carbon (DOC) is increasing. While increasing DOC concentrations have been documented in many lakes in the Northeast, it remains unclear whether these changes are affecting the physical and biological structure of lakes. The objectives of this project are to determine the extent to which increasing DOC concentrations are altering water clarity and lake thermal stratification patterns.

We are employing various methods to assess these changes. Diatom fossils from lake sediments are being used to reconstruct changes in lake stratification patterns. Long-term monitoring of the biogeochemistry of a suite of remote lakes in Maine is also being conducted. We have also formed a partnership with Acadia National Park to assess changes in their lake ecosystems.

This research is being conducted in Maine as well as on Isle Royale, Michigan. It is funded by several grants, including funds from the US EPA, the Water Resources Research Institute, and an NPS George Melendez Wright Climate Change Fellowship.

 

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