Today a crew from the University of St. Thomas and the St. Croix Watershed Research Station brought me along to help take some samples from the bed of Upper Prior Lake.
First order of business was getting there, equipment in tow:
Once we found the right spot, the crew swung into action like the well-oiled machine they are, laying out equipment, drilling holes, and taking measurements.
Possibly the most important piece of equipment was the corer itself. This hollow tube was driven into the bed of the lake, extracting and preserving a vertical section of sediment that contains the geological and ecological history of lake.

Will Hobbs of the St. Croix Watershed Research Station demonstrating a sediment coring tube to St. Thomas students.
The extracted core included bands of lighter and darker material, as well as invertebrate-built structures on the surface of the lakebed that remarkably survived the extraction process; unfortunately, at that very moment, my camera battery decided to die.
While the cold drove me off the ice around 11:00 AM, the St. Thomas and Research Station crew spent most of the day on the lake, taking multiple cores deep into the lake bed and at multiple locations. They will use these cores to reconstruct the history of the lake, from sediment accumulation to algae growth. That history, in turn, will allow us to understand what is possible and what is not possible with Upper Prior Lake, and allow us to make better choice in the future.