Measuring Trends in Lake Superior's Productivity Based on Two Centuries of Sediment
Residual bits of long-dead algae promise to reveal how Lake Superior's fertility has changed from the days when Ojibwe trappers and French voyageurs rendezvoused around its perimeter, through an era of logging, until now. Researchers intend to extract a history of plant productivity from six sediment cores retrieved from the bottom of the lake.
They expect that the compounds and atoms within the first foot of these cores will illuminate at least three things: how the lake's photosynthetic species responded to an influx of phosphorous before wastewater treatment improved, the origin of the nitrogen that has significantly increased in the lake over the past century, and a clearer understanding of how humans have influenced the base of Lake Superior's food web. This information will help federal, state, provincial, and tribal agencies responsible for managing the Great Lakes interpret current environmental conditions and better prepare for the consequences of local and global climate change.