During my Masters, I worked to reconstruct (paleo)productivity trends in Lake Superior over the last 10,000 years using bulk organic carbon and nitrogen elemental abundances and stable isotopes, as well as compound-specific stable isotopes of carbon.
Recent studies have documented changes in Lake Superior’s physical, chemical, and biological processes – including a 3.5°C warming of the surface waters over the last century. Such changes are often difficult to perceive as cause for concern when not placed within a historical context. The aim of this research was to reconstruct trends in primary productivity in Lake Superior over the last 10,000 years using bulk and molecular biomarker proxies of sedimentary organic matter, with an emphasis on changes in the last 200 years. Our efforts ultimately provided a historic baseline on which to assess anthropogenically induced changes in Lake Superior.