Multi-Millennial Context for Post-Colonial Hydroecological Change in Great Salt Lake

Abstract

Terminal saline lakes are environmentally sensitive systems that are sentinels for anthropogenic change. Understanding recent changes in these systems is complicated, however, by a lack of data documenting their natural variability and past response to human disturbance. Isotopic data from shallow sediments of Great Salt Lake (GSL), UT, demonstrate a two-phase shift in lake water and carbon budgets during the past 200 years. I suggest that these changes are associated with regional colonial settlement, which altered carbon budgets beginning in the mid-19th century, and the hydrographic effects of a railroad causeway built in 1959. The post-colonial isotope changes are unprecedented in the preceding ∼2,000 years and unusual in the context of an 8,000-year record of natural variability. This work illustrates the utility of proxy data in identifying past human impacts on saline lake systems and documenting background states that can serve as targets for management.