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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. 

Abstract Strontium isotope ratios (⁸⁷Sr/⁸⁶Sr) of incrementally grown tissues have been widely used to study movement ecology and migration of animals. However, the time scale of⁸⁷Sr/⁸⁶Sr incorporation from the environment into tissue and how it may influence data interpretation are still poorly understood. Using the relocation of a zoo elephant (Loxodonta africana) named Misha, we characterise and model the⁸⁷Sr/⁸⁶Sr turnover process using high‐resolution measurements of its tusk dentine. We seek to develop a framework that can improve quantitative interpretation of⁸⁷Sr/⁸⁶Sr data in tissues.The⁸⁷Sr/⁸⁶Sr transition associated with the relocation is measured using laser ablation inductively coupled plasma mass spectrometry (LA‐ICP‐MS) on a prepared tusk slab. We develop a turnover model (BITS), with a rapidly exchanging central pool and a slowly exchanging peripheral pool, in a Bayesian statistical framework. The measured dentine data are first used to calibrate model parameters. The parameters are then used to estimate possible⁸⁷Sr/⁸⁶Sr input time series from two datasets via model inversion: a fidelity test using Misha's dentine data and a case study using published dentine measurements from an Alaskan Woolly Mammoth (Mammuthus primigenius).The LA‐ICP‐MS data are consistent with a two‐compartment turnover process with equivalent half‐lives of 41 days for the central pool and 170 days for the peripheral pool. The model inversion shows good fidelity when estimating the intake⁸⁷Sr/⁸⁶Sr time series associated with Misha's relocation. In the case study, the model suggests an abrupt pattern of change in, and a much wider range of, intake⁸⁷Sr/⁸⁶Sr values than expressed in the woolly mammoth dentine data themselves.Our framework bridges the gap between environmental⁸⁷Sr/⁸⁶Sr variation and data measured in tusk dentine or other incrementally grown tissues. It could be coupled with movement models and additional isotope tracers to study seasonal residency or the spatial and temporal patterns of movement/migration. The generic turnover processes can be adapted to other isotope systems, additional incremental tissues, or other organisms, thus expanding our modelling toolkit to investigate niche partitioning, life history traits and behavioural patterns in conservation biology, archaeology and paleoecology. 

Publication version for the revised article in Methods in Ecology and Evolution Full Changelog: https://github.com/SPATIAL-Lab/BITS/compare/v.0.9.3...v.0.9.4