Calibrating temperature reconstructions from fish otolith oxygen isotope analysis for California's critically endangered Delta Smelt

Abstract

The species-specific δ¹⁸ O_otolith fractionation equation allowed for accurate and precise reconstructions of water temperatures experienced by Delta Smelt. Characterization of ambient δ¹⁸ O_water values remains a critical next step for reconstructing thermal life histories of wild Delta Smelt. This tool will provide new insights into habitat utilization, potential thermal refugia, and resilience to future warming for this critically endangered fish.