Evidence of multi-decadal behavior and ecosystem-level changes revealed by reconstructed lifetime stable isotope profiles of baleen whale earplugs

Biological time series datasets provide an unparalleled opportunity to investigate regional and global changes in the marine environment. Baleen whales are long-lived sentinel species integral part of ecosystem. Increasing anthropogenic terrestrial activities alter ocean systems, such alterations could change foraging feeding behavior baleen whales. In this study, we analyzed δ13C δ15N whale earplugs from three different (N = 6 earplugs, n 337 laminae) reconstruct first continuous stable isotope profiles with a six-month resolution. Results our study unprecedented assess behavioral as well ecological changes. Abrupt shifts temporal variability observed be indicative shift location and/or trophic level response natural or disturbances. Additionally, five out six individuals demonstrated long-term declining trends profiles, which suggest influence emission depleted 13CO2 fossil fuel combustion referred Suess effect. After adjusting values for estimated effect re-evaluating significant decline rate depletion contribution other sources that impact at base food web.