Baleen Whale Earplugs
Whale Earplug Research - Reconstructing Stress and Stressor Profiles in Baleen Whale Earplugs. This work is supported by DOD ONR and is in collaboration with Stephen Trumble. Usenko and Trumble routine collaborate with Charles Potter (Smithsonian Institution, Museum of Natural History), Richard Sabin (Natural History Museum London), Kamal Khidas (Canadian Museum of Nature), and Steinhart Aquarium, part of the California Academy of Sciences.
Reconstructing 150 years of stress in Baleen whales.
Baleen whale cortisol levels reveal a physiological response to 20th century whaling. Stephen J. Trumble, Stephanie A. Norman, Danielle D. Crain, Farzaneh Mansouri, Zach C. Winfield, Richard Sabin, Charles W. Potter, Christine M. Gabriele, Sascha Usenko. Nature Communications volume 9, Article number: 4587 (2018)
To understand the cumulative effects of multiple stressors on large baleen whales, it is imperative to quantify and understand both the types of stress (e.g., intrinsic, extrinsic and ecological drivers) and their relative contributions. Therefore, the long-term goals of this project are to reconstruct lifetime (i.e. birth to death, ~6-month resolution) stress and stressors profiles in baleen whales using their earplugs. Reconstructed chemical and elemental profiles were derived by combining markers of stress (i.e. cortisol) and stressors profiles with age and date estimates derived from the earplug. Specifically, markers of reproduction, aging (DNA), foraging (i.e. bulk carbon and nitrogen stable isotopes), community structural shifts (i.e. compound-specific amino acid stable isotopes), and pollution were assessed. Lifetime hormone profiles, which resembles repeat sampling, were baseline corrected and provided an opportunity to combine profiles from different individuals, species, and generations. Stress and stressor profiles were reconstructed from blue, humpback, fin, gray, and Minke whales. Here, we present 150 years of stress data and examine historical relationships between cumulative stress and industrial whaling as well as current trends in baleen whales. Additionally, we highlight the utility of this matrix to assess pregnancy rates, climate change, contamination, community structure, and the long-term health impacts of stress. The results of this study will contribute to improving mitigation strategies through improved assessments of the potential impacts of anthropogenic activity.