BALEEN: Balaenopterids A Layered Exposures and Effects Nexus
Abstract
Predicting cumulative effects of multiple stressors on marine mammal populations is one of the most challenging and pressing issues of today. The physiological stress response and population impact when two or more stressors interact has not previously been described for marine mammals. The Smithsonian Institution baleen collection provides an unparalleled opportunity to investigate the interaction between two stressors in blue and fin whales, two species of interest to the DOD within their many areas of operations. The Smithsonian collection contains baleen plates from over 1,400 individual whales, with accompanying biological data, collected by Japanese commercial whaling hunts in the Ross Sea and northward during the 1946-47 and 1947-48 seasons. Numerous studies measuring hormones and stable isotopes have demonstrated that whale baleen, an accretionary keratin structure, provides a historical record that reflects biological and environmental conditions at the time of growth. We propose to assess foraging and movement as indicators of behavior change by measuring bulk stable isotopes retrospectively in baleen, and will infer food chain length from Compound Specific Isotope Analyses of Amino Acids (CSIA-AA). We will also simultaneously assess health by investigating energy storage and stress levels through measuring thyroid hormones and the glucocorticoids cortisol, corticosterone and aldosterone retrospectively in baleen. Vital rates will also be assessed by determining fecundity from retrospective baleen analyses of the reproductive hormones progesterone, estradiol and testosterone. The length of baleen plates from individual Antarctic blue and fin whales captured in 1946-48 represents the historical period of ~1941-48. This coincides with an extreme El Nino event and an Antarctic Oscillation negative phase shift, which produced significant warming in West Antarctica (~1942-1946). This major warming event (1st Stressor) likely impacted Antarctic krill recruitment and density as well as whale reproductive output during the 1940s. A second stressor was added in late 1945 when large-scale commercial whaling quickly ramped up at the end of World War II (WWII) (2nd Stressor). We anticipate that constructing historical trajectories from the baleen of known blue and fin whales will signify the most detailed investigation of the interaction between two stressors (warming event + whaling) on any marine mammal to date, while providing two case studies for application of the Population Consequences of Multiple Stressors (PCoMS) framework to actual marine mammal populations.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 05, 2021
- Source ID
- N000142112642
Entities
People
- Kristi West
Organizations
- Office of Naval Research
- United States Navy
- University of Hawaiʻi System