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Articles by OSU researchers that are part of a larger effort to understand baleen whales' diet and physiology. This research uses nonlethal and minimally invasive monitoring techniques (i.e., analyzing feces, respiratory vapor, blubber biopsy, drone images). While all these techniques individually provide slices of information on whale health, if these approaches are employed simultaneously, a more robust and complete assessment of the whales may be feasible, including the potential to cross-validate these methods. A more complete understanding of these whales will also assist efforts to mitigate impacts at an individual and population level.
This research focuses on approximately 250 Eastern North Pacific (ENP) gray whales, known as the Pacific Coast Feeding Group (PCFG). This group has a smaller migration range that runs from the northern California coast during the winter to southeastern Alaska in the summer. These whales are frequently located within 10 km of the shore and are subject to human pressures, including coastal pollution, ambient noise, fishing gear entanglement, and vessel/ship strikes.
This research is funded in part by a development grant from Oregon Sea Grant. The lead researcher is Leigh Torres, an Associate Professor in the Department of Fisheries and Wildlife and an Oregon Sea Grant Extension Marine Mammals Specialist.
(photos courtesy of Leigh Torres)
Do Gray Whales Count Calories? Comparing Energetic Values of Gray Whale Prey Across Two Different Feeding Grounds in the Eastern North Pacific
Lisa Hildebrand | Kim S. Bernard | Leigh G. Torres
Researchers looked at the energy values of common nearshore zooplankton in Oregon's PCFG gray whale feeding grounds. They compared them to the energetic value of amphipod species fed on by ENP gray whales in the Arctic. Their findings indicate the energy value of food sources found off the Oregon coast, specifically Dungeness crab megalopae, is higher in calories than the predominant Arctic amphipod. However, research suggests that other factors, such as prey density, the amount of energy it takes to feed, or the fidelity of forging sites, play a role in the differences in populations sizes of the two groups of gray whales.
Stressed and slim or relaxed and chubby? A simultaneous assessment of gray whale body condition and hormone variability
Leila S. Lemos | Amy Olsen | Angela Smith | Jonathan D. Burnett | Todd E. Chandler | Shawn Larson | Kathleen E. Hunt | Leigh G. Torres
Reports on research investigating the effects of body condition variability on hormones associated with stress and energy allocation in ENP gray whales. These findings indicate that the use of simultaneous gray whale physiology data is a valuable tool to understand the whales' bioenergetic strategies for coping with predictable and unpredictable dietary shifts.