Northwest Fisheries Science Center

Environmental Chemistry Projects


Gina Ylitalo
Program Manager
Staff Directory

Life history parameter modeling

Obtaining information on life history parameters, such as age, sex, reproductive status, and body condition, of individual marine mammals is important in describing their population structure, behavior, foraging ecology and health. For some species, these data are not easily obtained from living animals, so novel methods using non-lethal samples must be developed and tested to help describe these elements. The Environmental Chemistry Program, in collaboration with other research groups, has recently developed models to estimate the ages of North Pacific killer whales, as well as North Pacific and Northwest Atlantic humpback whales using fatty acid ratios in biopsy blubber. Additional research interests include describing nutritional status and calving intervals of these whale populations.

Recent Publications

Herman DP, Matkin CO, Ylitalo GM, Durban JW, Hanson MB, Dahlheim ME, Straley JM, Wade PR, Tilbury KL, Boyer RH, Pearce RW, Krahn MM 2008. Assessing age-distributions of killer whale (Orcinus orca) populations from the composition of endogenous fatty acids in their outer-blubber layers. Marine Ecology Progress Series 372: 289-302.

Herman DP, Ylitalo GM, Robbins J, Straley JM, Gabriele CM, Clapham PJ, Boyer RH, Tilbury KL, Pearce RW, Krahn MM. 2009. Age determination of humpback whales Megaptera novaeanliae through blubber fatty acid compositions of biopsy samples. Marine Ecology Progress Series 392: 277-293.

Key Partners

Cascadia Research Collective
Glacier Bay National Park and Preserve, National Park Service
National Marine Mammal Laboratory, Alaska Fisheries Science Center
North Gulf Oceanic Society
Provincetown Center for Coastal Studies
University of Alaska Southeast

Staff involved in the project

Bernadita Anulacion, Keri Baugh, Jennie Bolton, Daryle Boyd, Richard Boyer, Doug Burrows, David Herman, Jonelle Herman, Ron Pearce, Catherine Sloan, Jennifer Travis and Gina Ylitalo

Predicting the reproductive history and age of female SPERM whales from selective PCB and fatty acid ratios measured in their blubber biopsy tissues (click to enlarge)