Collaborators:  Robert Suydam, John Burns, Doug DeMaster, and Glenn VanBlaricom
Summary: Our objective was to document aspects of age, growth and reproduction of eastern Chukchi Sea belugas.  We collected measurements and biological samples from most of the 688 beluga whales taken by subsistence hunters from Point Lay, Alaska from 1987 to 2005.  Hunters at Point Lay usually select larger, older animals, so few small, young whales were sampled in the harvest.
Publications

Community of Point Lay coming together for the harvest of beluga whales.

Community of Point Lay coming together for the harvest of beluga whales.

This bias for larger whales resulted in more males and fewer females being taken.  Our results so far indicate that younger aged whales of both sexes had similar lengths.  Color change from gray to gray-white to white has long been known to be age related.  We found that lengths in both sexes were comparable until the whales turned white.  In these white adults, males were longer than females, averaging 436 cm (or 14.3 feet) to the female average of 362 cm (or 11.9 feet). At any given time, about 30-40% of the adult females are pregnant, which indicates that they calve every 2 to 3 years.  We estimated a gestation (time spent developing in the uterus) of 454 days, slightly less than the known gestation period of captive females.  We estimated the age of first-time mothers to be about 8.5 years.  According to growth layers in teeth and other information, beluga whales probably live to be about 60-70 years of age. All of the information gathered in this study will be valuable for estimating the growth of the population, making sound management decisions for sustainable harvests, and evaluating potential impacts from climate change and industrial development.

See the Beluga Age, Growth and Reproduction Poster below for more information.

Here is a photo of a beluga tooth with arrows pointing to three growth layer groups (GLGs). Each GLG represents one year. (Photo credit: Kristin Laidre)

You can read more about research on aging belugas in the following journal article:

Lockyer, C., Hohn, A.A., Doidge, D.W., Heide-Jørgensen, M.P., and Suydam, R. 2007. Age Determination in Belugas (Delphinapterus leucas): A Quest for Validation of Dentinal Layering. Aquatic Mammals 33:293-304.

Suydam, R.S. 2009. Age, growth, reproduction and movements of beluga whale (Delphinapterus leucas) from the eastern Chukchi Sea. Dissertation. School of Aquatic and Fishery Sciences, University of Washington, Seattle, WA.

Waugh, D.A., R.S. Suydam, J.D. Ortiz, and J.G.M. Thewissen. 2018. Validation of growth layer group (GLG) depositional rate using daily incremental growth lines in the dentin of beluga (Delphinapterus leucas) teeth. PLOS ONE 13(1):e0190498. doi.org/10.1371/journal.pone.0190498.

More journal articles:

Noren, S.R., and R. Suydam. 2016. Navigating under sea ice promotes rapid maturation of diving physiology and performance in beluga whales. Journal of Experimental Biology 219:2828-2836. doi:10.1242/jeb.143644.

Poirer MC, Lair S, Michaud R, Hernandez-Ramon EE, Divi KV, J.E. Dwyer, C.D. Ester, N.N. Si, M. Ali, L.L. Loseto, S.A. Raverty, J.A. St. Leger, W.G. Van Bonn, K. Colegrove, K.A. Burek-Huntington, R. Suydam, R. Stimmelmayr, J.P. Wise, S.S. Wise, G. Beauchamp, D. Martineau. 2019. Intestinal polycyclic aromatic hydrocarbon-DNA adducts in a population of beluga whales with high levels of gastrointestinal cancers. Environmental and Molecular Mutagenesis 60:29-41  doi: 10.1002/em.22251

Stimmelmayr, R., T. Ferrer, and D.S. Rotstein. 2019. Persistent Mullerian duct syndrome in a beluga whale Delphinapterus leucas. Diseases of Aquatic Organisms 136:273-278.