Stock Structure and Genetics

Principal Investigators J. Craig George, Ph.D.
Collaborators John Bickham (Purdue University), Phil Morin (NMFS), Geof Givens (Colorado State University)


At the 2002 IWC meetings, the genetic structure of the Bering-Chukchi-Beaufort Sea bowhead population was brought into question. Several scientists suggested that the BCB population could have been made up of several genetically distinct stocks. At the time the management of the BCB bowhead whales was based on the single stock hypothesis meaning that they were of one genetic, interbreeding population.

Preliminary genetic studies suggested that the BCB population could be made up of two or more stocks. If this were the case, then the management strategy might need to be altered, which could have affected the quota. Continued studies tested the multiple stock hypothesis. At the 2007 IWC meeting over 40 scientific papers were reviewed, including genetics, traditional knowledge, migration patterns and other studies. Due to the “weight of evidence” of all of the studies, especially genetics, the Scientific Committee agreed that “the available evidence best supports a single stock hypothesis for BCB bowhead whales.” This information was good news for the AEWC as it meant that the current management strategy was sufficient and that the bowhead quota for 2008-2012 was maintained.

Merlin Koonooka drilling a bowhead skull to collect tissue for genetics analysis

Bowhead whale in the picture above was taken at Gambell, Alaska, and the sample collected was used in a “stock structure” DNA study to determine if whales harvested at St. Lawrence Island might be genetically different from those taken at Barrow. The results suggested that the harvested whales from the two locations are from the same genetic stock.


Banner photo credit: Kate Stafford

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