General information

The North Slope Borough Department of Wildlife Management, in cooperation with several other institutions (Northeast Ohio Medical University, Massachusetts Eye and Ear Infirmary, Kyoto University), has instituted a research program that is geared specifically towards investigating the sensory abilities of the bowhead whale (Balaena mysticetus). This work consists of four main projects that investigate audition (hearing), olfaction (smelling), gustation (tasting), and vision. Information produced by these projects will be used to help determine impacts to the species from industrial development and other anthropogenic sources, as well as provide critical anatomical baseline data. These projects are detailed and preliminary results are provided in the article cited below.

Research on Ear Anatomy and Hearing

Principal Investigators J. Craig George, Ph.D.
Collaborators AEWC, Hans Thewissen, Ph.D. (NEOMED)
Funding NSB-DWM, NSB/Shell Baseline Studies Program


The purpose of this study is to describe the normal anatomy of bowhead and beluga ears. Once understood, we eventually will attempt to attribute pathology and or injuries to them from a host of different sources. Such sources may include:

  • Age
  • Sonar
  • Seismic surveys
  • Marine Geophysical Surveys
  • Explosions
  • Acoustic deterrent devices
  • Winches/onboard machinery
  • Vessel noise (high and low frequency)
  • Ice breaking
  • Oceanographic research
  • Hunting
  • Development (on and offshore)
  • Aircraft

In the years 2008-2013, Hans Thewissen has examined the inner ears of several bowhead whales. Local whale hunters were invaluable in allowing Dr. Thewissen to take the inner ear parts from their whales. The project consists of two phases:

  1. Study and describe the normal anatomy of the bowhead whale ear.
  2. Investigate tissues for any evidence of chronic or acute auditory (ear) damage that may be age related and/or due to exposure to man-made noise.

Ear Bone Size Variation/ Left: Mass of earbone is 1063 g (2.3 lbs) from a 37’6″ bowhead. Right: mass of earbone is 510 g (1.1 lbs) from a 31’10” bowhead whale


Bowhead Tympanic Ear Bones used for Age Determination


Bowhead Whale Sensitivity to Sound

Bowheads are sensitive to anthropogenic sounds. Elders and experienced hunters told scientists that migrating bowheads are very sensitive to sounds produced by humans. There is concern that loud offshore activities could impact whales and hunting. Science is confirming this traditional knowledge.

Marine mammal and acoustical monitoring of Western Geophysical’s open water seismic program in the Alaskan Beaufort Sea

This study showed that migrating bowhead whales were essentially excluded from a circular zone (pink circle) with a 12 mile radius around a seismic operation. Sightings of bowhead whales were lower during seismic (figure C below) activity than without seismic (figure D below).

Reference: Richardson, W.J. (ed.). 1999. Marine mammal and acoustical monitoring of Western Geophysical’s open water seismic program in the Alaskan Beaufort Sea, 1998. LGL Rep. TA2230-3. Rep. from LGL Ltd. King City, Ont. and Greeneridge Sciences Inc., Santa Barbara, CA, for Western Geophysical, Houston, TX, and National Marine Fisheries Services, Anchorage, AK, and Silver Spring, MD. 390 pp


  • LGL Ltd. and Greeneridge Sciences Inc. 1987. Response of bowhead whales to an offshore drilling operation in the Beaufort Sea, autumn 1986. Report from LGL Ltd., King City, Ontario Canada and Greeneridge Sciences, Inc., Santa Barbara, CA for Shell Western E&P Inc., Anchorage, AK.
  • Brewer, K., M. Gallagher, P. Regos, P. Isert, and J. Hall. 1993. Kuvlum #1 Exploration Prospect: Site Specific Monitoring Program. Final Report. Prepared by Coastal and Offshore Pacific Corporation, Walnut Creek, CA for ARCO Alaska, Inc., Anchorage, AK.
  • Hall, J.D, M. Gallagher, K. Brewer, P. Regos, and P. Isert.1994. Kuvlum Exploration Area Site Specific Monitoring Program. Prepared for ARCO Alaska, Inc. Anchorage, AK, by Coastal and Offshore Pacific Corporation, Walnut Creek, CA.
  • Richardson, W.J., et al. 1995. Marine mammals and noise. Academic Press., San Diego, CA. 576 p.
  • Davies, J.R. 1997. The impact of an offshore drilling platform on the fall migration path of bowhead whales: a GIS-based assessment. M.S. Thesis, Western Washington University.
  • National Research Council (NRC). Cumulative Environmental Effects of Oil and Gas Activities on Alaska’s North Slope. 2003. National Academies Press. 288 pp.
  • Richardson, W.J. (eds.) 2006. Monitoring of industrial sounds, seals, and bowheads whales, near BP’s Northstar Oil Development, Alaskan Beaufort Sea, 1999-2004. [Updated Comprehensive Report, April 2006.] LGL Rep. TA4256A. Rep. From LGL Ltd. (King City, Ont.), Greeneridge Sciences Inc. (Santa Barbara, CA) and WEST Inc. (Cheyenne, WY), for BP Explor. (Alaska) Inc., Anchorage, AK. 328 p. + Appendices on CD-ROM.
  • Richardson, W.J. 2008. Monitoring of industrial sounds, seals, and bowhead whales near BP’s Northstar Oil Development, Alaskan Beaufort Sea, 1999-2004. LGL Rep. P1004 from LGL Ltd. (King City, Ontario), Greeneridge Sciences Inc. (Santa Barbara, CA), WEST Inc. (Cheyenne, WY), and Applied Sociocultural Research (Anchorage, AK) for BP Exploration (Alaska) Inc. (Anchorage, AK).
  • Koski, W.R., et al. 2008. Feeding by bowhead whales near an offshore seismic survey in the Beaufort Sea. Presented to the 60th International Whaling Commission. SC/60/E14.
  • Ellison, W.T., et al. 2012. A new context-based approach to assess marine mammal behavioral responses to anthropogenic sounds. Conservation Biology 26(1):21-28.
  • Hatch, L.T., et al. 2012. Quantifying loss of acoustic communication space for right whales in and around a U.S. National Marine Sanctuary. Conservation Biology 26(6):983-994.
  • Rolland, R.M. et al. 2012. Evidence that ship noise increases stress in right whales. Proceedings of the Royal Society Biological Sciences. Published online 8 February 2012. DOI: 10.1098/rspb.2011.2429.
  • Blackwell S.B., et al. 2015. Effects of Airgun Sounds on Bowhead Whale Calling Rates: Evidence for Two Behavioral Thresholds. PLoS ONE 10(6): e0125720. doi:10.1371/journal.pone.0125720.
  • Kim, K.H., and W.J. Richardson (eds.). 2016. Monitoring of industrial sounds, seals, and bowhead whales near Hilcorp’s Northstar oil development, Alaskan Beaufort Sea, 2015: Summary Report. GSI Report 521-1. Report presented to Hilcorp Alaska LLC, Anchorage, Alaska, by Greeneridge Sciences Inc., Santa Barbara, California and LGL Alaska Research Associates, Inc., Anchorage, Alaska.
  • Ellison, W.T. et al. 2016. Modeling the aggregated exposure and responses of bowhead whales Balaena mysticetus to multiple sources of anthropogenic underwater sound. Endangered Species Research 30:95-108. doi:10.3354/esr00727.

More Bowhead Sensory Research

Principal Investigators J. Craig George, Ph.D.
Collaborators AEWC; Cheryl Rosa; Hans Thewissen, Ph.D. (NEOMED)
Funding NSB

Summary from Rosa et al. 2009:

“Anthropogenic activities such as oil and gas development and commercial fishing and shipping have the potential to create environmental disturbance, noise, and chemical pollution, all of which may impact wildlife, including whales. These activities are expanding rapidly in the Arctic, therefore, it is important to determine impacts, so that injury to marine wildlife can be avoided or appropriate and effective mitigation measures can be developed.

Migratory deflections caused by seismic sound, shipping or discharged wastes in the water may result in avoidance of important feeding areas or, conversely, whales exposing themselves to injurious levels of sound in order to feed/mate/rest in areas that are biologically important. Deflection may also result in increased energy expenditure. All of these factors may lead to higher mortality or lower birthrates in these species. Seismic sound may interfere with inter- and intra-specific communication (“masking”) or cause temporary or permanent threshold shifts (hearing loss) and other physical damage to the auditory apparatus of exposed whales.

The NSB-DWM’s sensory research program has been developed around these concerns. These studies will provide a better understanding of the sensory world of the bowhead whale and the potential for impacts from sound, waste and other industrial discharges. These data will also provide needed baseline information to assist in impact analysis and the development and evaluation of mitigation measures.”

Picture above shows a bowhead whale brain in situ, or inside of the braincase of the bowhead skull. Dissection was performed by Hans Thewissen

Olfaction in Bowhead Whales

In 2009, Dr. Hans Thewissen returned to Barrow to study the olfactory sense, or sense of smell, of bowhead whales. With the help of Craig George, they were able to section the brain cavity and locate tissues used for olfaction or smell. Read more about this research in this flyer and in the journal article below.


Read the articles below for more on the story of bowhead sense of smell and Dr. Thewissen:

Go to this page for more information on TEK and bowhead whales’ olfaction or sense of smell.

Sensory Hairs in Bowhead Whales


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