CETACEAN ASSESSMENT AND ECOLOGY PROGRAM:
Bowhead Whale Data
In June/July 2004, the International Whaling Commission (IWC) will be conducting
an Intensive Assessment of the western Arctic stock of bowhead whales (Balaena
mysticetus). As a part of the assessment, all relevant data was prepared
for any reanalyses that might be required in the intervening months.
Between 1976 and 1998, the NMML and LGL (environmental research associates)
collected aerial photographs of bowheads during the spring migration near
Barrow, Alaska, as well as during the summer in the Beaufort Sea. Data
from these photographs have been combined into a uniform database. Information
on each photo includes time and location, image quality, amount of marks
on whales, and lengths of whales. NMML also provided data from aerial
transects flown in support of the ice-based censuses conducted in the Barrow
area. (These censuses were under NMML direction until 1982 but are now
done by the North Slope Borough). Most of these data files were compiled
by Dr. Judy Zeh at the University of Washington prior to delivery to the
IWC. Data from other laboratories include acoustic locations of whales
during census periods, harvest records, corpora rates, pregnancy information,
aging indicators relative to baleen growth and lens racemization, and genetics.
By Dave Rugh.
Joint Russia-Canada-US Project to Tag Belugas off the Chukotka Peninsula
In November and early December 2003, Rod Hobbs (NMML), Greg OCorry-Crowe
(Southwest Fisheries Science Center (SWFSC)) and a Russian colleague, Dennis
Litovka (ChukoTINRO), traveled to Lavrentia Bay on the Chukotka Peninsula
in far eastern Russia. The trip was the first field season of a 3-year
joint Russia-Canada-U.S. project to collect genetic samples from and attach
satellite transmitters to beluga whales that spend a few weeks each fall
in Lavrentia Bay. The genetic samples will provide information on the
stock identity of the whales and may indicate that these whales spend time
in U.S. or Canadian waters. The biopsy samples will be collected either
directly while handling the belugas to attach transmitters or remotely
by using a crossbow and biopsy dart. The satellite transmitters will collect
dive information and transmit these data to an ARGOS receiver on a satellite.
The location of the whales will then be calculated from the location of
the satellite and the Doppler shift in the radio signal. The location
and dive data from the satellite tags will provide information on the movements
and behavior of the belugas as they (presumably) overwinter in the Bering
Sea and, possibly, during their spring and early summer migration.
The field team spent a productive field season scouting capture locations
and developing contacts with local Chukchi, Inuit, and Russian marine mammal
hunters to get biopsy samples from harvested belugas. However, the belugas
did not arrive at Lavrentia Bay during the field season. Local knowledge
indicates that the belugas typically move south into the Bering Sea with
the sea ice, and sea-ice formation was unusually late this fall. Although
Lavrentia Bay had frozen over by the end of the field season, sea ice had
not formed offshore from the bay. However, a local hunter sighted belugas
near the field location 4 days after the field team departed, and he collected
biopsy samples from whales harvested in the area. These samples will be
sent to the genetics lab at the SWFSC for analysis.
By Rod Hobbs.
Workshop on Odontocete Capture and Handling Techniques
A workshop, entitled Capture and Handling Techniques for Small Odontocetes
During Tagging, Health Assessment, and Sample Collection, was convened
in mid-December at the 15th Biennial Conference on the Biology of Marine
Mammals, in Greensboro, North Carolina, by Rod Hobbs (NMML), Stephanie
Norman (NMFS Northwest Region), Jonas Teilmann (Denmark), Tony Martin (UK),
and Brad Hanson (NWFSC), with funding from NMML. The workshop provided
a forum for the exchange of ideas between researchers, veterinarians, and
other interested parties on handling and attachment practices during tagging
and other capture activities. The capture-release of odontocetes for tag
deployment, as well as for clinical assessments and tissue collection,
has become an important component of studies of behavior, range, habitat
use, and the health and reproductive status of free-ranging animals. The
workshop emphasized techniques and issues related to animal and human safety
that are common to studies of several species.
The workshop opened with a series of oral presentations along with poster
sessions during the breaks. This was then followed by a group discussion
which focused on specific issues raised during the talks. The workshop
was attended by more than 60 people, ranging from students to scientists
with many years of experience in handling cetaceans. The talks included
specific examples of capture and handling techniques for a variety of species
and circumstances, as well as issues concerning the successful handling
and health and well being of the animals and their handlers, such as monitoring
animals during handling, tag-release mechanisms, and zoonotic diseases.
By Rod Hobbs.
Abundance of Cook Inlet Belugas
Figure 1. Estimated abundance of Cook Inlet beluga whales for the years 1994 through 2003.
NMML scientists have completed an abundance estimate for the Cook Inlet
beluga population from observer counts and video data collected during
an aerial survey of Cook Inlet in early June 2003. During the survey, the
complete coastline of the inlet and several transects of offshore waters
were surveyed (see July-September 2003 Quarterly Report for additional
details). Aerial video of beluga groups was analyzed and compared to observer
counts to estimate group sizes, which were summed to estimate the population
abundance. We estimated that there are 357 whales in the population. This
estimate has a CV of 10.7%, yielding a 95% confidence interval of between
289 and 440 belugas and an Nmin, for management purposes, of 326 belugas
(Fig. 1 above). This abundance estimate falls within the range of estimates over
the previous 5 years, which suggests that there is no significant increasing
or decreasing trend.
By Rod Hobbs.
quarterly Oct-Dec 2003 sidebar
Auke Bay Lab