National Marine Mammal Laboratory (NMML) (cont.)

CETACEAN ASSESSMENT AND ECOLOGY PROGRAM:
International Whaling Commission Scientific Committee Meeting

Sue Moore (NMML Director), Paul Wade (Cetacean Assessment and Ecology Program Leader), and reserach biologist Nancy Friday attended the International Whaling Commission (IWC) Scientific Committee Meeting, 26 May - 6 June 2003, in Berlin, Germany, prior to the 55^th Annual Meeting of the IWC.


Cook Inlet Beluga Survey

Sightings of beluga whales in Cook Inlet, Alaska, during the standard aerial surveys conducted in June 2003. Sighting locations are typical for this time of year as evidenced by similar surveys conducted over the past decade.  (click image to enlarge.)

NMML biologists and the NMFS Alaska Regional Office, Anchorage, conducted an aerial survey of the beluga population (Delphinapterus leucas) in Cook Inlet, Alaska, from 31 May to 12 June 2003. The 61-hour survey was flown in a twin-engine, high-wing aircraft (an Aero Commander) at an altitude of 244 m (800 ft) and a speed of 185 km/hr (100 kt), consistent with previous NMFS surveys conducted in Cook Inlet each year since 1993. The flights included one or more surveys of coastal areas (flown 1.4 km offshore) around the entire inlet and 1,145 km of transects across the inlet, effectively searching 25% of all the surface area of Cook Inlet but covering 100% of the coastal areas. Paired, independent observers searched on the left (coastal) side of the plane, where virtually all beluga sightings occur, while a single observer was on the right. A computer operator/data recorder was also on the left side. After finding beluga groups, two pairs of observers each made four or more independent counts of each group during a series of aerial passes. In optimal viewing conditions on six different days, the median counts were 0-41 belugas in the Susitna Delta (between the Beluga and Little Susitna Rivers), 30-94 in Knik Arm (there appeared to be exchanges of whales between the Susitna area and Knik Arm), and 21-65 in Chickaloon Bay (including the western end of Turnagain Arm). No belugas were seen elsewhere. This sighting distribution has been consistent in June or July most years since 1996. The sum of the median aerial estimates (a very rough but quick index of relative abundance, not corrected for estimates of missed whales) for June 2003 is 174 belugas. This is below index counts for years prior to 1998 (305 in 1993, 281 in 1994, 324 in 1995, 307 in 1996, and 264 in 1997), but it is essentially the same as counts during the past 4 years (193 in 1998, 217 in 1999, 184 in 2000, 211 in 2001, and 192 in 2002).

By Dave Rugh.


Bowhead Whale Photography

An adult bowhead whale with its newborn calf during the spring migration past Barrow, Alaska. (Photo by Dave Rugh.)

As part of NMFS management of the western Arctic stock of bowhead whales (Balaena mysticetus), surveys were conducted 11 April to 6 June 2003 near Barrow, Alaska, to collect aerial photographs throughout the stock's spring migration into the Beaufort Sea. Most of the funding for this study was provided through a grant to the North Slope Borough (NSB), supplemented by support from the NMML. Support included participation by John Brandon (under contract through NMML's Cetacean Assessment and Ecology Program) for the entire season and by Sue Moore (NMML Director) for 1 week. The project is a continuation of photographic surveys conducted by NMML between 1985 and 1992.

The 2003 survey was carried out in an Aero Commander, a twin-engine, high-wing aircraft, generally flown at altitudes of 130-170 m (400-500 ft) and a speed of 185 km/hr (100 kt). Surveys were flown almost every day, for a total of 174 hours in 55 days, with very little time lost due to weather. The nonsystematic search effort was conducted along open water areas north and east of Point Barrow, avoiding whaling camps to the west. After finding bowheads, a series of aerial passes was made to obtain vertical photographs through a port in the floor of the aircraft. A hand-held, medium format camera was used to collect 1,150 photographs. The whale images will be studied to identify individual animals.

Reidentification of animals between years will help answer questions about abundance, survival rates, and calving intervals.

A similar survey, following the same protocol used in 2003, is planned for spring 2004. The objective is to provide the "recapture" portion of the "mark-recapture" study, where "marks" refer to animals with identifiable markings on the dorsal surface. All survey activities are conducted in cooperation with the NMFS Alaska Regional Office, the Alaska Eskimo Whaling Commission, and the NSB.

By Dave Rugh.


False Pass Killer Whale Survey

In collaboration with the North Gulf Oceanic Society (NGOS), the NMML participated in a killer whale survey mid-May through early June 2003 on a 42-ft fishing vessel, the Lucky Dove. Research effort focused on locating transient (mammal-eating) killer whales in and around the False Pass area between the Alaska Peninsula and the Aleutian Islands.

Photo-identification, biopsy, acoustic recording, and prey-sample data collected during the survey will be used to determine abundance, distribution, stock structure, ecology, eco-type and what, if any, impact killer whale predation has on the declining western stock of Steller sea lions. These data provide some new baseline information about killer whales in the Alaska Peninsula/Aleutian Island area and are a valuable addition to what is currently known about killer whales off Alaska, British Columbia, and the west coast of the United States.

By Lori Mazzuca.


POLAR ECOSYSTEMS PROGRAM:
Harbor Seal Abundance and Distribution in Cook Inlet

Aerial photograph of harbor seals during pupping, Kamishak Bay, Cook Inlet, Alaska. (Photo by John Jansen.)

The NMML Polar Ecosystems Program has begun a two-part study of harbor seals in Cook Inlet under an Interagency Agreement between the Department of the Interior's Minerals Management Service (MMS) and NMFS. The first part of the study focuses on estimating seal abundance and mapping the distribution of haul-out sites over a complete annual cycle with an emphasis on two, key life history events: pupping (June) and molting (August). The second part of the study focuses on identifying the factors that affect seal haul-out behavior at different sites in Cook Inlet and to quantify the relationship between these factors and haul-out patterns. These studies are needed by the MMS to support environmental risk assessments, environmental impact statements, and other documents pertaining to potential gas and oil development in the Cook Inlet planning area. The studies will also benefit NMFS in support of stock assessments and recovery of protected species.

To estimate harbor seal abundance and distribution, the first of six planned surveys was conducted 11-19 June 2003 to coincide with pupping. The survey area covered the east and west coastlines of Cook Inlet, stretching from the Barren Islands in the south to the East and West Forelands north of Kalgin Island. Surveys were flown over a 4-hour period centered at low tide, when the largest number of seals are expected to be hauled-out. The entire coastline was surveyed twice: at different tidal states (high-low and low-low) to increase coverage of potential haulouts, since some sites are not accessible at the lowest tides while others are usable only then. Coupled with this reconnaissance, site-to-site sampling yielded a total of 6-8 photo surveys at each haulout. Survey photographs are currently being counted. The next survey is scheduled for August 2003 to coincide with the seals' molting season.

To examine seal haul-out behavior, a remote camera system is being developed to count seals from images recorded at regular intervals under varying environmental conditions. In preparation for deployments, NMML researchers evaluated potential camera sites 14-25 June on Augustine Island, where two accessible and viewable beach haulouts totaling several hundred animals had been mapped previously.

Several camera sites were identified, and trails were cleared to allow better access. The researchers conducted hourly counts of seals to gain preliminary data on haul-out behavior and spatial organization of seals within the haul-out areas. Field deployment of the camera systems is planned to begin in October 2003.

By Peter Boveng, John Jansen, and Mike Simpkins.

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AFSC Quarterly
Research Reports
April - June 2003