Biology & Medicine

Dr. Polly Penhale
Program Manager

B-289-M

NSF/OPP Award 03-38428
Station: McMurdo Station
RPSC POC: Karl Newyear
Research Site(s): McMurdo Station, USCG Icebreaker
Dates in Antarctica: Early December to early February

Genetic and photogrammetric investigations of three ecotypes of Killer whales in the southern Ross Sea
Dr. Robert L. Pitman
National Oceanic and Atmospheric Administration
Protected Resources Division
Robert.Pitman@noaa.gov
[No website]
Mother-calf pair of "Type C" killer whales in the Ross Sea. Type C killer whales are smaller and occur in larger groups than killer whales found throughout the rest of the world. They prefer fast ice, are known to eat fish, including Antarctic toothfish, and may be a separate species. Photo by Robert Pitman.
Deploying Team Members: Don LeRoi . Wayne Lloyd Perryman . Robert L. Pitman
Research Objectives: Commercial whalers were the first to realize there may be more than one species of killer whales in Antarctica. Large killer whales live outside the pack ice and feed on Minke whales. Smaller ones are lesser known because they live in the pack ice, where they eat mawsoni and other fish. They are about 20 to 23 feet (6-7 m) long, which is 3 to 5 feet (1-1.5 m) shorter than the regular killer whale. And there may be yet a third species; a distinctive eye patch and differing school size may further distinguish the smaller killer whales into two groups, which don't intermingle. This project’s goal is to determine if the types of whale are indeed distinct species.

Three observers aboard the USCG icebreaker will stand watches on the bridge during the transit from Hobart to McMurdo Station. When a killer whale group is sighted, and depending upon the circumstances (killer whale type, weather, time of day, operational conditions, ship’s schedule) a request may be made to deploy a launch, a helicopter, or both. The data will be particularly valuable if both launch and helicopter operations can be used on the same group of killer whales.

Team members will collect biopsy samples using small boat operations and a projectile biopsy system developed and used successfully over the last 15 years. The fired dart has a hollow tip that extracts a tissue sample, bounces off the animal and is retrieved with a scoop net. The samples will be sequenced and analyzed at the Genetics Laboratory of Southwest Fisheries Science Center in La Jolla, California to compare genetic divergence among the three forms of killer whales.

Researchers will also obtain aerial photographs of individual whales using a helicopter-mounted 35-mm camera system. When the camera is fired, an altitude is automatically recorded from the radar altimeter and a position recorded from the GPS. These photographs will be used to accurately determine lengths and body proportions for morphological comparisons among the three forms. Previously published information indicates that the form that is most common in the southern Ross Sea may be significantly smaller than “regular” killer whales. Body length and body proportion data from aerial photographs can provide crucial morphological evidence for phenotypic divergence and speciation within this group.