5.1         International Whaling Commission Cetacean Sighting and Biopsy Summary

(D. Thiele)

 

Visual survey was conducted throughout the cruise in suitable weather conditions and commenced off the east coast of Chile on the southward journey to the Western Antarctic Peninsula study area. Few sightings were made until reaching the Boyd Strait and Gerlache Strait area on 10 February. Humpback whales were numerous in this area (28 sightings/59 animals). Throughout the first mooring deployment phase of the cruise (1118 February), small numbers of humpback, sei, minke, killer and unidentified whale sightings were made. After weather conditions deteriorated at B2 mooring site on 19 February, the ship headed for Pourquoi Pas to conduct cetacean survey in calmer waters until weather cleared in Marguerite Bay. Weather conditions were not good, and only small numbers of humpback and minkes were sighted. Mooring deployments commenced in Marguerite Bay the evening of 21 February.

 

Cetacean survey continued on the afternoon of 22 February on a track to the ice edge. Humpback whales were concentrated near the ice edge (10 sightings/30 animals) at the southern end of Marguerite Bay. Two biopsy trips were made using the Zodiac, resulting in five biopsies (skin and blubber) from two groups. Plans to continue survey along this ice edge to the east were cancelled due to worsening weather the next morning.

 

The ship again headed for the protected east coast of Adelaide Island and Matha Strait. Matha Strait was reached on the morning of 24 February. The ice edge here extended out into the mouth of the Straits, precluding survey. A large number of seals were evident here throughout the sea ice. The ship headed further north to Pendleton Straits and cetacean survey was conducted throughout this area. Humpback whales were concentrated in the Pendleton Strait/Mudge Passage area. Single minke whales were also sighted throughout the passage.

 

Palmer Station was reached on 26 February. Two pairs of humpbacks were sighted off Cormorant Island by Palmer Station personnel and a zodiac trip to obtain biopsies resulted in two samples from one pair and individual photo-identification records for all four animals. Humpback whales were also numerous during the transit through Dallman Bay on 27 February (20 sightings/42 animals). Calm conditions across the Drake Passage on 28 February provided good sightings of three groups of Mesoplodon, hourglass dolphins and a sperm whale.

 

The total time on effort up to 28 February was 148 hours 40 minutes.

 

Cumulative species

Cumulative

sightings/animals

Unidentified large whale

7/10

Hourglass dolphin

2/14

Humpback

75/168

Undetermined minke

13/18

Unidentified whale

11/62

Killer whale

1/25

Sei

1/8

Unidentified small whale

1/2

Unidentified cetacean

2/3

Like minke

2/2

Mesoplodont

3/13

Sperm whale

1/1

Cumulative TOTAL

117/322

 

Summary of cetacean sightings during LMG02-1A (to end 28 February)