IWC SO GLOBEC COLLABORATION

US SO GLOBEC CRUISE LMG 03-02 MOORING CRUISE

12 February - 7 March 2003

Report 1 dated 25 February

The L.M. Gould departed Punta Arenas on 12 February heading for Palmer Station and the mooring recovery area around and to the north of Marguerite Bay. The cruise objectives included the recovery of 3 WHOI oceanographic moorings and 7 Scripps baleen whale passive acoustic moorings (ARP's - acoustic recording packages) which have been down recording baleen whale calls since February 2002; cetacean visual survey, photo identification and biopsy; and the redeployment of one of the ARP's to ensure continued temporal coverage of baleen whale presence in the northern Western Antarctic Peninsula.

During marine mammal survey time we will explore the ice edge and other parts of the study area where concentrations of whales have occurred during the two years of SO GLOBEC summer/autumn/winter sampling. The priority areas are: the ice edge; Matha Strait/Crystal Sound; Laubeuf Fjord; other fjords behind Adelaide Island. In addition we hope to find blue whales by deploying sonobuoys and looking at recent ARP data; using this information to locate at least one animal to obtain photo identification, biopsy and acoustic data simultaneously.

While retrieving ARP S2 (which we chased as the Antarctic Circumpolar Current carried it away from us at high speed!) we found sei whales. At least three separate groups could be seen in the area all surface active (we observed side lunge feeding at the surface). A sonobuoy was deployed to collect any calls this usually quiet species might make. At the same time, visual observations and photographic data were collected (pic 1. sei whale). The sei whales were surprisingly vocal, and high quality recordings were made of a variety of calls (pic 2. sei whale sonogram).

Humpback song was recorded on the 21st in Marguerite Bay.

During the late afternoon of Saturday 22nd Feb, as we steamed around the edge of the shoals surrounding Faure Islands on the way to ARP S9 we encountered a group of three socialising humpbacks. The adult and two juveniles had been sighted some miles previously - breaching and active at the surface. The two younger animals continued to breach, often together as the ship steamed slowly by (pic 3. breaching humpback). Then all three approached the ship to within 20 m, coming close enough for everyone on board to watch.

ARP S9 was retrieved and examined for whale calls. Initial analysis of the recordings reveal a seasonally distinct pattern of humpback (spring summer autumn) and minke (autumn winter) whales presence linked to the expansion and retreat of sea ice cover.

Monday 24th February was spent surveying the ice edge and marginal ice edge zone (MIEZ) in the far south of Marguerite Bay by the northern tip of Alexander Island. Many humpback whales and some minke whales were sighted here. Teams were deployed in the Zodiac throughout the day to gather photo identification records and tissue biopsy samples. Biopsy samples were obtained for three humpback and one minke whale. Although no large concentrations of whales were encountered, we observed humpbacks, killer whales and minkes. Small concentrations of whales tended to be fairly widely spaced along the MIEZ. The waters in this zone were thick and soupy with algae, and many whales were observed feeding.

Today we will spend the day dragging for a WHOI mooring in the northern end of Marguerite Bay and then head to the Laubeuf Fjord, Tickle Pass and Matha Strait to investigate the other areas where densities of whales were high in previous summer, autumn and winter cruises.