Weekly Science Report 1: LMG02-05 Southern Ocean GLOBEC

Cruise days 29 July to 4 August inclusive

Science days 30 July to 4 August inclusive


I.  LMG 02-05


a.  Mission statement: The U.S. Southern Ocean Global Ocean Ecosystems Dynamics (U.S. SO GLOBEC) Program is in its second and final field year. The focus of this study is on the biology and physics of a region of the continental shelf to the west of the Antarctic Peninsula that extends from the northern tip of Adelaide Island to the southern portion of Alexander Island and includes Marguerite Bay. The overall goal is to elucidate shelf circulation processes and their effect on sea ice formation and Antarctic krill distribution, and to examine the factors that govern krill survivorship and availability to higher trophic levels, including seals, penguins, and whales.


This is the second of two joint cruises. The first occurred in April-May and this, the second cruise that is occurring from 29 July – 19 September 2002 onboard the RVIB N.B. Palmer, which is carrying out a broad scale survey, and the ARSV L.M. Gould, is conducting process-oriented studies. The goal of the process cruise aboard the ARSV L.M. Gould is to provide a more detailed examination of the biological and physical processes that are occurring in this region that can be put into the shelf-wide context supplied by the broad scale survey being carried out at the same time on the RVIB N.B. Palmer.


b. Projects represented on the process cruise


BG-232-0 Costa/Burns/Crocker:  Foraging Ecology of Crabeater seals

BG-234-0 Fraser:  Winter Foraging Ecology of Adélie Penguins

BG-235-0 Fritsen:  Sea Ice Microbial Communities

OG-241-0 Smith/Martinson/Perovich: Optical Environment of the Western Antarctic Peninsula Region

BG-244-0 Quetin/Ross: Winter Ecology of Larval Krill: Quantifying their interaction with the Pack Ice habitat


c.  Cruise overview to date


29 July

Given that the arrival of a number of key pieces of equipment (SCUBA tanks, baggage, snowshoes) the departure of the L.M. Gould was delayed until 18:00.  With Pilot aboard, the L.M. Gould departed Punta Arenas 53º 10.164′ 70º 54.999′ just after 18:00 local time (LT) on 29 July 2002 to begin the U.S. SO GLOBEC Process IV cruise. The skies were overcast but winds were light.  Shortly after leaving port, we had our first ship orientation and safety meeting with 3nd Mate Alan Arrigoni and MPC Karl Newyear at 19:30. The goal of this meeting was to ensure that all on board were prepared for unexpected emergencies.  This included getting into our survival suits, getting into the lifeboats and a general review of ships safety and procedures.


30 July

The second day we steamed along the eastern coast of Argentina and cleared the Strait of La Maire and the entrance to the Drake Passage around 23:00. At 10:00 MST Mo Hodgins carried out a chemical safety meeting in the Hydrolab. We had our first fire drill at 12:30 today, with an excellent response, with all members of the scientific party having responded within 3 minutes. Once in the lounge 2nd Mate Jay Bouzigard and MPC Karl Newyear discussed fire safety issues. Later this evening (19:30) we had a scientific orientation led by Daniel Costa, where the general goals of the program were discussed including the specific logistics that will be required during the cruise. The weather was overcast and cool visibility was limited.  We exited the sheltered waters of the Straits of Magellan and the east coast of Tierra del Fuego, and encountered significantly more ship motion than previously experienced in the sheltered waters of the straits or in the lee of Tierra del Fuego. As we entered the Drake the seas picked up slightly and the ship increased its roll.  However, the ride was not bad and the seas were better than we had expected. Once we reached the Drake Passage an XBT survey was initiated starting at 22:35 LT (54º 56.1′ 64º 57.4′).  This survey is being carried out for Dr. Janet Sprintall of the Scripps Institution of Oceanography (OO-260) who is interested in the dynamics of the Polar Front. XBTs were launched approximately every 10 minutes of latitude during the crossing.  Our regular schedule of radio communications was initiated with Palmer Station today at 13:00. Our first iceberg was sighted near 57º 20′S. We expect to see pack ice within the next 24 hours or so.


31 July

The L.M. Gould (LMG) continued across the Drake Passage towards Palmer Station via the inside passage route. We continued the XBT transect across the Drake.  The LMG stood by for one hour to adjust ballast. Over the course of the evening 1 Georgian Diving Petrel and 3 Kerguelean Petrels were found to have landed on the bridge.  It is common for petrels to be attracted to the ships lights and crash into the bridge. After id we moved these birds to afterdeck where they could more easily fly. Our first XCTD was released at 05:46 LT (56º 1′ 64º 38.9′). During the evening MTs Jenny White and Sparky Weisblatt deployed one of two NOAA Technoccean global drifters at 59º 02.3′ 63º 40.1′. One of the MTs received an injury to a finger while deploying a buoy. We anticipate arrival at Palmer Station on the morning of 3 August.


1 August

The L.M. Gould continued across the Drake Passage, which treated us reasonably well, though with a fair bit of rolling due to beam seas. Andy Nunn and Shonna Dovel with Karl Newyear supervising deployed the second NOAA Technoccean global drifter. MST Mo Hodgins carried out a Radiation Safety briefing with the two programs that will be using rads at 18:30. Ice observations were initiated at 03:00 and will continue until we leave ice. Ice (shuga and grease) was first observed at 03:05 and 8/10 pancake and brash ice was observed at 03:15 at 59º 49.9′S 63º 25.2′W.


2 August

The LMG passed between Smith and Snow Islands at the end of the "central" route across the Drake Passage. This crossing took a few hours longer than normal due to unusual amounts of ice as far north at 60ºS. Penguins were observed on a floe at 11:00.  Preparations were made to capture the birds for stomach sampling, but they retreated to the water before we could put a Zodiac in the water.  We finished the XBT transect for Janet Sprintall this morning at 08:06 local time (12:06 GMT) at 62º 42′. As we passed through the pack ice we have seen a many sub-adult and adult male Antarctic fur seals.


We saw a large group (10-20 individuals) that porpoise off together at 15:10 (64º 34′S 61º 26.7′W).  Later on we saw our first leopard seal of the trip at 63º 43.1′S 61º 20.26′W.  Much of the day has been spent preparing for our stop at Palmer Station. We plan on arriving tomorrow morning around 08:00, conducting cargo operations, and spending the night before heading toward Crystal Sound on Sunday morning.


3 August

We arrived at Palmer Station at 08:43 LT. Cargo offload began shortly thereafter and continued well into the afternoon.  There was very little science preparation to do as the Bio Lab was being renovated.  Almost all preparations (sample weighing, etc.) had taken place in Punta Arena prior to departure. Many individuals enjoyed the walk up the glacier behind Palmer Station. Quetin's group took advantage of open water in the channel next to the ship to carry out a series of practice SCUBA dives.  In the early afternoon the ice opened up so that the seabird group attempted a tour of Palmer Sound to look for Penguins and Seals. However, they were only able to get as far as Christine Island before the wind changed forcing them to return, as the pack ice was moving back towards Palmer Station. Many of the ship's party enriched the coffers of the Palmer Store, purchasing souvenirs and other items.  Palmer Station extended their hospitality with an all-hands pizza feed that started at 18:00.  The pizza was excellent, as was the party that followed.  It was a nice diversion as we prepare for the intense period of science that awaits us.


4 August

The L.M. Gould departed Palmer Station at 10:00 and began steaming towards the SO GLOBEC Matha Strait and Crystal Sound to initiate the predator studies. We had open water for the first few hours and at 14:00 hours we carried out a full CTD cast at 65º 06.045′S 65º 08.06′W to test the rigging and electronics.  This location also coincided with the first appearance of a significant ice edge since departing Palmer Station.  As we went south offshore of the Biscoe Islands we sighted a Weddell seal, a Gentoo Penguin and a crabeater seal were observed on a workable ice floe at 65º 11′S 65º 23.7′W.  We attempted to get into position to work with the seal, but it went into the water. We are currently proceeding to Pendleton Strait where we should arrive by morning. We will proceed along the eastern side of Lavoisier Island to continue looking for Adélie penguins and crabeater seals en route to Matha Strait where we will rendezvous with the NBP sometime tomorrow.