LM GOULD Cruise 05-01 Palmer LTER January Cruise 2005 Situation Report 4 21-30 January 2005 In the final week of the cruise we completed the remaining line of stations in the LTER Grid (the 200 line south of Adelaide Island) and also successfully occupied and completed the 300.040 and 400.040 stations that were both in sea ice and were postponed earlier. Once again we occupied all LTER Grid stations. This is always the top-priority goal of the annual January cruise. Missing stations due to lack of ship time, bad weather or technical failures compromises our long-term sampling program. They can never be recovered. This year we also managed to occupy four "negative" 200 stations inside Marguerite Bay. We observed very high plankton biomass and oxygen concentrations and low pCO2 and nutrients at the -040, -020, 00 and +020 sites, indicating a large phytoplankton bloom in the Marguerite Bay area. After deploying the seabird ecology team to Avian Island, we visited the BAS Base at Rothera Station. This is an annual feature of our cruise. Our BAS colleagues (and LTER PI Andrew Clarke) are coordinating time-series observations in Ryder Bay with the LTER. They came out and spent a day aboard LMG, cross-calibrating instruments with ours, talking science and planning several cooperative experiments. Several social events (stations tours, hiking, a soccer game, dinner, a rock band and dance) rounded out our visit. We lost 2-0 in a hard fought soccer match but vow our revenge next year. On Avian Island, the birders placed foraging tags on 4 penguins. These small satellite transmitters report the positions of the penguins while they are on the surface foraging. We used the positions to locate a 24-hr process station near Adelaide Island at -67 35; -69 31. We attempted to do this exercise in real-time oceanography at Renaud island at the beginning of the cruise, but were stopped by heavy sea ice. In essence, we use the penguins to tell us where to locate our stations, then make measurements over 24 hr in that area. The goal is to gain a better in-depth understanding of ecological processes in the regions where the three principal penguin rookeries are located along the Peninsula. The birders were recovered successfully (see report below). The third process station was beset by difficulty. Although much of the nearby area exhibited very high biomass (see above), plankton levels were lower at the chosen site. Krill were largely absent. One possible explanation is that large krill swarms (as observed nearby) attracted penguins from the large Avian Island colony (100,000 breeding pairs) to this area and also cleared the area of diatoms. Then the Adelies came in and ate the krill just before we arrived. We hope to repeat this experiment next yea at 2 or 3 sites. Later in the day, high winds prevented the final krill survey and we returned to Avian Island to pick up the birders. On this year's cruise we collaborated with Bob Beardsley and Dick Limeburner (WHOI) and deployed Lagrangian current drifters along the LTER Grid. These drifters move with the surface currents (upper 20 meters) and report their positions by satellite. Although several drifter sets were released during the Austral winter during Southern Ocean GLOBEC, there were no data for the summer period until now. The early returns suggest a south-flowing coastal current, cross-shelf transport and energetic currents off the shelf edge. Heavy sea ice continued to hold our attention during the final days of the cruise. Pack ice in 8 to 10/10 concentration extended to 200.090 on our grid. Southerly winds moved the pack north, uncovering 300.040 but we again encountered heavy pack ice between the 300 and 400 lines. Station 400.040 was in 8 to 10/10 cover. We planned to occupy our "inside" stations (stations between the offshore islands and the coast proper) at 380.010, 440.010, 550.000 and 585.010 but heavy sea ice slowed our transit to these locations. A partial station was completed at 550.000. Occupying the inside stations, and the opportunity to tag penguins at Renaud were the only cruise objectives we didn't meet. A research cruise is a large, long and complex endeavor and it's success or failure depends on luck, dedication and skill. We were very lucky this year. The weather was good, the skies clear and the seas calm. Sea ice prevented some operations but gave us a rare opportunity to observe our study site in a unique, even extreme state. Most of all, though, we profited from the hard work, experience and skills of ECO Captain Scott Flanagan and his officers and crew; and the RPSC technical group headed by MPC Andy Nunn. Last but hardly least, we rely on students and volunteers to help accomplish the many scientific objectives of our cruise. Thanks to them all for a wonderful cruise. It's been a pleasure to bring you these weekly reports. We especially appreciate he feedback and comments on them that you send. It helps a lot, especially when we have to take time at the end of 12 to 16 hour shifts to compose them for you. Detailed reports follow. Hugh Ducklow B-045 and Chief Sci. B-013-L PAL LTER Seabird Ecology Principal Investigator: Bill Fraser Field Team: Peter Horne and Brett Pickering During the past week our group monitored sea bird abundances along the 400 and 300 lines of the LTER Cruise grid. Sea bird and marine mammal numbers were monitored by counting all individuals encountered while moving between stations. Once a station was reached a stationary census was conducted. On the 21st of the month ice conditions finally were cooperative, as the LMG was able to make it into the northern side of Marguerite Bay and the near vicinity of Avian Island as scheduled. We were able to set up a field camp on Avian's north side. By 9:30 am on the 21st we had set up camp and were ready to start working. Our goals during the five day field camp were to monitor Adelie penguins in selected colonies, deploy satellite transmitters and time depth recorders, perform diet sampling and map the penguin colonies using GPS. During our time on Avian the weather was mostly wet, but did not hinder our work. We were able to map all the penguin colonies over the course of three days, which will allow us to make estimates of the size of the Adelie breeding population. After being recovered from Avian on the 26th we continued bird observations on the 200 line and two inside stations during the transit back north to Palmer Station. We would like to thank the RPSC staff, the bridge crew and cooks aboard the LMG for the assistance during the cruise. B-016-L PAL LTER Phytoplankton Ecology Principal Investigator: Maria Vernet Field Team: Karie Sines, Eli Loomis, Austen Thomas, Jessica Spence The goal of our project is to characterize the ecology of phytoplankton including daily primary production rates and photosynthetic pigments in relation to environmental parameters. During the third week on the cruise we sampled a 4th transect and we are in the middle of the 5th transect, performed 3 microzooplankton grazing experiments and obtained 15 successful Profiling Reflectance Radiometer casts. Ice is present in the coastal stations towards the middle of the Southern transect line. We thank personnel on the ARV LMG Gould, Palmer Station and Punta Arenas for logistical support of this project. B-028-L PAL LTER Zooplankton and Micronekton Principal Investigators: Robin Ross (on LMG) and Langdon Quetin (at Palmer Station) Field Team: Lyndon Valicenti, Gregory Quetin, Kelly Moore, Stephen Holloway, Katie Davis, Diane Chakos With only a few days left in the cruise, we have completed our simultaneous net tows and acoustic transects at all but the far inside stations that are covered by ice. The length frequency distribution of Antarctic krill is dominated by the year classes of 2001 and 2002, now 35 - 50 mm long. The digestive glands of the krill at most of our stations have been dark green, indicating heavy feeding on phytoplankton. At Process Station 1 near Palmer Deep and Process Station 3 in the mouth of Marguerite Bay, we conducted fecal pellet production experiments with Antarctic krill, and extracted phytoplankton pigments from both krill and salps for estimation of a grazing index on phytoplankton. At Process Station 3 we also launched a trawling zodiac to process Antarctic krill for these indices of grazing within a few minutes of collection. At this juncture it is clear that the reproductive cycle for Antarctic krill this year was delayed by almost a month across the entire study region, not just in the north. The vast majority of the female krill found have been in the initial stages of the reproductive cycle, and only in the far south of the grid (the 200 line) have we found gravid females ready to release eggs. The near total absence of the shelled pteropod Limacina and the presence of ice krill (Euphausia crystallorophias) out onto the middle shelf are additional evidence that this is an abnormal year. We would like to particularly thank MTs Pete Dal Ferro and Jamee Johnson for their assistance as we towed in the ice-covered waters of the inner 200 line, and MT Pete Dal Ferro and Fred Stuart for joining team 2 during the zodiac trawling of Process Station 3. B-045-L PAL LTER Microbial Ecology and Biogeochemistry Principal Investigator: Hugh Ducklow Field Team: Nicole Middaugh, Elizabeth Waterson, Kristin France, Robert Daniels, William Ducklow Our team continued to make measurements of microbial processes and biogeochemical processes during the final 10 days. There was very high bacterial activity at the inner stations along the 200 line -- as much as an order of magnitude greater than elsewhere on the grid. Oxygen concentrations were very high in the surface at these stations, and notably low in the deeper waters. Both extremes suggest very high biological activity associated with the phytoplankton bloom in Marguerite Bay. On this year's cruise we obtained replicate samples for pCO2 (the partial pressure of carbon dioxide, an index of biological activity and air-sea gas exchange) at all grid stations, process stations and one inside station. Vertical pCO2 profiles were obtained at 3 stations as well. The cruise was very productive with over 500 samples collected for bacterial processes, DOC, pCO2, and oxygen. We thank Captain Flanagan and the LMG crew for another successful cruise, and Andy Nunn and his team for all their help: MTs Pete Dalferro and Jamee Johnson for staging and recovering the CTD rosette on which all our sampling depends, ETs Fred Stuart and Mike arpener for operating the CTD and firing bottles, and MST Jeff Morin for keeping our lab running with his support. B-114 PAL LTER Microbial Ecology and Molecular Microbial Ecology Principal Investigator: James T. Hollibaugh Field Team: Matthew Erickson and Gary LeCleir The primary objectives of bacterial cell collection for DNA analysis and ammonium and nitrite rate experiments of Project B-114 have been met during the LMG 05-01 cruise. Our project collected water at 25 stations within the LTER grid for investigating microbial assemblage of the water column. Large volumes of water (>100L) were concentrated using tangential flow filtration and centrifugation, for the purpose of constructing large insert DNA fosmid libraries. These libraries will facilitate the investigation of genes required in the nitrification process. The project conducted experiments at 15 different stations encompassing the LTER grid. Depths at these stations were chosen based on nutrient data provided by on board nutrient analysis. The nutrient profiles were used to focus water collection on the ammonium and nitrite maximum. A sub surface depth (10-20m) and a deep depth (60-100m) were chosen when nutrient data was not available at the time of the cast. Water column studies of ammonium oxidations showed very low rates. Size fractionation experiments were conducted at three process stations to determine the microbial size fraction responsible for nitrification. We conducted an additional size fractionation experiment on ice slush collected near shore. We would like to thank the Palmer-LTER group for their scientific support. The project would also like to give thanks to the crew of the LMG and Raytheon employees for the tireless 24 hour service to provide logistical support. ---------------------------------------------------------- Hugh Ducklow Aboard the research vessel LM GOULD Palmer LTER Cruise Jan05