Weekly Chief Scientist Reports

PD94-12 Chief Scientist Report for Week Ending 10 Dec 1994

After an approximately 5-day delay caused by inclement weather at King George Island (the C-130 aircraft supporting the SAAM I mission was unable to land due to dense ground fog), Project SANTA CLAµS (Studies in ANTarcticA: Coupled Linkages Among micro(µ)organisms) finally got underway from Palmer Station at 1330 hrs on 09 Dec 1994. This cruise is also designated PD94-12. Science personnel aboard include 12 from S-046 (Karl), 7 from S-002 (Mopper/Kieber), 2 from S-028 (Quetin/Ross) and 1 from S-201 (Amos). ASA staff support include R. Harelstad, D. Asselin and G. Smith.

An all hands science meeting was held at 1500 hrs to reassess our objectives in light of a loss of approximately 25% of our initially scheduled shiptime allocation. We adopted a revised schedule and by 1700 hrs were collecting our first water samples at LTER station 600.100. Unfortunately we experienced a mechanical problem with the winch that prevented us from bringing the rosette on board. The crew, including the Captain and Chief Engineer, were very responsive to our needs and personally expedited the repairs. This problem appears to have been solved.

During the brief 1-hr delay, R. Letelier (S-046) took the opportunity to make the maiden deployment of the tethered spectral radiance buoy (TSRB), a new instrument designed to provide measurements of the spectral characteristics of light at the sea surface. These data will provide information that will eventually be used to calibrate and interpret observations from the SeaWIFS ocean color satellite. This initial deployment was successful. After recovery of the rosette, two additional deployments were made to collect water for a series of shipboard experiments to investigate bacterial-algal-viral coupling processes.

At 0800 hrs on 10 Dec, we landed a 6-person field party on a small island in the Victor Hugo archipelago for the installation of a second LTER program automatic weather station (AWS). The first is deployed on Bonapart Point, near Palmer Station. Tony Amos and Langdon Quetin headed the group of ASA, S-046 and S-028 personnel. We would like to express our appreciation to Terry Johnson and Erick Chiang for expediting the preparation, review and approval of the Initial Environmental Evaluation (IEE) and Environmental Assessment (EA) documents; implementation clearance was received, by fax, at 1618 hrs on 09 Dec. Despite the cold, snow and rain the field party successfully installed the weather station and were back aboard the Polar Duke at approximately 1530 hrs. We immediately got underway for the LTER sediment study area, 30 nmiles to the northeast, to recover two bottom-moored sequencing sediment traps deployed during PD94-01 in January 1994. By 2130 hrs both trap arrays were safely aboard. One contained a rich time-series record of particle sedimentation for the past year; the second (replicate) trap failed to operate for reasons that were not immediately apparent. We conducted one CTD cast to collect water for algal growth experiments before steaming back to station 600.100 to commence sampling for project S-002 personnel. That sampling got underway just before midnight.

The R/V Polar Duke is fully packed with laboratory vans, specialized instrumentation and deck incubators. The underway data acquisition system is now fully operational and is recording weather (IMET package), navigation and position information, and surface ocean properties. The chief scientist would like to thank all ASA staff who assisted in cruise preparation, especially David Asselin and Glen Smith for their outstanding support. Weather has been generally calm but overcast, with favorable seas and open water.

PD94-12 Chief Scientist Report for Week Ending 17 Dec 1994

The past week has been very productive for scientists aboard the Polar Duke. There were no major equipment or logistical problems and we have continued to accomplish our stated cruise objectives.

We began the week at LTER Station 600.100 collecting water for various measurements and experiments. The Mopper-Kieber group deployed and recovered a 12-hr in situ photochemistry experiment, without incident. By the end of the day (12/11) we were underway for Crystal Sound to recover an experiment deployed in Jan 1994 and to begin our ice research. The last 20-25 miles was extremely difficult because of heavy pack ice (mostly 9/10ths) and poor visibility. We finally arrived on station at about 1300 hr and immediately established contact with the acoustic transponder. Unfortunately, the study area was completely covered by ice making recovery of the bottom moored array difficult to impossible. Our fallback position would be to recover the array during the Jan LTER cruise. We discussed the options and then decided to continue recovery ops. The Captain attempted to clear a "recovery area" by breaking up large floes. This was largely successful but the pack was already tight and could not be permanently cleared. On an impulse and with a prayer we released the array and hoped for the best. It was not to happen. The sediment trap was nowhere to be seen. By acoustic triangulation technique we eventually located the culprit floe and the bridge carefully honed it until the bright yellow floats of success emerged from the abyss. We lowered the MOB workboat to assist in recovery ops and by 2000 hrs the array and collected sample materials were safely aboard. It was a long, stressful but exciting day for science. My thanks go out to all who helped.

We then immediately began our water sampling and shipboard experimental programs. All CTD sensors, tethered spectral radiance buoy (TSRB) and profiling ultraviolet light (P-uv) meters worked flawlessly. On 12/13, we deployed another M-K in situ photochemistry experiment. As we prepared for our first scuba dive, the weather turned bad with sustained windspeed in excess of 30 kts. We went into a holding pattern. By 2300 hrs, the divers were in the water collecting the first of a set of ice algal community samples for shipboard experiments. We repeated the CTD, ocean optics measurements and shipboard experiments on 12/14. The divers also had the opportunity to collect a second set of ice algal samples. The passage of the low pressure zone over our study area had caused an already tight pack to become even tighter (mostly 10/10ths). Some new freezing was also evident. This made forward progress in the Polar Duke extremely difficult and slow. Between science ops we steamed north and by 12/15 we were in open water. We tucked back into the ice to collect a few additional samples before getting underway for points north.

On 12/16 we steamed back to the Victor Hugo mooring site at 64 29.8'S, 66 02.5'W and successfully redeployed the LTER long-term sediment trap array. It is now scheduled to be recovered in Jan 1996. A new dual acoustic release mechanism was incorporated into the design to further reduce the already low, but finite, probability of equipment failure.

We then landed a field party on SANTA CLAµS Island in the Victor Hugo archipelago to make final adjustments to the automatic weather station (AWS). We have already received reports from Wisconsin that last week's installation was successful and that the AWS was already sending excellent weather data. Our congratulations to Tony Amos and Langdon Quetin for a job well done. One final hydrostation was completed before we were underway for Hovgaard Island at the head of the Lemaire Channel. We had a most remarkable and pleasant passage and many rolls of film were consumed. We arrived back at Palmer Station in the early hours of 12/17 to return the S-028 personnel to their summer home and to collect a few items for science resupply.

By 1100 hrs we were in Paradise Harbor to begin the next phase of our expedition. The first hydrocast revealed that the spring bloom was in full swing with chl a values exceeding 15 mg per cubic meter. It was just what we had ordered! We immediately began our sampling and experiments, including the successful deployment of a short-term, time-series sediment trap that will be recovered just before we leave the study area, now scheduled for 0800 hrs on 12/22. An ambitious 5 days in Paradise is planned and we hope we can keep to our schedule.

PD94-12 Chief Scientist Report for Week Ending 24 Dec 1994

The past week has been a productive one for the phytoplankton in Paradise Harbor and for the scientists aboard the R/V Polar Duke. This phase of the SANTA CLAµS cruise was focused on a systematic and comprehensive study of the coastal phytoplankton bloom from gases and nutrients dissolved in the water to euphotic zone particle export rates. The intent of the intensive study was to determine the mechanisms controlling primary production and the rates and pathways of carbon and energy flow to higher trophic levels. Detailed experimental studies included analyses of phytoplankton, bacterioplankton, archaeoplankton, viroplankton and protozoa. Krill were studied, indirectly, by examination of fecal pellet fluxes. To track the progress of our experiments we held daily "all hands" science meetings at 1400 to review the most recent data and to plan experiments and sampling strategies for the next 24 hr period. The phytoplankton crop in Paradise Harbor was dominated by a small (5 um) cryptomonads containing large amounts of the water soluble pigment phycoerythrin. In addition to our suite of in situ and in vitro experiments, we continued to collect continuous underway data and CTD (profile) data at selected sites. There were no major equipment failures during this observation period.

On Dec 20 we conducted a mesoscale regional survey to ascertain the extent of this unusual and massive (> 15 mg chl a/m³) phytoplankton bloom. We took hydrostations and collected full profile water samples in Andvord Bay to the east and Gerlache Strait and Fournier Bay to the north. The same organism, at nearly the same concentrations, was found in all locations. We had also observed this organism at LTER sta. 600.100 and in the Lemaire Channel. In our daily communications with Palmer Station we learned that it was also the dominant organism in Arthur Harbor. Later in the day, while the Duke was at station in Dallmann Bay collecting glacial ice samples for Chris Carrillo's alkalinity determinations, Santa Claus himself (AKA Tony Amos in full dress) arrived by zodiac marking the official beginning of Christmas week aboard the ship.

We returned to Paradise Harbor and for nearly 16 hr out of the next 24 hr we kept the CTD (and associated sensors) deployed at a depth of approximately 5 m to determine the temporal variability in physical and optical characteristics of the water column. The resultant time series revealed numerous and coherent (e.g., high fluorescence associated with low light transmission, etc.) variations consistent with a physical control on biological variability.

Early in the morning of 22 Dec, we successfully recovered the bottom-moored sequencing sediment trap that had been deployed in conjunction with our coupled linkages among microorganisms study. We were pleasantly surprised to see the massive amounts of sedimented materials that were obtained during each of the 19 consecutive 6-hr collection periods. By visual inspection, the particulate matter appeared to be mostly krill fecal pellets suggesting that the krill are certainly capable of consuming this small cryptomonad. There do not appear to be enough diatoms in the water column to support the implied rates of export production at this site. The 6-hr resolution of the particulate flux measurements will also allow us to investigate diel and day-to-day variations in the grazing rates. We hope to collaborate with Ross/Quetin (S-028) on this aspect of the study.

We arrived at Palmer Station at 1030 hr on 22 Dec for cargo and personnel exchanges. As the final bow lines were being secured, Santa Claus emerged from the freezer van on the main deck -- he was well received by Station residents. By 2100 hr we were underway again for the northbound leg of our expedition and additional sample collections in Gerlache Strait, Deception Island and Drake Passage en route to Punta Arenas. We took a few hours out of this busy schedule to deploy a zodiac party onto RACER Rocks to inspect and, if possible, repair the automatic weather station (AWS) that was installed in 1989 during the RACER research program. Through the diligent efforts of Tony Amos, David Asselin (ASA) and Asbjorn Olsen (Polar Duke) this AWS is now back on line. By 1600 hr we were collecting water in the Two Hummock Island basin against a spectacular backdrop of giant icebergs, some grounded and others heading north in the Gerlache jet. We arrived at Deception Island at 0230 hr on 24 Dec and soon thereafter began our 5 station sampling program. I am preparing this report from our station in Fumarole Bay. We currently plan to complete our water sampling by 0900 hr, followed by a 8-10 hr holiday standdown so that scientists and crew members can have an opportunity to explore the local sites in Whalers Cove and the environs. It is a beautiful clear day at Deception so I expect the zodiacs to be full. Holiday festivities are planned to begin at 1700 hr and Santa is expected to appear (again)! We are scheduled to be underway for Punta Arenas by 1900 hr on 24 Dec and plan to spend Christmas and Boxing Day sampling waters of Drake Passage for a variety of biological and chemical properties.

PD94-12 Chief Scientist Report -- The Final Days

We completed our work in Deception Island at about 1000 on 24 Dec just in time to shuttle people ashore for some exploration, hiking and sampling of the hot springs. We obtained some incredible samples of the latter and the geothermal activity was greater than in previous years. Several scientists went swimming. At 1700 we were seated at a most impressive holiday dinner. After a few words of thanks and fellowship by the Captain (Karl) and the Chief Scientist (also Karl) we ate, drank and were generally merry until 1800 hr when the ship got underway for Drake Passage and beyond. Our holiday was extended a bit by calm seas, at least until after the present opening phase of the evening. We all received a very nice lead crystal "ice bird" from the Captain on behalf of Rieber shipping. At 2000 hrs all of S-046 headed for my cabin to discuss the Drake sampling plans and the Captain showed up with a case of Newcastle brown ale -- a gift from Faraday Station! By 2200 hr we were taking our first Drake Passage samples that continued at 3 hr intervals until a few hours ago. We are now madly getting the last of our gear packed or stored for the next leg. We are all still talking to each other -- a sign of a successful cruise. All in all it was a very productive and enjoyable trip. We are scheduled to arrive at the pier in Punta Arenas at 0600 hr on 27 Dec.

As this historic SANTA CLAµS cruise draws to a close, I would like to express my sincere appreciation to the Captain and Crew of the R/V Polar Duke for their outstanding support of our science programs, ASA staff aboard the ship, at Palmer Station and home in Denver for their service "above and beyond the call of duty" and to all the scientists aboard for making it happen. Planning is already underway for SANTA CLAµS-II!