PALMER STATION SCIENCE SITREP AUGUST 1996 S-016 LONG TERM ECOLOGICAL RESEARCH (LTER) ON THE ANTARCTIC MARINE ECOSYSTEM: AN ICE DOMINATED ENVIRONMENT. PHYTOPLANKTON COMPONENT. Dr. Maria Vernet, Scripps Institution of Oceanography, Marine Research Division, La Jolla, CA. No personnel were on station. Station personnel collected and filtered weekly water samples for later analysis of chlorophyll content. S-024 ANTARCTIC MARINE ARCHAEBACTERIA; BIOLOGICAL PROPERTIES AND ECOLOGICAL SIGNIFICANCE. Edward DeLong, University of California, Marine Science Institute, Santa Barbara, California 93106. PERSONNEL ON STATION: Edward DeLong, Alison Murray, Christina Preston. In transit to Palmer Station, hydrocasts to 500 m were performed on July 29 on either side of the Antarctic Convergence, to test the hypothesis that the Polar Front may serve as a microfaunal, as well as macrofaunal, boundary. Picoplankton were collected from 20 to 30 liters at each of five depths for later phylogentic population structure analyses. Ancillary data on total prokaryotic abundance, temperature, salinity and relative fluorescence, were also collected. A similar hydrocast was also taken on August 1 at Dallmann Bay, where Murray and DeLong also participated in fishing for Detrich and DeVries. Many thanks to Greg Packard, Cole Mather and Leonard Lawbaugh, for their enthusiastic and professional assistance during these operations. Murray and DeLong arrived on station August 1, 1996. Brash ice filled most of Arthur Harbor on arrival. After station and lab orientation, the laboratory was set up and experiments began August 4. Preston arrived on station August 19 She collected surface seawater samples at two sites in transit along the Antarctic Peninsula to add to our sample database of the geographic distribution of the Archaea in the Peninsula region. Major objectives for this season include: 1) DOCUMENTATION OF ARCHAEBACTERIAL ABUNDANCE AND DYNAMICS IN ARTHUR HARBOR FROM LATE WINTER TO SPRING 1996. This years objectives include documenting ABSOLUTE archaeal cell abundance using in situ hybridization and quantitative epifluorescence microscopy, as well as documentation of relative rRNA abundance. Last years observations indicate a negative correlation between phytoplankton abundance, as indicated by chlorophyll concentration and archaebacterial abundance with archaebacteria dropping to a low relative abundance by November. Environmental conditions and biological parameters are also being monitored this season to verify last years observations. Since neither ice travel nor zodiac operations have been possible in August, samples are being taken from the intertidal zone off an ice pier and from the seawater intake system in the pumphouse. Last years rRNA and denaturing gradient gel electrophoresis (DGGE) analyses indicated few differences between bacterioplankton collected in raw seawater from the aquarium pumphouse, and that collected at Station A underneath the fast ice which formed there in 1995. Starting August 4, 1996, we have sampled at five day intervals at both locations filtering 40 liters per sample onto 0.2 um durapore filters for later extraction and analysis via quantitative oligonucleotide hybridization, and DGGE analyses. Concurrently, samples are collected for total prokaryotic cell counts by DAPI staining and epifluorescence microscopy, in situ hybridization experiments using epifluorescence microscopic analysis, chlorophyll determination and bacterial protein production both in the presence of and without bacterial inhibitors of protein synthesis, with hopes of assaying for Archaeal protein production activity. Dr. Ramon Massana arriving in early September will carry these studies on further. Preliminary PCR analyses of these samples on station again indicate a high relative abundance of Archaea. In situ hybridization analyses indicate a drop in total cell concentrations of Archaea over the month of August, with a coincident increase in the number of auto-fluorescent cells. The highest abundance was detected in the first samples we collected. In situ analyses are conducted with seawater, and on the concentrated cell suspensions generated by the hollow fiber filtration discussed below. 2. COLLECTION OF PICOPLANKTON BIOMASS FOR LIPID ANALYSES. To date, all characterized archaebacteria have been shown to have ether-linked phytanyl membrane phospholipids, instead of the fatty acid ester linked membrane lipids that are found in Bacteria and eukaryotes. To verify that this is a characteristic of antarctic marine planktonic archaea as well, one of our goals is characterization of the marine planktonic archaeal lipids. Large volumes of seawater (ca. 2000 liters per day @ 2 x 105 cells/ml) were filtered through 1.6 mm glass fiber filters, and the < 1.6 mm fraction concentrated via hollow fiber filtration (30,000 MW cutoff). The resultant picoplankton cells were then pelleted by centrifugation and stored frozen for later lipid characterization. >From August 4 to August 26, approximately 18,000 liters of Arthur Harbor seawater were concentrated via hollow fiber filtration. Each 2000 liter sample yielded approximately 50 mg wet weight of picoplankton cells. Since a significant proportion of the collected cells are archaebacteria, the resultant cell pellets should provide useful information regrading the lipid composition of Antarctic marine planktonic archaea, and potentially its evolutionary, ecological and adaptive significance. 3. LIPID BIOSYNTHETIC STUDIES To further characterize Antarctic archaeal lipids, 14C labelled acetate is being used to: a) study the effect of lipid biosynthesis inhibitors on acetate incorporation into the picoplankton lipid fraction b) Provide radiolabelled picoplankton lipids for later lipid analyses via TLC at UCSB. Experiments performed over the month of August indicated that Arthur Harbor picoplankton incorporate acetate into lipids at considerable rates at -1.5 C. Additionally, both inhibitors of eubacterial membrane lipid synthesis and archaebacterial membrane lipid synthesis reduced acetate incorporation into the lipid fraction of Arthur Harbor picoplankton substantially (ca. 30-50 % inhibition for each). Experiments at UCSB, derived from these and future experimental samples, will be used to: i) determine the presence or absence of fatty acid methyl esters and phytanyl ether moities in picoplankton lipids via TLC. ii) the effect of eubacterial and archaebacterial lipid synthesis inhibitors on the composition of labeled picoplankton lipids. Preliminary results are encouraging, and indicate high levels of acetate incorporation into the lipid fraction at in situ temperatures of -1.5 C, and potential eubacterial- and archaebacteiral-specific effects of the different lipid synthesis inhibitors. 4. PICOPLANKTON MICROCOSM STUDIES (PICOMS) Since the planktonic archaea have evaded cultivation as of yet, and hence, we have no specific information as to their physiology/biochemistry, we are running whole community (18 L/microcosm; < 1.6 - 1.0 mm seawater fraction) seawater culture experiments with hopes of obtaining insights into the physiological conditions under which archael abundance and activity is enhanced. These experiments allow us to address many interesting questions regarding the response of the prokaryotic community in contained systems. PICOMS are conducted under in situ conditions, we are testing a variety of enrichments in order to assay archaeal abundance relative to bacterial, and eukaryal. Initial experimentation determined the appropriate dilution that provides optimal growth in a reasonable experimental duration. Subsequent experiments have been initiated in which we are assaying a variety of substrates. Our plans are to test whether any of the enrichments enhance the archaeal "signal" as initially determined by in situ hybridization, and subsequently by QPCR and rRNA hybridization. Dynamics in community composition will also be investigated back at UCSB by DGGE. S-028 LONG TERM ECOLOGICAL RESEARCH (LTER) ON THE ANTARCTIC MARINE ECOSYSTEM: AN ICE DOMINATED SYSTEM. SECONDARY PRODUCTION COMPONENT. Drs. Robin M. Ross & Langdon B. Quetin, Marine Science Institute, University of California, Santa Barbara, CA. No personnel were on station. Station personnel transferred both the cultures living on station and several new cultures sent down on R/V POLAR DUKE to replace some cultures that had died. The light cycle was reset to mimic the natural winter light. These cultures are being cultivated throughout the winter for krill grazing experiments. S-037 STRUCTURE, FUNCTION, AND EXPRESSION OF COLD-ADAPTED TUBULINS AND MICROTUBULE-DEPENDENT MOTORS FROM ANTARCTIC FISHES. Dr. H. William Detrich, Northeastern University, Boston, MA. Personnel on station: A. Ramsey, and A. Saeed The goals of our program are to understand the molecular adaptations that enhance the function and expression of tubulins, microtubule motors, and globins from Antarctic fishes. During August, we completed our planned studies on fish cell culture optimization and on the functional analysis of the microtubule motor kinesin. Finally, the laboratory was packed and an inventory of stored materials prepared. On 06 August, A. Ramsey and A. Saeed (NU) departed Palmer for CONUS. We gratefully acknowledge the personnel of Antarctic Support Associates and the captain and crew of R/V Polar Duke for their excellent support of our winter season research program. Our heartfelt thanks to all, and our best wishes for a productive winter to those who remain behind. S-091 GLOBAL SEISMOGRAPH STATION AT PALMER STATION. R. Butler, Incorporated Research Institutions for Seismology (IRIS) No personnel were on station. The system has been monitored by the station science technician. Operations continued without interruption throughout the month. S-106 STUDIES OF LIGHTNING-INDUCED ELECTRON PRECIPITATION OF THE IONOSPHERE. U. Inan, Stanford University. No personnel were on station. The system has been monitored by the station science technician. On 21 August and 31 August, the narrowband system recorded less than the normal twelve hours of data. The truncated collection periods were probably caused by static discharges that may be related to high winds. Late in the month, two adjustments were made to the IF gain levels on the narrowband system. S-254 CHLORINE-AND BROMINE-CONTAINING TRACE GASES IN ANTARCTICA. Dr. R.A. Rasmussen, Oregon Graduate Institute for Science and Technology, Portland, OR No personnel were on station. Air samples are taken on a weekly basis by the station physician. The samples are returned to the Institute for analysis of a number of trace components, especially chlorine- and bromine-containing gases. These elements have been implicated in the chemical processes that contribute to the austral-spring depletion of the ozone layer over Antarctica. This work will contribute to a better understanding of the buildup of trace constituents, particularly those of high-latitude marine origin. S-257C COLLECTION OF ATMOSPHERIC AIR FOR THE NOAA\CMDL WORLDWIDE FLASK SAMPLING NETWORK. Dr James T. Peterson, Environmental Research Laboratories, National Oceanic and Atmospheric Administration, Boulder, CO No personnel were on station. Air samples are taken on a weekly basis by the station physician. The National Oceanic and Atmospheric Administration (NOAA) Climate Monitoring and Diagnostics Laboratory team continue long-term measurements of trace atmospheric constituents that influence climate. The Palmer Station air samples are returned to the NOAA laboratory for analysis of trace constituents, including carbon dioxide. These measurements are part of NOAA's effort to determine and assess the long-term buildup of global pollutants in the atmosphere. These data will be used to determine how the rate of change of these parameters affects climate, particularly by including them in climate model studies. S-275 UM/DOE-EML REMOTE ATMOSPHERIC MEASUREMENTS PROGRAM. J. Prospero/T. Snowdon, University of Miami; C. Sanderson, Department of Energy-Environmental Measurements Laboratory No personnel were on station. The system has been operated by the station science technician. One sample filter was exposed for the duration of each week, and a weekly schedule of calibration, background, and sample counts was maintained. An exposed filter was found to be somewhat snow covered when it was removed from the sampling apparatus on 23 August. The snow was carefully removed from the filter before the filter was bagged. T-312 TERASCAN SATELLITE IMAGING SYSTEM. R. Whritner, Scripps Institution of Oceanography No personnel were on station. The system has been operated by the station science technician. Throughout the month of August, the TeraScan system collected, archived, and processed DMSP and NOAA telemetry, maintaining a schedule of 15-17 passes per day. NOAA telemetry was archived for S-032 when the LTER grid was clear. Several processed DMSP images of the Palmer Archipelago region were transmitted to the R/V POLAR DUKE in support of vessel operations. Extensive communications with SeaSpace, Inc, led to the installation of several new software routines designed to minimize lost data during high elevation passes. One of the two tape drives used for data archiving failed and was replaced with a spare. T-513 UV MONITORING NETWORK. C. Booth, Biospherical Instruments, Inc. No personnel were on station. The system has been operated by the science technician. Throughout the month, raw irradiance data were collected daily and transmitted to BSI, and preliminary irradiances and integrals were produced in support of Science. "Season opening" absolute scans were performed on 12 August with both calibration lamps, and a scan was taken on 27 August with the site standard lamp. The auxiliary Eppley PSP sensor was releveled on 22 August. HV levels and the scan schedule were monitored throughout the month and adjusted as necessary to compensate for rapidly changing daylight conditions. ASA - SCIENCE SUPPORT NEWS, PALMER STATION Ms. Alice Doyle has been hired as the new Senior Assistant Supervisor, Laboratory Operations. Alice graduated from the University of Virginia with a Bachelor of Science in chemistry. For the past four years, Alice has worked at the Bermuda Biological Station as a research assistant. Her experience with HPLC's, autoanalyzers and salinometers will be invaluable in supporting Palmer Station grantees. She also has shipboard experience as a chief scientist on hydrographic cruises out of Bermuda and as a research assistant on a Ross Sea cruise of the R/V NATHANIEL B. PALMER. Alice is currently working in Denver, and will deploy in late October. Please join me in welcoming Alice to the Palmer team (doyleal.asa@asa.org). Teri McLain, the winter over lab supervisor, has returned to the states after a successful season supporting our winter science groups. Marian Moyher is now on site (moyherma@palmer.usap.nsf.gov) until mid-December. In addition to preparing for incoming science, current ASA science summer projects include preparation for a GPS base station and evaluation of our current weather data. And, for those of you with an eye towards the weather and sea-ice conditions: all transits of the Duke have been made in record time this season with little or no ice to hamper her progress. Though there has been some sea-ice in Arthur Harbor, there have been northern storms which have pushed most of the ice out to sea and has made the little remaining ice unsafe for travel. Zodiacs will be launched soon! The northern winds have also drastically decreased our land-based snow pack, and lots of rocks are already exposed.