PALMER STATION SCIENCE SITREP JANUARY 1998 William R. Fraser, SSL NEWS FROM THE LAB. Rob Edwards, Senior Assistant Supervisor, Laboratory Operations As we reached the height of summer on Anvers Island, Palmer Station has been a busy place. Researchers from seven U.S. Antarctic Program projects have been working in the labs and performing field work in the local area. Four of the projects are part of the Antarctic Marine Long Term Ecological Research site (LTER). This year, the summer LTER research cruise, which covers a large scale grid in the Bellingshausen Sea, southwest of Palmer Station, has been utilizing two vessels, the R/V Abel J, and our new research and supply vessel, the R/V Laurence M. Gould. Both vessels have also been involved in the transport of scientific and operational cargo. Final cruise planning, transfer of equipment, supplies and personnel between vessels and station, while continuing local research efforts, has kept station staff and researchers very busy. Flexibility has been the watchword on station this month, as cruise schedules and conditions continued to evolve. January is also the height of the tourist season, as there were four cruise ship visits and numerous private yachts in the local area. The past month was a bit cloudier and wetter than December, with 27 overcast days, and 26 days with measurable precipitation. The average air temperature jumped up almost one and one half degrees to 2.9 C, while the surface ocean temperature stayed close to +1 C throughout the month. Wind and ice conditions have both stayed moderate, with good boating access to the islands and local sampling stations. There is very little snow left near station and on the Glacier front. Macroalgae are growing rapidly in intertidal areas, and water clarity has greatly decreased, presumably due to blooming phytoplankton. The laboratory consumable supplies Milvan was cleaned up and reorganized, with the aim of making stock more accessible to all users as well as being easier to resupply. While the variety and number of research projects on station has been increasing over the last few years, the storage space has not. We are trying to continue incorporating suggestions from local users into the usage of science storage space, to result in more efficient utilization of space while remaining adaptable to the needs of different research groups. The arrival of the R/V Laurence M. Gould (LMG) at Palmer Station this month marks a significant change in Peninsula Area operations of the U.S. Antarctic Program, replacing the R/V Polar Duke. The vessel is operated by Edison Chouest Offshore under charter agreement with the National Science Foundation. Due in part to delays in the LMGs completion, research facilities on the vessel have been enhanced. The ship's operational and research capabilities will be tested over the next six months during scheduled cruises. Here at Palmer Station, we are very pleased that cargo offload and setup for the LTER cruise went smoothly. Laboratory equipment from Palmer Station is being used during the cruise, and can be shared between ship and station laboratories when there are not conflicting uses. The following programs were involved in research at Palmer Station: S-003 OZONE DEPLETION, UV-B RADIATION AND VASCULAR PLANT PERFORMANCE IN ANTARCTICA. Thomas A. Day, Department of Plant Biology and the Center for the Study of Early Events in Photosynthesis, Arizona State University, Tempe, AZ 85287-1601. PERSONNEL ON STATION: Thomas A. Day, Christopher T. Ruhland and Fusheng Xiong. Studies continued on the influence of UV radiation and warming on the two antarctic vascular plants Deschampsia antarctica (hair grass) and Colobanthus quitensis (pearlwort). We continued assessing photosynthesis, growth and reproductive performance of plants under experimental treatments that reduce ambient levels of UV radiation, along with passively raising temperatures around plants. While these manipulations have lead to some large responses in some plant parameters over the prior two growing seasons, effects on many parameters have been relatively subtle. However, we have found very large responses in most measured parameters in response to our manipulations this growing season. We suspect the slow-growing nature of these species has prevented us from detecting large treatment effects until our current (third) growing season. One of the more noteworthy findings from this month's sampling, which corroborates trends from last season, was that ambient levels of UV radiation substantially reduced leaf length and leaf production in both species. More leaves were produced and these leaves were larger when ambient levels of UV-B radiation were reduced. This effect was even more pronounced when both UV-B and UV-A radiation were reduced. Our findings to date suggest that these UV-induced growth reductions are not due to lower photosynthetic rates. We also found that plants under ambient UV levels produce more UV-screening compounds than plants under reduced levels of UV. We are currently examining the hypothesis that the production of some of these UV-screening compounds in response to high UV radiation levels may be indirectly responsible for reductions in leaf growth; some of these compounds accumulate in the cell wall of the leaf epidermis and we suspect they may constrain cell expansion and ultimately limit leaf growth and size. While UV radiation has a negative effect on leaf growth, it appears to have a positive effect on reproductive output in these species: reproductive structures on plants growing under ambient levels of UV radiation were much more developed than those on plants under reduced levels of UV. It is unclear whether this is a UV-specific photomorphogenic response or merely a general stress response, since plants typically produce more flowers in response to a large variety of environmental stresses. Our warming treatments are having a beneficial effect on the vegetative growth and reproductive output of both species. Plants under warming produced more leaves and these leaves were longer than those at ambient temperatures. Reproductive structures on plants under warming treatments were also much more developed than those on plants at ambient temperatures. We also found that on most days the net photosynthetic rate or CO2 uptake rate of leaves under warming is improved compared to those under ambient temperatures. The exception is on warm sunny days, when photosynthetic rates are depressed under warming. This depression appears to be due largely to temperature-enhanced respiration rates; at higher temperatures these plants have very high respiration or CO2 evolution rates which effectively reduce or tend to swamp out photosynthesis or CO2 uptake. Another mechanism involved in these depressions in photosynthesis at higher temperatures may be the inactivation of photosynthetic enzymes. To assess this, leaf samples were collected in December and January in parallel with photosynthesis measurements, and will be analyzed at ASU for activity of key photosynthetic enzymes. In addition to our experiments on climate change and plant performance, we visited the Joubin Islands on 26 and 27 January in conjunction with science groups S-013 (Bill Fraser) and S-007 (Deneb Karentz). Botanists who have previously visited this group of over 100 islands have not found any vascular plants, and the consensus was that vascular plants had yet to establish in these islands. We visited over 100 islands in search of vascular plants and found populations of Deschampsia on two of these islands. Deschampsia plants on both islands were restricted to north-east facing moss banks within 100 m of shoreline. These two islands were adjacent to each other, with the grass populations about 300 m distant. One island contained a population of over 415 Deschampsia individuals that occurred for about 80 m along a north-east shoreline. This population included small patches of grass turf, consisting of nearly continuous grass cover, that were up to 1 m by 0.5 m in area. The population on the other island consisted of 218 scattered individuals making up of four localized groups that were within 100 m of each other. No Colobanthus quitensis were found in the Joubin Islands. We thank Antarctic Support Associates personnel, other science groups on station, and the crew of the Abel-J for helping make this a highly productive month. S-007 UV-PHOTOBIOLOGY OF PLANKTONIC DEVELOPMENTAL STAGES OF ANTARCTIC BENTHIC INVERTEBRATES. Deneb Karentz, University of San Francisco and Isidro Bosch, State University of New York at Geneseo. PERSONNEL ON STATION: Deneb Karentz, Mario Pineda and William Jaeckle The focus of our work this season has been to determine the extent to which levels of UVB in Antarctic surface waters affect the development and survival of the planktonic developmental stages (gametes, embryos, larvae) of selected benthic marine invertebrates (seastars, urchins and limpets). Our research effort involves sampling of natural plankton populations and manipulations of specimens reared in the laboratory, including experiments in outdoor tanks and in situ. This month we completed our studies of the effect of UV on the development of the sea urchin Sterechinus neumayeri. Adult sea urchins had been artificially spawned to initiate cultures of embryos that were reared up to the pluteus stage in outdoor growth chambers under ambient light conditions. The effects of UV exposure on various developmental stages (zygotes, blastula, gastrula and plutei) from outdoor ambient light experiments and dose responses with artificial light sources were examined. Observations included documentation and quantification of morphological changes, developmental delay, lethality, DNA damage induced by UV exposure and changes in concentrations of UV-absorbing compounds (mycosporine-like amino acids: MAAs). Much of our time this month has been devoted to the processing of Sterechinus samples for DNA and MAA analyses. Work has continued on monitoring temporal changes in the concentration of MAAs in different tissues (body, gonad, digestive tract and shell) of the limpet Nacella concinna. Nacella is a dominant shallow water benthic species in the Palmer Station area and as such is exposed to the highest levels of UV in the marine environment. Weekly intertidal collections of adults are being analyzed by HPLC for the quantification of specific MAAs (shinorine and porphyra-334). As expected from previous work, highest concentrations of MAAs are found in the ovaries. Ancillary collections of the red macroalga Iridea chordata and benthic diatom mats are also being made once a week to determine if there is any correlation between MAA content of limpets and that of their potential food sources. HPLC analyses of I. chordata and the diatoms indicates the presence of at least four MAAs (mycosporine-glycine, shinorine. porphyra-334 and palythine). In addition to the field monitoring program, limpets have been maintained in outdoor tanks with various UV filters (total sunlight, sunlight minus UVB, sunlight minus UVA and UVB). Animals and the diatoms growing in these tanks have been sampled once a month since October. These data, along with the weekly field collections, will be used to document the responses of Nacella to UV light exposure. During the past month we have been able to spawn adult Nacella in the lab. Cultures of embryos and larvae (up to the veliger stage) have been initiated and are being maintained in outdoor tanks. Dose responses and in situ incubation experiments have been conducted as described above for Sterechinus to document and quantify morphological changes, developmental delay, lethality, MAA content and DNA damage induced by UV exposure. A major effort this month has been to characterize the distribution and abundance of larval plankton in the water column relative to hydrographic conditions (temperature, salinity, light). Seacat CTD data (temperature, salinity and density) and Biospherical PUV data (UV radiation and visible light) are being collected in conjunction with opening/closing net tows taken at six depths from the surface to 30 m. Maximum numbers of larvae have been collected mostly between 10 and 20 m depths. The larvae of the common sea star (Odontaster) and the pilidium larvae of nemertean worms continue to be the most abundant meroplankters. In order to assess the potential UV exposure of various planktonic groups, we have been trying to determine whether or not benthic invertebrate larval stages demonstrate any vertical migration patterns in the Arthur Harbor area. Net tows (for both zooplankton and phytoplankton) have been made at various times of day. While distinct depth profiles have been observed (as mentioned above), diel changes were not sufficiently documented. Unfortunately, late night sampling from Palmer Station is limited for safety reasons. On January 26 and 27 we had a wonderful opportunity to sample the plankton from the R/V Abel-J. We towed opening/closing nets at six depths (0-30 m) every six hours for a 24-hour period. These tows from the Abel-J allowed us to tow for a longer time period than possible by Zodiacs (consequently filtering more water), as well as to sample over a complete diel cycle in an effort to document possible temporal depth differences in larval abundance. The results of this one sample series suggest that the benthic invertebrate larvae probably do not migrate vertically. Seastar and worm larvae were again most prevalent with maximum densities between 15 and 20 m. S-007 will depart Palmer Station on February 15. We would like to thank all of the ASA personnel at Palmer and those in Denver who have contributed to our very successful field season. S-013 CHANGES IN ADELIE PENGUIN POPULATIONS AT PALMER STATION: EFFECTS OF LONG TERM HUMAN DISTURBANCE AND ENVIRONMENTAL CHANGE. William R. Fraser, Montana State University. PERSONNEL ON STATION: William Fraser and Donna Patterson. The focus of this research, which is in its final season, has been to understand how natural vs. human-induced perturbations affect the demography of Adelie Penguins. As background data, we have more that a decade of uninterrupted research on Adelie Penguin population dynamics at sites free of human disturbance. It is against this time-series that we contrast how Adelie Penguin demography responds to human effects, which in the Palmer area have historically been restricted to only one side (the "tourist side") of Torgersen Island. Our approach each season has emphasized obtaining demographic measurements at several scales (individuals, colonies, rookeries) in areas free of human activity and in areas where tourism occurs. In the latter, we have also monitored and mapped "tourist flow" with the idea of understanding how impacts may be distributed across the landscape. During January, four tour vessels and one private sailboat visited the Palmer area and 382 tourists spent 20-60 minutes each on Torgersen Island. As in past seasons, tourist distributions were not random, with some colonies within the rookery receiving a disproportionately high amount of attention. Because at this writing not all chicks have creched and various population censuses still remain to be done, we cannot yet contrast this season's data with past work. We expect to have more definitive conclusions available in February after data collection from the 600 nests sites and 25 colonies we are monitoring is completed and assessed. S-016 LONG-TERM ECOLOGICAL RESEARCH ON THE ANTARCTIC MARINE ECOSYSTEM: AN ICE-DOMINATED ENVIRONMENT (PHYTOPLANKTON COMPONENT). Maria Vernet, Scripps Institution of Oceanography. Personnel are temporarily off Station and reporting their progress through the L.M. Gould network. S-028 LONG-TERM ECOLOGICAL RESEARCH ON THE ANTARCTIC MARINE ECOSYSTEM: AN ICE-DOMINATED SYSTEM. Robin M. Ross and Langdon B. Quetin, University of California, Marine Science Institute, Santa Barbara. Personnel are temporarily off Station and reporting their progress through the L.M. Gould network. S-032 LONG-TERM ECOLOGICAL RESEARCH (LTER) ON THE ANTARCTIC MARINE ECOSYSTEM: AN ICE DOMINATED ENVIRONMENT. Ray Smith, University of California at Santa Barbara. Personnel are temporarily off Station and reporting their progress through the L.M. Gould network. S-035 LONG TERM ECOLOGICAL RESEARCH ON THE ANTARCTIC MARINE ECOSYSTEM: AN ICE-DOMINATED ENVIRONMENT (Seabird Component). William R. Fraser, Montana State University PERSONNEL ON STATION: William R. Fraser, Peter Duley and Matt Irinaga. Research related to this program is closely coupled with the activities associated with S-013, but objectives diverge to focus more specifically on understanding how annual variability in the marine (foraging) and terrestrial (breeding) environment affects Adelie Penguin demography. In effect, S-035 contributes to S-013 by providing necessary background data. It also contributes to the U.S. Antarctic Marine Living Resources Program as part of national activities related to CCAMLR and SCAR. January activities included the onset of diet and foraging studies, the continuation of ongoing monitoring of nest sites to determine breeding success and chronology, and a variety of area-wide, colony-scale censuses to assess population trends. Diet sampling commenced on 06 January and has been repeated at 5-day intervals. Prey has consisted mainly of Euphausia superba in the 31-40 mm range. Only four samples have contained Thysanoesa macrura and fish and amphipods have been rare. Diet sampling will continue through the fledging period and likely conclude by 20 February. Thirty-seven radio transmitters were deployed on 05 January to obtain data on foraging trip durations. Data collection will continue throughout the fledging period for both these parameters. Preliminary data on breeding success are available only for Humble Island where breeding chronology is typically more advanced than for other rookeries in the Palmer area. This season we recorded a success rate of 1.60 chicks per pair as opposed to 1.48 chicks per pair last season, although the number of 2-chick broods decreased slightly (64% vs. 67%). Censuses for the Humble and other rookeries suggest a slight increase in the overall number of breeding pairs. As in past seasons, data on other species are obtained on an opportunistic basis. In this regard, South Polar skuas are exhibiting poor breeding success, with only 25 breeding attempts noted at our Shortcut Island long-term study site. Current estimates of Brown skua productivity suggest improved success relative to last season (1.78 vs. 1.25 chicks/pair). We are also continuing collecting data on the basic breeding biology of Blue-eyed shags and Giant Fulmars. Censuses of marine mammal populations continues on all islands as well. On 26 January, the S-013 and S-035 field teams departed Palmer on the R/V Abel-J for a two-day exploration of the Joubin Islands (see S-003 and S-007). Our objectives were to locate and census penguin colonies that have not been censused since 1985, but for which a time series exists that began in the mid-1970's. Good weather permitted us to investigate more than 100 islands and locate all the historical colonies, thus obtaining censuses for Adelie, Chinstrap and Gentoo penguins. Comparisons with the historical data reveal a 75% decline in Adelie populations, an 80% increase in Gentoos and a stable Chinstrap population, which agrees with models we have developed relating climate change to ecosystem responses. We would like to thank Captain Bob Wallace and the crew of the R/V Abel-J for outstanding support and assistance during this work. Special thanks are also due to ASA's Sheldon Blackman for outstanding assistance with our telemetry and communications needs, Randy Sliester for coordinating and maintaining our Zodiacs and Mark Rosen for his patience in accommodating our meal schedules and field food provisions. Doug Conlin (S-028/S-032) provided valuable assistance with field work in early January. S-085 GPS CONTINUOUS OPERATION REFERENCE STATION. J. Mullins, U.S. Geological Survey The station science technician has monitored the system. For the month of January, GPS data was collected nearly continuously. Daily data was converted to a RINEX format, compressed, and FTPed to Reston, VA. The average daily data transfer to Reston was 2.65 MB. During the month of January, the new Ashtech Reliance system was set up and tested. In order to establish consistent communication between the base station and Reliance system, it was necessary to adjust the base station's RTCM bit rate from 25 to 300. After this change, the Reliance system was successfully operated in real time corrector mode. On 27 January at approximately 0400 UT, the frequency on the station's electrical generation system drooped momentarily to 41Hz. The power glitch caused the CORS PC to reset. As a result, data collection was down for approximately 10 hours, until the problem was spotted and corrected. S-091 GLOBAL SEISMOGRAPH STATION AT PALMER STATION. R. Butler, Incorporated Research Institutions for Seismology (IRIS) No personnel were on station. The station science technician has monitored the system. On 27 January at approximately 0400 UT, the frequency on the station's electrical generation system drooped momentarily to 41Hz. The glitch somehow disabled the printout of the helicorder charts. A reset of the data processor restored the auto_helem process and chart printing was restored. On 23 January, a new tape change procedure was implemented as Requested by ASL. S-106 STUDIES OF LIGHTNING-INDUCED ELECTRON PRECIPITATION OF THE IONOSPHERE. U. Inan, Stanford University No personnel were on station. The station science technician has monitored the system. Throughout the month of January, the nightly narrowband data collection was plagued by frequent truncation of the recording session. For the month, 17 of 31 narrowband recordings were shortened sessions. All other Stanford VLF operations were normal. On 27 January, the VLF antenna and feedline were inspected. Most of the feedline support posts had melted out of the glacier, but the antenna was in good condition. The feedline cable was moved out of any melt holes to prevent it from freezing into the ice. S-204 MEASUREMENTS OF ATMOSPHERIC O2 IN RELATION TO THE GLOBAL CARBON CYCLE. Ralph Keeling, Scripps Institution of Oceanography No personnel were on station. Air samples are collected on a semi-weekly basis by the station physician. The samples are return shipped to Scripps for analysis of O2 and CO2 content. The goal of the program is to resolve seasonal and interannual variations in atmospheric O2 (detected through changes in O2/N2 ratio) which can aid in the determination of rates of marine biological productivity and ocean mixing and aid in the separation of the global sink for anthropogenic CO2 into terrestrial and oceanic components. The program involves air sampling at a network of sites in the Northern and Southern Hemispheres. Palmer Station is especially well situated to resolve signals due to carbon cycling in the Southern Ocean. S-254 CHLORINE-AND BROMINE-CONTAINING TRACE GASES IN ANTARCTICA. R.A. Rasmussen, Oregon Graduate Institute for Science and Technology 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. James T. Peterson, Environmental Research Laboratories, National Oceanic and Atmospheric Administration 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. C. Sanderson, Department of Energy, Environmental Measurements Laboratory No personnel were on station. The station science technician has operated the system. One sample filter was exposed for the duration of each week, and A weekly schedule of calibration, background, and sample counts was maintained. T-312 TERASCAN SATELLITE IMAGING SYSTEM. R. Whritner, Scripps Institution of Oceanography No personnel were on station. The station science technician has operated the system. On 26 January, the cooling fan on the HR-100 receiver failed. The fan was replaced with a site spare. One scheduled pass was missed as a result of the repair. Throughout the month of January, the TeraScan system collected, archived, and processed DMSP, NOAA, and ORBVIEW-2 telemetry, maintaining a schedule of 17-19 passes per day. NOAA, DMSP, and ORBVIEW-2 telemetry were archived for S-032 when the LTER grid was clear. AWS transmissions were monitored from Bonaparte Point, Hugo Island, and RACER Rock. During the month, extensive ice/weather support was provided to various groups. Recipients of TeraScan imagery included the R/V L. M. Gould, McMurdo Station, the SCAR Epoch '98 Campaign, and visiting tourist ships. On 03 January, the Hugo Island AWS stopped transmitting data. The Science Technician and Electronics Technician visited Hugo Island on two separate occasions to facilitate the necessary repairs. Several failed electrical components were replaced in the AWS electronics and fresh batteries were installed. The Hugo AWS was returned to service on 25 January. T-513 UV MONITORING NETWORK. C. Booth, Biospherical Instruments, Inc. No personnel were on station. The station science technician has operated the system. Throughout the month, raw irradiance data were collected daily and transmitted to BSI, and preliminary irradiances and integrals were produced in support of Science. Scheduled absolute calibration scans were performed on 15 January and 29 January. On 24 January, as requested by BSI, a wavelength calibration and calibration of the wavelength potentiometer were performed. -- End --