98JanA LMGR8: Annual cruise A (first leg) 18jan98-24jan98 Annual sampling for the sixth Palmer Long-Term Ecological Research (LTER) January cruise was completed in two legs. Zooplankton sampling and bird observations within the foraging range of penguins near Palmer Station (high density grid) were performed aboard the Research Vessel Abel-J (LMGR8: 18Jan-24Jan) with 5 crew and 9 LTER science participants. Stations were held on the inshore portion of the 600 transect line and at selected Northern inshore stations. The full LTER grid (transect lines 600-200) and additional inshore station sampling was performed subsequently aboard the Antarctic Supply and Research Vessel Laurence M. Gould. The cruise began one week later than the preceding annual LTER cruises (Ross and Baker, 1997) with the charter of the Abel-J for the first leg of the cruise because of the end of RV Polar Duke contract and the delay in the maiden voyage of the newly built ASRV L.M.Gould. On 22 January batteries were replaced at the the Hugo Automatic Weather Station (AWS). The AWS electronics box was removed in order to replace components and returned on 24 January restoring the station to full functionality. Time at Hugo permitted a complete bird survey of the Hugo archipelago. Sampling was done aboard the R/V Vessel Abel-J (LMGR8). Langdon Quetin served as chief scientist. Initial nearshore Palmer work on the first cruise leg included repeat visits to nearshore stations (E, B, H, I, J), two transects (picket lines) which maintained a fixed distance from Palmer Stations (PL 3.7 and 10 km), and one high density grid (HD1 10 km x 20 km) with five hydrographic stations. Stations on the LTER mesoscale grid were occupied including (600.040, 060, and 080) followed on 23 January by four inshore stations in the Lemaire and Grandidier. Sampling West Coast of Antarctic Peninsula including near Palmer and LTER grid. Palmer Stations E & B & H Grid line 600.080, 600.060, 600.040 Picket lines 3.7, 10 High Density Grid: 20km Inshore Stations: North AWS Hugo Repair Ice-free open water was observed during most of the cruise. Brash ice was encountered in the Lemaire (inshore North). High winds were encountered on 18 January during coastal sampling. Ship-based censuses in the Adelie penguin foraging area from both the Abel-J and the Gould suggest that birds were concentrated inshore within 15 km of their rookeries. This pattern is in agreement with other data, including shorter foraging trip durations relative to the 96-97 season and the presence of large numbers of small krill in their diets. Chlorophyll concentrations indicate low phytoplankton standing stocks throughout the study region averaging less than 1-2mg Chl/m3 even in the nearshore stations. The frequently observed onshore-to-offshore gradients in chlorophyll [Smith et al, 1998] are minimal this year as they were last year. Further, the South to North chlorophyll gradient is entirely absent. Surface dissolved oxygen and dissolved carbon dioxide concentrations indicate that both biogenic gases are essentially at equilibrium with the atmosphere unlike previous years with supersaturated dissolved oxygen and undersaturated carbon dioxide. Indications are that primary production is low compared to previous years. Large interannual variations in magnitude and timing of the spring-summer export have been documented. The 96-97 sediment trap samples gave dramatic visual evidence for a large export flux event for a period of about two weeks during late December 1996-early January 1997, but no comparable export event was observed in the 97-98 samples through this past austral summer prior to 8 January 1998. How the ecosystem changes observed relate to the 1997-98 El Nino events will be the subject of further investigation. A central tenet of the PAL is that the annual advance & retreat of sea ice is a major physical determinant of spatial & temporal changes in the structure & function of the Antarctic marine ecosystem, from total annual primary production to breeding success in seabirds. Evaluation is ongoing of a number of testable hypotheses linking sea ice to 1)the timing & magnitude of seasonal primary production, 2)the dynamics of the microbial loop & particle sedimentation, 3)krill abundance, distribution, & recruitment, and 4)the breeding success & survival of apex predators. The PAL program includes spatial sampling during annual & seasonal cruises in portions of our regional grid in the Western Antarctic Peninsula region & temporal sampling from spring through fall (October to March) in the area adjacent to Palmer Station. The program is designed to sample at multiple spatial scales within one regional scale grid, permitting repeated sampling on both seasonal & annual time scales, thus addressing both short & longterm ecological phenomena, as well as providing a basis for specific mechanistic studies. Sampling is designed to (1) document interannual variability along and offshore (2) to investigate the linkage between the marine resources and the Adelie penguins nesting near Palmer Station when sampling is within the foraging range of the penguins during a time of peak food requirements for the chicks; and (3) to continue the seasonal sampling at the Palmer grid (nearshore stations) to document interannual variability and consistency in patterns seen throughout the growing season from November to March. This cruise specifically continued: 1) cardinal grid line sampling; 2) repeated near shore station sampling; 3) inshore grid station sampling; 4) picket line bird census at 3.7km and 10km 5) high density foraging grid; 6) zodiac bird observations; 7) PA to Palmer XBT sampling in co-operation with J.Sprintall project; ?) acoustics run with picket line surveys; the new sampling items included: 9) Hugo AWS repair and bird survey; ?) Hugo bird survey; The picket line bird censuses were continued from Jan95 and Jan96 to Jan97 to document the bird foraging range since earlier penguins were observed as far as 200km to sea. The acoustics measurements were added to the 3.7km pickets in order to tie together temporally bird observations and krill location. The high density grids were developed to focus on specific sampling areas. While a fixed approximately 70kmx70km near-Palmer grid was repeated twice in Jan93, a fixed 50kmx50km near-Palmer grid was run once in Jan94. High density grids based on the picket line bird foraging results were introduced in Jan95 and continued in Jan96 to focus on the 20km range off Torgersen Island. For Jan97 the 10kmx20km grid run twice, once in forward order and once in reverse order, with 2.5 km resolution for bird observation and acoustic biomass and with 5 km resolution for hydrographic sampling. The 10kmx20km grid was run once in 1998. Investigation of larval fish (1m net) hypothesized to be important for skuas takes place through sampling of north (N) inshore (Biscoe-Renaud/Lemaire/Grandidier) in Jan94,Jan95,Jan96,Jan97, and Jan98. Station measurements included optics using a profiling radiometer and hydrography using the station CTD deployed to a depth of 100m. Six 5 liter Go-Flo bottles deployed routinely from the port side using a hand winch collected water for nutrients, plant pigments, primary production, and plant physiology. A Palmer zodiac was used to collect krill. Bioacoustic surveys were completed aboard the Abel-J at 4.5 knots, the ship's minimum speed. Water for nutrient and productivity measurements was taken back to Palmer station. Nutrients were shipped to the University of California at Santa Barbara Analytic Facility for analysis. See individual data sets for further details. Core measurements available two years after the cruise. Citation acknowledgement: "Data from the Palmer LTER data archive were supported by Office of Polar Programs, NSF (OPP-9011927)." antarctic, southern ocean, bio-optics, phytoplankton, krill, marginal ice zone ~lter/data/98jana/* Karl, D., L.B. Quetin, and K.S. Baker, 1998. Palmer LTER: Annual January Cruises for 1998 (LMGR8; LMG98-1). Antarctic Journal of the United States. This research cruise was composed of the Palmer LTER research team including team leaders P.Duley (Fraser,S-013), C.Johnson (Smith,S-032), W.Kozlowski (Vernet,S-016), L.Quetin (Quetin/Ross,S-028). National Science Foundation, Division of Polar Programs 08May00 Karen S. Baker Langdon Quetin

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