98JanB LMG98-1: Annual cruise B (second leg) 28jan98-13feb98 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) was performed aboard the Research Vessel Abel-J (LMGR98-8: 18Jan-24Jan) while the full LTER grid (transect lines 600-200) and additional inshore station sampling were performed aboard the Antarctic Supply and Research Vessel Laurence M. Gould (LMG98-1: 28Jan-13Feb) with 15 crew, 5 Antarctic Support Associates, and 21 LTER participants. The first leg of the annual 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. As part of the Palmer LTER Education Outreach, Ms. Besse Dawson, a high school marine sciences teacher from Texas, was aboard ship as an NSF Teachers Experiencing Antarctica (TEA) participant. David Karl was mentor for the TEA. She communicated to online classrooms through real time field reports via the world wide web. Palmer LTER personnel also helped with the XBT Drake Passage Program (Ray Peterson, Dan Roemmich and Janet Sprintall) of Scripps Institution of Oceanography during the northbound Drake crossing. Sampling was done aboard the Laurence M. Gould (LMG98-1). David Karl served as chief scientist. Stations on grid line transects 600 through 200 were completed with 20 km station spacing on grid lines 600, 500 and 200 and at 40 km spacing on grid lines 300 and 400 using XBT's to fill at 10 km spacing. An average of 4 stations per day. Station 600.040 and inshore stations E&B were run at the end of the cruise. Adelie penguin diet samples were collected at Ginger Island toward the end of the cruise before proceeding to inshore stations in the South (Tickle Passage, Crystal Sound) and the North (Grandidier, Lemaire). Sampling West Coast of Antarctic Peninsula including near Palmer and LTER grid. Grid lines 500, 400, 300, 200, and 600 Inshore Stations: South and North Ginger Island bird sampling Sediment Trap Tickle Passage Palmer Stations E & B & H Ice-free open water was observed during most of the cruise. Brash ice was encountered in the Lemaire (inshore North) and Tickle Passage (inshore South). High winds were encountered on 18 January during coastal sampling, on 31 January preventing 600.200 offshore sampling and on 07 February during sampling of the mid 200 transect line. 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; the new sampling items included: 4) Ginger Island bird sampling 5) PA to Palmer XBT sampling in co-operation with J.Sprintall project 6) education outreach with Teacher Experiencing Antarctica 7) sediment trap Tickle Passage 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 and south (S) inshore (crystal Sound) each January from 1993 through 1998. Stations on grid line transects 600 through 200 were completed with 20 km station spacing on grid lines In order to simplify equipment and personnel support, the light and hydrographic measurements were performed on separate casts unlike the annual cruises (1993-1997). Profile measurements included hydrographic casts using the ship's CTD to 500m with twelve liter Go-Flo bottles run from a starboard Baltic Room as well as separate radiometer casts. Other measurements included microbial parameters, plant pigments, nutrients, primary production, plant physiology, and krill physiological measurements. Bio-acoustic transects and net tows were performed at 20 km spacing on all transect lines. Some planned acoustic work was canceled due to bubble sweep from the hull on the 3.5 kHz transducer port. Continuous underway measurement systems logged partial pressure of carbon dioxide, pH, dissolved oxygen, fluorescence, temperature and conductivity of near surface waters. An item that will be the subject of further discussions is the fact that compared to our former research vessel (Polar Duke), the Lawrence M. Gould affords much inferior visibility from its bridge for seabird and marine mammal censuses. See individual data sets. 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/98janb/* Karl, D., L.B. Quetin, and K.S. Baker, 1998. Palmer LTER: Annual January Cruises for 1998 (LMGR98-8; 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), D.Karl (Karl,S-046), W.Kozlowski (Vernet,S-016) L.Quetin (Quetin/Ross,S-028). National Science Foundation, Division of Polar Programs 08May00 Karen S. Baker David Karl

Study Form V1.3 for describing a collection of datafiles.