96Jan PD96-01: Annual cruise 08jan96-10feb96 Annual austral summer LTER time-series cruise carried out in several sections with repeated sampling of inshore stations (gridlines 500,600; pickets,grids/HD1/PLRadial/HDBismark/,accoustics/200m,zodiacs; inshore North/Lamaire,Grandidier; picketMulti; gridlines 400,300,200,Rothera; Marguerite Bay; inshore South/Crystal Sound) Standard transects were run at LTER grid lines 600, 500, 400, 300, 200. Standard inshore stations 'North' and 'South' were occupied. Bird picket fence surveys were continued from last year with the systematic sampling strategy aimed at quickly determining in which direction the penguins forage. The bird foraging sampling included methods: picket-line (PL) sampling, high density grid (HD) as well as the zodiac observations. Inshore stations B to E were occupied four times throughout the cruise while B and E were occupied one additional time to provide a time-series of the inshore grid. Besides adding accoustics measurements to the last four 3.7km picket lines, an accoustics run was made along the 200km contour to the east of the Palmer Basin and on the south side of the Bismarck Strait. Three days of ice and sediment trap work were done at Marguerite Bay. A special one day bird survey from Torgersen Island was conducted. Five attempts were made to approach Hugo Automatic Weather Station (AWS). Two of these attempts failed due to high seas making small boat landing unsafe. On the other three visits the batteries were replaced, a water temperature probe installed (but failed), the solar panel direction adjusted, and the windvane replaced with one from Bonaparte AWS since the bearings were worn. A visit was made to the British Antartic Survey (BAS) Station at Rothera in order to further communications about their new near shore sampling program. Sampling was done aboard the R/V Polar Duke PD96-1. Maria Vernet served as chief scientist. Standard transect sampling protocol included an average of 4 stations per day using 20km grid for BOPS with XBT between stations (10km grid). Station sampling included: BOPS, phytoplankton productivity, nutrients, and zooplankton including krill observations. The CTD was used at selected stations for deeper profile information. There were thirteen picket lines run including eight 3.7km pickets lines, three 10km picket lines, one 30km picket line, and one multipicketline. There were three high density grids run including a repeat of HD1 from Jan95 cruise as well as a grid within the Bismarck Strait area (HDBis). Also a new radial picket line (PLR) was run to investigate whether counting in the direction of travel impacted a survey. Zodiac bird observations were conducted eight times to determine direction of travel. Sampling West Coast of Antarctic Peninsula including near Palmer and LTER grid. Palmer Stations B-J Grid lines 500, 600, 400, 300, 200 High Density Grid: 20km, radial, Bismark Picket lines 3.7, 10, 30, multi Inshore Stations: North; South Marguerite Bay ice/sediment trap work Torgeson Island Bird Experiment Rothera Station Open water West of the Antarctic Peninsula. Ice encountered at the southern part of Grandidier (grid inshore north), in the southern part of Crystal Sound (grid inshore south), and in the southern part of Marguerite Bay. During the cruise most bad weather days happened while the ship was near shore so was not disruptive except for the 05 Feb storm when a day was lost. There was a strong variability in penguin distribution with most birds feeding within 3.7km of Torersen Is. on 9Jan, within 10km of Torgersen Is. on 16Jan, and within 30km of Torgersen Is. on 25Jan. Krill were observed everywhere with main concentrations nearshore and along the 200-m contour line. During this time, krill changed from a loose distribution in layers to more defined swarms. Phytolankton biomass was high with a large diatom bloom observed near Palmer Station and extending to 600.080 and the Lamaire Channel midJanuary. 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 LTER annual time series investigations are continued using the standard sampling in addition to old and new high density penguin foraging patterns as well as several short focused experiments at Marguerite Bay and Torgersen Island. 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 & long-term ecological phenomena, as well as providing a basis for specific mechanistic studies. This cruise specifically included: 1) cardinal grid line sampling; 2) repeated near shore station sampling; 3) inshore grid station sampling; 4) picket line bird census at 3.7km, 10km, 30km and multi; 5) high density foraging grids; 6) zodiac bird observations; the new sampling modes included: 7) targeted tows with opening,closing nets; 8) accoustics run with picket line surveys; 9) accoustics run along 200m contour on the east edge of Palmer Basin; 10) picket line Bismark area; 11) Marguerite Bay water column/sediment trap experiments; 12) Torgersen Island bird experiment; The summer cruises (Jan93,Jan94,Jan95,Jan96) have had surveys of the 600,500,400,300,200 lines except Jan94 which did not include the 200 line. The standard measurements along these lines included: optics, hydrography, microbial loop measurements, plant pigments, primary production & physiology, acoustic surveys & net tows for zooplankton, krill & fish (3 nets). The picket line bird censuses were continued from Jan95 in Jan96 to document the bird foraging range since earlier penguins were observed as far as 200km to sea. The accoustics measurements were added to the last four 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. 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 and sampling of south (S) inshore (Biscoe-Levoisier/Crystal Sound) in Jan93,Jan94,Jan95,Jan96. There have been sediment traps consistently off Hugo Island. A third trap was moved from Hugo to Crystal Sound (Mar93/Dec93) and later moved to Paradise Bay. Investigation of phytoplankton physiology by taking several diurnal stations along standard transect lines (Jan93) See individual data sets. Core measurments 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/96jan/* Vernet, M. and KS Baker, 1996. Palmer LTER: Annual January Cruise for 1996 (PD96-1). Antarctic Journal of the United States. National Science Foundation, Division of Polar Programs 24Apr96 Karen S. Baker Maria Vernet

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