SUBMITTED: Antarctic Journal/10Nov97 REFERENCE AS: Ross, R., and K. S. Baker, Palmer LTER: Annual January Cruise for 1997 (PD97-1), Antarct. J. U. S. 1997. Palmer LTER: Annual January Cruise for 1997 (PD97-1) Robin Ross and Karen S. Baker Marine Science Institute University of California at Santa Barbara Santa Barbara, CA, 93106 Marine Research Division Scripps Institution of Oceanography University of California at San Diego San Diego, CA, 92122 Each year since 1993, the Palmer Long-Term Ecologi- cal Research (LTER) program has surveyed a mesoscale study region west of the Antarctic Peninsula with a stan- dard grid that was set up at the initiation of the pro- gram (Waters and Smith, 1992). During the 1997 cruise aboard the R/V Polar Duke (PD97-1), sampling occurred between 11 January and 13 February. The cruise plan (Table 1) included standard cardinal transect lines (Fig- ure 1), high density sampling within the foraging range of Ade'lie penguins nesting near Palmer Station (Figure 2), periodic visits to the stations near Palmer, and spa- tial variance transects. Three of the five major cruise objectives for 1997 are common to all January cruises: (1) to document interannual variability in various physi- cal and biological variables along and offshore at the mesoscale in the LTER study area; (2) to investigate the linkage between marine resources and Ade'lie penguins dur- ing a time of peak food requirements for the chicks; and (3) to maintain seasonal sampling at the stations near Palmer Station. These nearshore stations are within 3.7 km of Palmer Station and sampled from zodiacs from November through March to document interannual variabil- ity in seasonal patterns (Baker et al., this volume). The fourth objective this year was to document spatial vari- ance of multiple physical and biological parameters on both on/offshore and alongshore transects. The fifth objective was to initiate cooperative studies with the British Antarctic Survey making a visit to Rothera Sta- tion (Figure 1). In addition, the R/V Polar Duke parti- cipated in a broadcast of "Live from Antarctica 2" from Palmer Station in late January. Questions from middle school students were answered real-time by those on board through use of satellite communications. In addition, personnel aboard participated in an xbt study directed by Janet Sprintall of Scripps Institution of Oceanography during the southbound crossing. Standard measurements at stations 20 kilometers apart on cardinal transect lines included: optical and hydrographic characteristics of the water column, gases, microbial parameters, bacterial production, plant pig- ments, primary production, plant physiology, and seabird community composition. Bioacoustic surveys and net tows for zooplankton and krill were centered on each station, and physiological condition determined for krill col- lected. Underway surface measurements between stations included temperature, salinity, fluorescence, seabird community composition, and carbon dioxide partial pres- sure, as measured with a carbon dioxide equilibrator sys- tem. Sea ice was encountered only in the southern part of Grandidier Channel (inside North), the inner reaches of Crystal Sound (inside South), and Tickle Passage (TP) in northern Marguerite Bay. Only one bad weather day was logged, preventing sampling at the two outermost stations on the 500 cardinal transect line. Chlorophyll-a concen- trations were an order of magnitude lower in the northern area of the Peninsula grid in comparison with January 1996. Further, there was less of an onshore to offshore biomass gradient, and phytoplankton communities dominated by Cryptomonads and Prymnesiophytes. In the southern area of the Peninsula grid, biomass was generally less than 1 milligram per meter cubed, although there was a large phytoplankton bloom within Marguerite Bay with sur- face chlorophyll values ranging from 10 to 30 milligram per meter cubed and water column integrated to 30 m values from 2 to 4 milligram per meter cubed that were coincident with low pCO2 values. Diatoms and the Prym- nesiophyte Phaeocystis sp dominated the phytoplankton community. A mixture of salps and krill was found at many stations, with Antarctic krill abundances at average levels. In addition to the mesoscale survey, intensive sam- pling was conducted within the foraging area of Ade'lie penguins whose reproductive success and foraging ecology were being studied simultaneously by investigators at Palmer Station. Surveys were conducted at Torgersen and Humble Islands in conjunction with zodiac tracking of Ade'lie penguins. The relative distributions of the pre- dator (Ade'lie penguins) and prey (Antarctic krill) were observed on high density grids and on 3.7 and 10 kilome- ter picket line transects (Figure 2). Only seabird counts were performed on the picket lines further than 10 kilometers from Palmer Station. The 10 km x 20 km high density grid (Figure 2), as described for 95 January (Quetin et al., 1995), was repeated twice. These seabird censuses showed higher numbers of Ade'lie penguins forag- ing within 10 kilometers of Palmer Station than in previ- ous years, and that most penguins were foraging rela- tively close (< 20 kilometers) to their rookeries where acoustic biomass (primarily Antarctic krill) was higher than further offshore. Annual servicing of the two Palmer LTER program sed- iment trap moorings (Hugo Island and Palmer Basin) and replacement of two Automatic Weather Stations (AWS Bonaparte and AWS Hugo) (Figure 1) were carried out dur- ing cruise PD96-12 in December 1996. However, in early January the R/V Polar Duke visited Hugo Island to com- plete the AWS Hugo service and to survey the island bird population. During the day of exchange with BAS person- nel at Rothera, LTER procedures were discussed (Smith et al., 1997) and demonstrated to those involved with the new British nearshore sampling program. In addition, the diets of Ade'lie penguins on Ginger Island were sampled. The R/V Polar Duke also paid the first official visit of the United States Antarctic Program to the Ukrainian sta- tion, Vernadsky Station. This research cruise was a result of a productive team composed of Palmer LTER research team members with team leaders Karen Carney (B.Fraser/S013), Wendy Kozlowski (M.Vernet/S016), Dave Menzies (R.Smith/S032), Luis Tupas (D.Karl/S046) with special thanks to Charleen Johnson (S032) and Janice Jones (S028/S032) as well as with Antarctic Support Associates personnel and Captain Karl Sanden and his crew of the R/V Polar Duke. Our grateful appreciation is extended to all. This research was supported by National Science Foundation grant OPP- 96-32763. Palmer LTER Contribution No. xxx. References K.S. Baker, W.A. Kozlowski, M.Vernet, J.L. Jones, L.B. Quetin, R.M. Ross, R.C. Smith, and W.R.Fraser, Palmer LTER: Annual Season October 1995-March 1996. Antarctic Journal of the United States (this issue). Live from Antarctica 2. Passport to Knowledge, P.O.Box 1502, Summitt, NJ 07902-1502 (http://quest.arc.nasa.gov/antarctica2). L. Quetin, K.S. Baker, W.R. Fraser, D. Hardesty, J. Jones, R. Ross, R.C. Smith, L. Somervill, W. Trivelpiece, and M. Vernet. 1995. Palmer LTER: Observations in foraging areas of Ade'lie penguins during the January 1995 cruise. Antarctic Journal of the United States 30(5): 269-271. R.C. Smith, L.B. Quetin, R.M. Ross, J. Jones, W.R. Fraser, W.Z. Trivelpiece, L. Somervill, and D. Hardesty. 1995. Palmer LTER: Seabird picket line sampling and zodiac tracking during the January 1995 cruise. Antarc- tic Journal of the United States 30(5): 273-274. R.C. Smith, L.B. Quetin, J.L. Jones, D.W. Menzies, T.A. Newberger. 1996. Palmer LTER: Small Boat Design for Water Column Sampling. Antarctic Journal of the United States (in press). K. Waters and R. C. Smith. 1992. Palmer LTER: A sampling grid for the Palmer LTER program. Antarctic Journal of the United States 27(5):236-239. Figure Legends Figure 1. The cardinal stations of the Palmer LTER regional grid (dots) off the Antarctic Peninsula are overlaid to indicate standard station sampling (large dots) and CTD sampling (circles) during PD97-1. Labeled are Anvers Island (1), Adelaide Island (2), Torgersen Island (T), Palmer Station (o), Rothera Station (R), Ver- nadsky Station (V), Hugo Automatic Weather Station (H; 64o957'S, 65o941'W), sediment trap (triangle), Northern Stations (N; inverted triangle), Southern Stations (S; inverted triangle), Marguerite Bay (M; diamond), Tickle Passage (TP; diamond), and hydrographic parameters only stations (star). The 1000 m bathymetry line (dotted) is shown. Figure 2. Sampling area in the vicinity of Palmer Station on Anvers Island with the Neumeyer (N) and Gerlache Strait to the East. Locations are shown for inshore sta- tion (E) of the Palmer nearshore stations and the Hugo Automatic Weather Station (H). The 3.7 km and 10 km picket lines, the multi picket line (solid line), and the high density grid (HD; dashed line) are shown. The LTER regional grid 600 line stations 040, 060, 080, 100, 120 are marked (filled squares). Table Legend Table 1. LTER 97Jan (PD97-1) Cruise Overview. Daily events summarized include LTER transect lines (grid line), LTER nearshore stations (grid inshore), high den- sity grid (HD), picket lines (PL), zodiac operations, CTD casts, and Automatic Weather Station (AWS). The propor- tion of time spent on each activity during the cruise is summarized.