Methods
\nZooplankton abundance, vertical and horizontal distribution, and population structure were assessed using a 1 m2 Multiple Opening and Closing Nets and Environmental Sampling System (MOCNESS) with nine nets having 333 \u00b5m mesh and environmental sensors of temperature, salinity and depth. The entire water column was sampled on the downcast using net # 0, which was not analyzed. The upper water column was typically sampled using nets 1 and 2 from 500 m to 200 m at 150 m depth intervals, nets 3 and 4 from 200 m to 100 m at 50 m depth intervals, and nets 5 to 8 from 100 m to the surface at 25 m depth intervals. Some tows were deployed down to 1000 m, and some tows were towed targeting krill swarms at irregular depths. Approximate locations of process study stations are shown in Fig. 1. More precise locations of the casts in Fig. 2.
\nZooplankton samples were immediately preserved in 10% buffered formalin solution. All the large organisms (>15 mm) in the sample were removed and identified to taxa. The sample was then split to about 100 individuals of euphausiids. All euphausiids in the split were identified to species and life history stage and measured for length to the nearest 0.5 mm for larvae and to the nearest 1.0 mm for juvenile and adults. Next the sample was split to about 100 individuals of copepods. Copepods were identified to species and life history stage (female, male, copepodite V, or other copepodite). All other zooplankton in the split were identified to taxa and counted. For the Euchaetidae, we followed the designation of Park (1994) who ascribed the Antarctic species to the genus Paraeuchaeta. This data object (\"krill\") reports the abundance of each euphausiid species by life stage and size class. The companion data object \"zooabund\" reports the counts of zooplankton per subsample/split by taxa and life stage or size class.
\nFurther methodology notes [05/07/08] from K. Daly:
\nMy lab started the net sample analyses and we measured lengths of krill to either the nearest 0.25 mm for larvae or to the nearest 0.5 mm for older stages. As I recall, after we sent splits to the Russians to complete the sample analyses, they decided it took too long to do individual measurements and placed larvae into 0.5 mm length groups (3.0-3.4 mm) and the older stages to the nearest 1.0mm. Jason took his original measurements to 0.25mm and placed them in the 0.5 mm intervals used by the Russians. The 0.5 mm length bins (3.0-3.4; 3.5-3.9;) should be the same for all net tows.
\nFor the epibiont and comment information, the occurrence of epibionts was much higher in 2001. This information is useful as a relative measure of percent occurrence. I have seen these cilates before, but they are episodic.
\nThe comments primarily provide information on indirect development. The larvae were placed into a particular life history stage category, but they don't always have the exact number of telson spines, etc., typical of that stage. I reported this information in my 2004 DSR paper.
\nGreenwich Mean Time was local time + 4 hours.
\n![\"\"](\"http://globec.whoi.edu/images/image002kdaly.gif\")
Fig. 1. Approximate locations of process cruise stations in Marguerite Bay during austral autumn 2001 and 2002.
\n![\"MOCNESS](\"http://globec.whoi.edu/images/MOC_station_map_LMG.png\")
Fig. 2. Locations of MOCNESS stations for LMGould-0104 (2001) and LMGould-0203 (2002) cruises. Numbers correspond to the cast number.
![\"LMG0202](\"http://globec.whoi.edu/images/kdaly_volfilt_info4.png\")