(1 - 2 of 2)
- Temporal changes in marine environments in the Antarctic Peninsula area during the 1994/95 austral summer
- To reveal the temporal changes in Antarctic marine environments during the 1994/95 austral summer, oceanographic surveys were carried out in the Antarctic Peninsula area by Germany, Japan, Korea, and the USA. Five oceanographic stations at 15 nautical mile intervals were selected north of Elephant Island along 55°W; water temperature, salinity, nutrients, phytoplankton, krill and other zooplankton, and acoustic backscatter were sampled by similar sampling protocols. The transect was surveyed six times during the austral summer, from early December 1994 to late February 1995. The major findings from this time-series were : 1) The north/south position of the oceanic frontal zone north of Elephant Island along 55°W varied by 15 nautical miles; the northeasterly current associated with this front, determined by geostrophy, varied in strength depending on position of the front; 2) Most chl-a was concentrated in the upper 50m above or near the pycnocline. Surface chl-a concentrations ranged from 0.5mg/m^3 to >3.5mg/m^3. Peak chl-a (3.62mg/m^3) was found in the surface water during 18 February 1995. 3) Krill spawning during the 1994/95 season was early, extensive and apparently successful compared to previous years; and 4) Taxa other than krill may have contributed substantially to the observed acoustic backscattering.
- Kim, Siegel, Hewitt, Naganobu, Demer, Ichii, Kang, Kawaguchi, Loeb, Amos, Chung, Holm-Hansen, Lee, Silva, Stein
- Variation in the biomass density and demography of Antarctic krill in the vicinity of the South Shetland Islands during the 1999/2000 austral summer,
- Vessels from Japan, Peru, and the USA conducted four sequential surveys designed to estimate the biomass density and demography of Antarctic krill in the vicinity of the South Shetland Islands between late December 1999 and early March 2000. The surveys were conducted during the same austral summer as the CCAMLR 2000 Survey in the Scotia Sea (Watkins et al., Deep-Sea Research, II, this issue [doi: 10.1016/j.dsr2.2004.06.010]), and the data were analyzed in a similar manner. Biomass densities were not significantly different between the surveys and averaged 49 g m -2. Maps of krill biomass indicate three areas of consistently high density: one near the eastern end of Elephant Island, one mid-way between Elephant Island and King George Island, and one near Cape Shirreff on the north side of Livingston Island. The areas of highest krill density appeared to move closer to the shelf break as the season progressed. This apparent movement was accompanied by a change in the demographic structure of the population, with smaller krill absent and a larger proportion of sexually mature animals present in late summer., Cited By (since 1996):8, CODEN: DSROE, Antarctica, ,
- Hewitt, Kim, Naganobu, Gutierrez, Kang, Takao, Quinones, Lee, Shin, Kawaguchi, Emery, Demer, Loeb