Zooplankton Standing Crop in the Pacific Sector of the Antarctic
- George A. Llano and
- I. Eugene Wallen
Published Online: 14 MAR 2013
Copyright © 1971 by the AmericanG eophysical Union.
Biology of the Antarctic Seas IV
How to Cite
Hopkins, T. L. (1971) Zooplankton Standing Crop in the Pacific Sector of the Antarctic, in Biology of the Antarctic Seas IV (eds G. A. Llano and I. E. Wallen), American Geophysical Union, Washington, D. C.. doi: 10.1029/AR017p0347
- Published Online: 14 MAR 2013
- Published Print: 1 JAN 1971
Print ISBN: 9780875901176
Online ISBN: 9781118664551
- Bé closing nets;
- Biomass estimation;
- Herbivore-e trophic relationships;
- Phytoplankton production;
- Phytoplankton-zooplankton trophic relationships;
- Plankton biomass values;
- Zooplankton standing crop;
- Zooplankton trophic relationships
Zooplankton standing crop was estimated in the Pacific sector of the Antarctic between 75°W and 175°W from collections made in 1963 to 1965 on eight cruises of the USNS Eltanin. Samples were taken with 202-μ mesh closing nets to depths of 2000 meters. Copepods, chaetognaths, and euphausiids made up most of the catch, with copepods averaging 67.3%, 68.8%, and 70.1% of the biomass in the antarctic, subantarctic, and convergence zone waters sampled, respectively. The most important contributors to standing crop were Rhincalanus, Calanoides, Calanus, Metridia, Eukrohnia, Thysanoessa, Euchaeta, Sagitta, Euphausia, Oithona, and Pleuromamma. Total biomass in the upper 1000 meters averaged 2.67, 2.58, and 2.96 g dry wt (weight)/m2 in the Antarctic, the Subantarctic, and the convergence zone, respectively.
Seasonal vertical migration noted by other investigators was also evident from Eltanin material. The highest percentages (48–71%) of Zooplankton biomass in the top 250 meters of the 0- to 1000- meter zone were recorded for the spring and summer months of November through January (no February data). In the late fall, winter, and early spring months of May through October, the percentages declined to 4–33%. This seasonal vertical migration pattern was recorded as well for individual species (Rhincalanus gigas, Calanoides acutus, Calanus propinquus, and Metridia gerlachei). Deep closing-net tows to 2000 meters indicate that 27–38% of the biomass of the 0- to 2000-meter layer was in the lower half of the water column from March through October.
Biomass in the Pacific sector of the Antarctic is compared to Zooplankton abundance in other oceanic regions, and phytoplankton-zooplankton and herbivore-carnivore trophic relationships are discussed.