Oceanographic profile Zooplankton biomass measurements collected using net in the Antarctic during 1989 (NODC Accession 0000971)

Composition of the metazoan plankton was studied during R.V.
"Dmitry Mendeleev" cruise 43 (February to April, 1989) in the Atlantic
sector of the Southern Ocean. Samples were collected from ten stations
at six locations. Four of the locations were in open oceanic waters along
the 15 degree W longitude. Two others were in the Bransfield Strait and
in inshore waters near Elephant Island. At three locations at 15 degrees
W sampling was conducted twice or thrice. At all stations three different
sampling gears were used to collect different size groups of zooplankton:
series hauls were performed by 200 l water-bottle, mesoplankton net and
macroplankton trawl for depths from 200 m to the surface. The average
biomass of zooplankton in open oceanic waters was 20.55 gm-2 wet weight.
Copepoda Calanoida dominate composing 54.8% of the total plankton,
followed by Euphausiacea (19.8%), Ctenophora (9.7%) and Copepoda
Cyclopoida (7.2%). Biomass of any other taxonomic group was less than
1 gm-2. The relative biomass of Calanoida had a tendency to decrease
southward along 15 degrees W from 86.1 to 68.1% in February and from 81.8
to 23.6% in March-April. The relative biomass of Euphausiacea increased
in the same manner from 2.3 to 17.8% in February and from 3.7 to 41.6% in
March-April. The average biomass of calanoids from February to March-
April decreased from 77.3 to 31.2% and that of euphausiids increased from
6.2 to 33.8%. The contribuiton of copepods and euphausiids to the
production of the plantkon community in the Antarctic is discussed.

本研究针对1989年2月至4月期间，"德米特里·门捷列夫"号（R.V. Dmitry Mendeleev）第43次航次在南大洋大西洋扇区开展的科考作业，对后生浮游动物（metazoan plankton）的群落组成展开分析。研究共设置6个站位区域、10个采样点，其中4个站位位于西经15°沿线的开阔大洋水域，剩余2个站位分别设于布兰斯菲尔德海峡（Bransfield Strait）及象岛（Elephant Island）附近的近岸海域。在西经15°沿线的3个站位区域，分别开展了2次或3次重复采样。所有采样点均采用3类不同采样装置，以分离不同粒径级别的浮游动物：以200升采水器、中型浮游生物网（mesoplankton net）及大型浮游生物拖网（macroplankton trawl）完成从200米水深至表层的分层采样作业。开阔大洋水域的浮游动物平均湿重生物量为20.55克/平方米。哲水蚤目（Copepoda Calanoida）为绝对优势类群，占浮游动物总生物量的54.8%；其后依次为磷虾目（Euphausiacea，19.8%）、栉水母动物门（Ctenophora，9.7%）及剑水蚤目（Copepoda Cyclopoida，7.2%）。其余所有分类类群的生物量均低于1克/平方米。沿西经15°向南极方向推进，哲水蚤目的相对生物占比呈下降趋势：2月份该占比从86.1%降至68.1%，3-4月期间则从81.8%降至23.6%。与之对应，磷虾目的相对生物占比则呈上升趋势：2月份该占比从2.3%升至17.8%，3-4月期间则从3.7%升至41.6%。2月至3-4月期间，哲水蚤类的平均生物占比从77.3%降至31.2%，而磷虾类的平均生物占比则从6.2%升至33.8%。本研究还探讨了桡足类与磷虾类在南极浮游生物群落生产力中的贡献。