Mean respiration and excretion rates for micronekton from ARSV Laurence M. Gould and RVIB Nathaniel B. Palmer cruises LMG0104, LMG0203, NBP0104, and NBP0204 in the Southern Ocean from 2001-2002 (SOGLOBEC project)

<p><strong>Mean respiration and excretion rates for micronekton Southern Ocean GLOBEC</strong></p>

<p><strong>Collection of specimens.</strong> Crustaceans were collected using either mouth-closing Tucker trawls (9.0 m² or 2.25 m² mouth area) or downward-looking, vertically deployed plummet nets (1 m² mouth area). Tucker trawls were equipped with either blind or thermal-turbulence-protecting cod-ends (Childress et al. 1978); plummet nets terminated in bind cod-ends only. Specimens were taken in the upper 1000m of the water column in the vicinity of the marginal ice zone during spring (November-December) 1983, fall (March) 1986, and winter (June-August) 1988 as part of the AMERIEZ (Antarctic Marine Ecosystem Research at the Ice Edge Zone) program to study ice edge biology. Sampling locations were all in the Scotia-Weddell Sea region but moved with seasonal movement of the pack ice edge. Thus, spring and winter collections were in the Scotia Sea in the vicinity of 60deg S, 40deg W; fall sampling took place further south, 65deg S, 46deg W. Collections were made on a continuum from deep in the pack ice out to 300 km seaward of the ice edge in fall and winter. In spring, collections were made in the open water only. Station locations are given in Donnelly <em>et al.</em> (1990).</p>

<p>Oxygen consumption rates were determined by allowing individuals to deplete the oxygen in a sealed container filled with filtered (0.45 um pore size) seawater. Temperature was maintained at 0.5 C (+/- 0.1 C) using a refrigerated water bath. Oxygen partial pressure (PO₂) was continuously monitored using a Clark polarographic oxygen electrode (Clark 1956) as an individual reduced oxygen levels to low (10 to 20 mm Hg) partial pressures. Electrodes were calibrated using air- and nitrogen-saturated seawater at the experimental temperature. The time required for consumption of oxygen to low levels varied from 12 to 18 h. Streptomycin and Neomycin (each 25 mg 1^-1) were added to the seawater to minimize microbial growth. To control for possible oxygen consumption by microorganishs, an individual was removed after selected runs, its volume was replaced with fresh seawater, and oxygen consumption was again measured for 2 to 4 h. In all cases microbial oxygen consumption was negligibly low.</p>

<p>References:<br />
Torres, Joseph J., <em>et al.</em>, 2007; The physiology of autumn and winter krill (<em>Euphausia superba</em>) in the waters of the Western Antarctic Peninsula Shelf. <em>GLOBEC International Newsletter</em>, <strong>13</strong>:1, 60-62.</p>

<p><strong>Contact:</strong><br />
Jose Torres<br />
College of Marine Science<br />
University of South Florida<br />
140 Seventh Avenue, South<br />
St. Petersburg, FL 33701<br />
<a href=\"mailto:[e-mail]\">[e-mail]</a></p>

<p><strong>南大洋GLOBEC项目微游泳动物（micronekton）的平均呼吸与排泄速率</strong></p>
<p><strong>标本采集</strong>。甲壳类标本采用两种网具采集：一是口部可闭合的塔克拖网（Tucker trawl），网口面积分别为9.0平方米与2.25平方米；二是垂直下放的俯视式坠网（plummet net），网口面积为1平方米。塔克拖网的拖网囊网（cod-end）分为遮光型与防热湍流型两类（Childress等，1978）；坠网仅采用遮光型囊网。标本采集于1983年春季（11-12月）、1986年秋季（3月）与1988年冬季（6-8月）的海冰边缘区附近水深1000米以浅的水层中，相关采样作为AMERIEZ（冰缘区南极海洋生态系统研究，Antarctic Marine Ecosystem Research at the Ice Edge Zone）计划的一部分，旨在研究冰缘生物学。所有采样点均位于斯科舍-威德尔海（Scotia-Weddell Sea）海域，采样位置随浮冰边缘的季节性移动而变动。因此，春季与冬季的采样点位于斯科台海（Scotia Sea）内南纬60°、西经40°附近区域；秋季采样则在更南侧的南纬65°、西经46°区域开展。秋季与冬季的采样覆盖范围从浮冰密集区内部延伸至冰缘外侧300公里海域。春季采样仅在开阔水域进行。具体站位信息详见Donnelly等（1990）的研究。</p>
<p>耗氧速率通过以下方式测定：将单个实验个体置于装有经0.45微米孔径滤膜过滤的海水的密封容器中，使其消耗容器内的溶解氧。实验温度通过恒温水浴箱控制在0.5℃（±0.1℃）。当个体将容器内氧分压降至10~20毫米汞柱的低水平时，采用克拉克极谱式氧电极（Clark polarographic oxygen electrode，Clark，1956）持续监测氧分压（PO₂）。电极在实验温度下，分别用空气饱和与氮气饱和的海水进行校准。氧分压降至低水平所需的时长为12~18小时。向海水中添加链霉素与新霉素（浓度均为25毫克/升）以抑制微生物生长。为排除微生物可能造成的耗氧干扰，在部分实验结束后将实验个体移出，用新鲜海水替换容器内的原海水，随后继续监测2~4小时的耗氧情况。所有实验中，微生物的耗氧量均可忽略不计。</p>
<p><strong>参考文献</strong>：<br />
Torres, Joseph J.等，2007；南极半岛西部陆架海域秋季与冬季磷虾（<em>Euphausia superba</em>）的生理特征。《GLOBEC国际通讯》（GLOBEC International Newsletter），**13**卷第1期，60-62页。</p>
<p><strong>联系方式</strong>：<br />
何塞·托雷斯（Jose Torres）<br />
南佛罗里达大学海洋科学学院<br />
南第七大道140号<br />
圣彼得斯堡，佛罗里达州33701<br />
<a href="mailto:[e-mail]">[e-mail]</a></p>