Seasonal variation of diel vertical migration of zooplankton from ADCP backscatter time series data in the Lazarev Sea, Antarctica
Seasonal variation of diel vertical migration of zooplankton from ADCP backscatter time series data in the Lazarev Sea, Antarctica
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DOI：
10.1016/j.dsr.2009.10.005
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发表时间：
2010-01-01
影响因子：
2.4
通讯作者：
Kraegefsky, Soeren
中科院分区：
文献类型：
--
作者：
Cisewski, Boris;Strass, Volker H.;Kraegefsky, Soeren
利用2005年2月至12月在格林威治子午线64°5、66.5°5和69°S部署的三台系泊声学多普勒海流剖面仪（ADCPs）获得的10个月平均体积后向散射强度（MVBS）和垂直速度时间序列，分析了拉扎雷夫海浮游动物垂直迁移（DVM）及其季节性和区域变异。估计的MVBS在所有三个系泊点显示出不同的DVM模式。2月至10月，深海浮游动物的停留时间和DVM的时间明显受昼夜节律的支配。连续几个月计算adcp推导的垂直速度的平均日周期，显示最大上升和下降速度分别为16和-15 mm s（-1）。然而，在春末夏初（10月/ 11月），浮游动物群落停止了在三个系泊点的同步垂直迁移，MVBS模式发生了变化。升高的MVBS值集中在66.5°5的最上层（< 50 m）。这一时期与11月初至12月中旬南纬64度和南纬66.5度海冰覆盖率的下降相吻合。在部署结束时测量到的叶绿素浓度升高，从南纬67度扩展到南纬65度，表明浮游植物在50米以上大量繁殖。因此，我们提出，与冰边水华相关的食物供应增加导致浮游动物群落停止DVM以支持进食。2009爱思唯尔有限公司版权所有。
Ten-month time series of mean volume backscattering strength (MVBS) and vertical velocity obtained from three moored acoustic Doppler current profilers (ADCPs) deployed from February until December 2005 at 64 degrees 5, 66.5 degrees 5 and 69 degrees S along the Greenwich Meridian were used to analyse the diel vertical zooplankton migration (DVM) and its seasonality and regional variability in the Lazarev Sea. The estimated MVBS exhibited distinct patterns of DVM at all three mooring sites. Between February and October, the timing of the DVM and the residence time of zooplankton at depth were clearly governed by the day-night rhythm. Mean daily cycles of the ADCP-derived vertical velocity were calculated for successive months and showed maximum ascent and descent velocities of 16 and -15 mm s(-1). However, a change of the MVBS pattern occurred in late spring/early austral summer (October/November), when the zooplankton communities ceased their synchronous vertical migration at all three mooring sites. Elevated MVBS values were then concentrated in the uppermost layers (< 50 m) at 66.5 degrees 5. This period coincided with the decay of sea ice coverage at 64 degrees S and 66.5 degrees S between early November and mid-December. Elevated chlorophyll concentrations, which were measured at the end of the deployment, extended from 67 degrees S to 65 degrees S and indicated a phytoplankton bloom in the upper 50 m. Thus, we propose that the increased food supply associated with an ice edge bloom caused the zooplankton communities to cease their DVM in favour of feeding. (C) 2009 Elsevier Ltd. All rights reserved.