Aggregation of algae released from melting sea ice: implications for seeding and sedimentation
Aggregation of algae released from melting sea ice: implications for seeding and sedimentation
复制标题
海冰融化释放的藻类聚集：对播种和沉积的影响
DOI：
10.1007/bf00238457
复制
发表时间：
1991
期刊：
影响因子：
1.7
通讯作者：
V. Smetácek
中科院分区：
文献类型：
--
作者：
U. Riebesell;I. Schloss;I. Schloss;V. Smetácek
在前往威德尔海西北部的R - V北极星巡航（EPOS第2站）期间，研究了影响海冰融化释放的冰藻命运的因素。大尺度浮游植物在后退冰缘的分布格局和小尺度靠近融化浮冰的水柱分布格局均显示出明显的斑块性。典型冰藻对浮游植物的贡献不显著。在模拟海冰融化条件的实验中，冰藻显示出强烈的聚集倾向。从冰内部和入渗层收集的藻类组合在聚集势上存在差异。虽然从冰中收集到的所有藻类都以聚集体的形式存在，但分散藻类和聚集藻类的物种组成存在显著差异。聚集体具有一种独特的结构，由单一的微聚集体组成，这些微聚集体可能是在冰内的微小盐水口袋和通道中形成的。团聚体的沉降速率比分散的冰藻高3个数量级。这些观测结果，再加上本研究中发现的可忽略不计的冰藻播种效应，表明从融化的海冰中释放出来的冰藻受到快速沉积的影响。调查区冰缘的高放牧压力是消除融化过程中释放的冰藻的另一个因素。
SummaryFactors influencing the fate of ice algae released from melting sea ice were studied during a R V Polarstern cruise (EPOS Leg 2) to the northwestern Weddell Sea. The large-scale phytoplankton distribution patterns across the receding ice edge and small-scale profiling of the water column adjacent to melting ice floes indicated marked patchiness on both scales. The contribution of typical ice algae to the phytoplankton was not significant. In experiments simulating the conditions during sea ice melting, ice algae revealed a strong propensity to form aggregates. Differences in the aggregation potential were found for algal assemblages collected from the ice interior and the infiltration layer. Although all algal species collected from the ice were also found in aggregates, the species composition of dispersed and aggregated algae differed significantly. Aggregates were of a characteristic structure consisting of monospecific microaggregates which are likely to have formed in the minute brine pockets and channels within the ice. Sinking rates of aggregates were three orders of magnitude higher than those of dispersed ice algae. These observations, combined with the negligible seeding effect of ice algae found during this study, suggest that ice algae released from the melting sea ice are subject to rapid sedimentation. High grazing pressure at the ice edge of the investigation area is another factor eliminating ice algae released during melting.