Glacial melting and coastal marine microbes of the Arctic

This project focused on the pelagic microbes from the Kongsfjorden-Krossfjorden system located on the West coast of Spitsbergen. The West coast of Spitsbergen is influenced by the West Spitsbergen Current (WSC), which is transformed Atlantic water, characterized by relatively warm and saline water. As a result, the area has overall mild temperatures at a polar site located well above the polar circle. These relatively high temperatures are accelerating the glacial melting at the inner ends of the fjords, providing it with a constant source of freshwater and leading to water column stratification and enhanced water turbidity. This peculiarity of combined warm-saline water inflow, versus an outflow of glacial freshwater has promoted the Kongs-Krossfjorden into a model system for studying climate related changes. We investigated the variability in micro-eukaryotic and bacterial communities by application of culture independent molecular tools, as a function of environmental conditions related with melt water input. This was done during early summer (May-June 2007) and spring (April-May 2008) at various locations in both the Kongsfjorden and Krossfjorden. Parameters included were, for 2007: conductivity, temperature, density, (spectral) irradiance attenuation, nutrients, HPLC pigment fingerprinting, molecular fingerprinting (both 16SrDNA and 18SrDNA), sequencing. In 2008 we additionally measured primary and secondary production, in situ fluorescence and Micro-CARD-Fish.

本研究聚焦于斯匹次卑尔根岛西海岸的Kongsfjorden-Krossfjorden海域浮游微生物。斯匹次卑尔根西海岸受西斯匹次卑尔根海流（West Spitsbergen Current, WSC）影响，该海流携带经过变性的大西洋水，以水温相对偏高、盐度较大为典型特征。因此，这片地处极圈以北的极地海域整体水温相对温和。这类偏高的水温加速了峡湾内端的冰川消融，持续为海域注入淡水，进而引发水体层化并增强水体浊度。这种暖盐水输入与冰川淡水流出的独特水文组合，使Kongs-Krossfjorden成为研究气候相关变化的模式系统。
本研究于2007年初夏（5—6月）与2008年春季（4—5月），在Kongsfjorden与Krossfjorden的多个采样点位开展调查，通过非培养分子生物学技术，解析了与融水输入相关的环境条件驱动下的微真核生物与细菌群落的变异性。
2007年的检测指标包括电导率、水温、密度、（光谱）辐照度衰减率、营养盐、高效液相色谱（HPLC）色素指纹图谱、分子指纹图谱（涵盖16SrDNA与18SrDNA）以及测序分析；2008年则额外增设了初级生产力、次级生产力、原位荧光以及微催化报告沉积荧光原位杂交（Micro-CARD-FISH）的测定。