The biomass, productivity and biodiversity of algae in the Cape Hallett region

The distribution and biodiversity of algae was assessed to enable possible future predictions of the effects of global warming. Sites (5 in the first season, 4 in the second) were established around the Cape Hallett peninsula and samples of algae were collected from the ice at regular intervals. As far as possible these sites represented the range of conditions of sea ice in the region. CTD probes measured chlorophyll concentration, temperature and salinity. Algae samples were collected from ice samples, water samples (collected from 5, 25 and 50m depths) and from the sea floor and were used to determine chlorophyll concentration using fluorometry, for carbon and nitrogen concentrations, DNA content, MAA composition, biodiversity and cell numbers (algae and bacteria). PAM and PEA were used to assess photosynthetic capacity of algae extracted from the sea ice. This method was used to determine the response of the algal community to experimentally induced changes in salinity, temperature and light levels. Molecular biological techniques were used to characterise the prokaryotic community in the sea ice and in the water beneath the ice.

为实现对全球变暖影响的未来潜在预测，本研究对藻类的分布与生物多样性展开了评估。研究团队在哈尔特角半岛（Cape Hallett）周边设立了采样站点（第一季设置5个，第二季设置4个），并定期从海冰中采集藻类样本。上述采样站点尽可能覆盖了该区域海冰的各类环境条件。CTD探针（Conductivity-Temperature-Depth Probe）用于测定叶绿素浓度、温度与盐度。藻类样本分别采集自冰样、采集于5米、25米及50米水深的水样以及海底，随后通过荧光光度法测定叶绿素浓度，同时检测碳、氮浓度、DNA含量、类菌孢素氨基酸（MAA）组成、生物多样性以及细胞数量（藻类与细菌）。脉冲振幅调制荧光仪（PAM）与植物效率分析仪（PEA）被用于评估从海冰中提取的藻类的光合能力，并以此探究藻类群落对实验诱导的盐度、温度与光照水平变化的响应。研究人员采用分子生物学技术对海冰及冰下水体中的原核生物群落进行了表征。