Phytoplankton, the primary producers of all aquatic systems, form the base of the marine food web. Any change in the environmental settings of the given ecosystem will affect the phytoplankton community structure of the region. In the present work, water sampling was carried out from the poorly explored polar region, beneath the sea ice during the melting phase of land-fast ice near Indian Antarctic Research Station Bharati in Prydz Bay, East Antarctica. The water samples were analyzed for phytoplankton species diversity, nutrients, temperature, salinity, and Chlorophyll a (Chl a). Our observations indicate marked variations in phytoplankton biomass and community. A shift from diatom (Thalassiosira sp., Fragilariopsis sp.) to dinoflagellate (Protoperidinium sp.) community, along with the emergence of grazers was seen by the end of the observation period. The background environmental conditions also showed marked variations, as the concentration of nitrate at 0m depth reduced from 31.8 μM at Obs-1 to a non-detectable limit at Obs-3. Furthermore, at 0m depth, temperature increased from −1.32 °C at Obs-1 to −0.38 °C at Obs-3 while salinity decreased from 34.11 at Obs-1 to 33.68 at Obs-3, thus indicating the melting phase of sea ice from Obs-1 to Obs-3. These observations showed vertical stratification resulting from the basal melting of land-fast sea ice resulted in better availability of light, phytoplankton community change due to nutrient availability/utilization/limitation, followed by the presence of grazer community. This preliminary understanding will serve as a baseline dataset to design the targeted sampling/experiments in the future from the land-fast ice ecosystem.

浮游植物是所有水生系统的主要生产者，构成海洋食物网的基础。特定生态系统环境设置的任何变化都会影响该地区的浮游植物群落结构。在目前的工作中，水样是在东南极洲普里兹湾印度南极研究站巴拉蒂附近陆地固定冰融化阶段的海冰下方的极地地区进行的。对水样进行浮游植物物种多样性、营养物、温度、盐度和叶绿素a (Chl a ) 分析。我们的观察表明浮游植物生物量和群落存在显着变化。在观察期结束时，发现了从硅藻（Thalassiosira sp.、Fragilariopsis sp.）到甲藻（Protoperidinium sp.）群落的转变，以及食草动物的出现。背景环境条件也显示出明显的变化，0 米深度的硝酸盐浓度从 Obs-1 的 31.8 μM 降低到 Obs-3 的不可检测极限。此外，在0米深度处，温度从Obs-1的-1.32°C上升到Obs-3的-0.38°C，而盐度从Obs-1的34.11下降到Obs-3的33.68，从而表明海冰处于融化阶段从 Obs-1 到 Obs-3。这些观察结果表明，由于固陆海冰底部融化而导致的垂直分层导致了光的更好利用，由于养分的可用性/利用/限制，浮游植物群落发生变化，随后出现了食草动物群落。这一初步了解将作为基线数据集，用于设计未来从陆地固定冰生态系统中进行的有针对性的采样/实验。