The Collins glacier is located in the northern part of the Fildes Peninsula. A typical sub-Antarctic ecosphere affected by climate change has been developed near the Collins glacier. However, there are very limited data on the characteristics of bacterial communities in the aquatic ecosystems of the Fildes Peninsula, Antarctica. 

Bacteria are critical for maintaining polar aquatic ecosystem function, and their community composition, indicator species and potential ecological functions can be used to predict changes in aquatic ecosystems.  

In a study published in Ecological Indicators, the research groups led by Prof. BI Yonghong from the Institute of Hydrobiology (IHB) of the Chinese Academy of Sciences and Prof. LUO Wei from the Polar Research Institute of China revealed the differences and hidden linkages between periglacial lakes and coves near the Collins glacier under summer glacier meltwater injection and glacier retreat from the perspective of bacterial communities. 

The researchers analyzed the bacterioplankton and environmental data of five periglacial lakes and two coves in summer obtained from the Great Wall Station of China's 34th, 35th and 36th Antarctic expeditions. They comprehensively explored the diversity, indicator species, and co-occurrence networks of the bacterial communities, and revealed the differences and hidden linkages between these two aquatic habitats. 

The researchers found that Proteobacteria, Cyanobacteria, and Bacteroidota were dominant in the bacterial communities of two distinct but associated aquatic habitats. Although they recruited some unique OTUs, two habitats shared noteworthy proportion of OTUs. Periglacial lakes had higher α diversity, and the β diversity was mainly caused by turnover. 

Based on the indicator species and functional prediction analyses, the researchers found that indicator species identified in coves, such as Polaribacter and Sulfitobacter, were predicted to be more involved in S cycle. Co-occurrence networks showed differences with the periglacial lakes network being more complex and stable. 

These findings confirmed that bacterial communities were mainly shaped by ecological niches, and that although the two aquatic habitats are somehow related and had similar influencing factors, each possessed specific indicator species, diversity and co-occurrence networks.  

This study deepens our understanding of bacterial community characteristics in the two typical aquatic habitats near the Collins glacier, and provides new insights into the impact of glacier retreat on downstream ecosystems.