In Lake Hoare the mats are vertically stratified. Each year one layer is formed and they can be used as indicators of growth and environmental conditions just like tree rings. Similar to microbial mats in other lakes the layers have different pigmentations for light capturing and protection.
Cyanobacterial mats in Lake Hoare
After the divers had brought up mat samples from a depth of ca 10 m, we went back to the lab and identified the diversity using light microscopy. The microbial mats contained different cyanobacteria including the genera Oscillatoria, Phormidium, Leptolyngbya and Nostoc.
After returning to the Natural History Museum, we will carry out DNA-based methods to characterise their evolutionary relationship to other Antarctica cyanobacteria.