Biological, physical and chemical parameters in water and microbial mat samples from ponds in Victoria Valley

One pond was seen to be different in colour and chemical characteristics and detailed in situ measurements were made of conductivity, temperature and dissolved oxygen at 2cm intervals. Water samples were collected for later chemical analysis. Sediment samples were also collected from the base of three ponds.

Salts were visible in the polygonal frost cracks in the valley floor and a sample of these salts was collected for comparison with the pond salts. Additional samples were collected for biochemistry and biology from sites along the river itself where cyanobacterial mat development was extensive. The following season, the same ponds were sampled in mid-October specifically to collect samples of the highly saline basal brine which occurs below the ice of the predominantly frozen pond over winter.

Temperature, conductivity, pH and dissolved oxygen concentration were measured at various depths. Basal brine and melted ice samples were analysed for major ions and nutrients and trace metals. Ice cores were collected from one pond for analysis of salt content, salt inclusion, ice structure and dissolved gases.