Biology report for the week of 16/7/00 - HMP 2000 During most of the week the biology work was focused on Lake Trinity. Because of the large media influx, much of the time has been spent showing them around the camp and discussing our scientific objectives. During the week ultraviolet radiation data was collected from in and around Lake Trinity, which will be related to the ultraviolet environment of micro-organisms growing in the lake. Part of the effort of the biology program is directed at understanding the responses of organisms to stressors such as UV radiation that are relevant to extreme polar environments and Mars. We can do this by examining in detail the composition of microbial communities in the lakes, including the microbial mats that inhabit the shows regions of lakes. Collections were also made of plants and microbes for the DNA sequencing effort and samples were taken from lakes in the local area for diatom studies. All of these efforts help us to characterize the biology of the crater. Patrick Van Hove left us on Friday for Quebec. He successfully completed the lake sampling work he needed to perform during the time that he was here. The day before he left he travelled to Comet Lake to gather data on profiles of temperature through the lake. His samples will be used to study the cyanobacteria that inhabit the lake waters. Work continues on aspects of the lake and lithic environments of the crater. Next week we are joined by Dale Stokes from Scripps who will bring an instrument that allows us to build 3-D maps of the lakes using sonar.