Ecology and biogeography of freshwater diatoms in ponds of McMurdo Dry Valleys and parts of the Ross Island

TitleEcology and biogeography of freshwater diatoms in ponds of McMurdo Dry Valleys and parts of the Ross Island
Publication TypeThesis
Year of Publication2014
AuthorsSakaeva, A
Secondary AuthorsMcKnight, DM
Academic DepartmentEnvironmental Studies Program
UniversityUniversity of Colorado
CityBoulder, CO
Thesis Typemasters
Keywordsbiological sciences, freshwater diatoms, health and environmental sciences, McMurdo Dry Valleys, ponds

The McMurdo Dry Valleys (MDVs) and the exposed coastal areas of the nearby Ross Island in Antarctica represent some of the coldest, driest places in the world. However, during the austral summer warmer temperatures and constant sunlight allow microbial life to flourish nearly anywhere there is water. Diatoms are single-celled algae encapsulated in a silica shell and diatom communities constitute an important component of the microbial mats that grow in the streams, lakes and ponds in these regions. As part of the Long Term Ecological Research station in the McMurdo Dry Valleys diatom communities have been studied extensively in the streams over the last 20 years. Although the diatoms present in pond microbial mats at Cape Royds have been previously studied, modern-day knowledge of the characteristics of diatom communities in ponds and small lakes throughout the region is limited. This work sought to find the relationships between water chemistry and diatom community structure in ponds. Because water flow is not a factor in ponds and small lakes, influences of salinity, nutrients, pH and other factors can be more easily distinguished. This study looked at 24 separate bodies of water in the Taylor Valley, Labyrinth region in Wright Valley, Cape Royds and McMurdo Station area on Ross Island. The results suggest that geography, dispersal and historical environmental conditions play a significant role in structuring diatom communities, in addition to water chemistry. The results also expand the knowledge of habitat preferences for some of the species present in this region.