Understanding microalgal composition and contributions in Antarctic glacial meltwater through rbcL sequencing
Year: 2016
Type: dissertation
Abstract: Microbial mats are found globally in dynamic aquatic environments. Visually different \nmorphotypes (orange-red and black-green) also show different rates of nitrogen fixation \nand biogeochemical activity. Glacial meltwater communities in the McMurdo Dry Valleys \n(MDV) of Antarctica present unique opportunities to study microbial mats, due to limited \ngrazing effects and their sensitivity to climate change. Microscopy has yielded a poor \nunderstanding of species composition and diversity. I sought to address this limited \nunderstanding through deep sequencing of photosynthetic genes such as cbbL, and the 16S \nrRNA V4 hypervariable region. A total of 15 transects from five valleys were used, with \nsamples representing stream-associated (submerged) or transiently wetted (hyporheic) \ntransect points. While stream position is a clear driver of mat morphotype, morphotype was \nnot associated with microbial community composition. Microbial mat communities exhibit \ntemporal shifts in relative abundance, but not diversity of microorganisms present. We \npropose that unique mat morphotypes are not distinct communities, but rather a \ncontinuum of the same overall community ranging from submerged to hyporheic habitats. \nAs such, microalgal mats have the potential for morphotypic and biogeochemical functional \nplasticity with changing hydrogeological conditions.
Author: Kathryn Megan Barretto
Language: English
Topic: Polar Research and Ecology
Subfield: Ecology
Field: Environmental Science
Domain: Physical Sciences
SDG: Climate action
Open Access status: green
OpenAlex ID: W2597076024