As part of the Long Term Ecological Research (LTER) project in the McMurdo Dry Valleys of Antarctica, a systematic sampling program has been undertaken to monitor the production of algal mats in glacial meltwater streams of the region. This table contains data showing the chlorophyll, carbon, nitrogen, and hydrogen concentrations of algal communities and some mosses from selected streams from each of three Taylor Valley basins. The data set constitutes the LTER algal and moss biomass data, along with measurements of the amount of carbon and nitrogen associated with algal mats for construction of nutrient budgets