Nostoc can be found in a variety of environments, both terrestrial and aquatic, depending on the species. Their polysaccharide outer layer and matrix allows them to survive and thrive in a variety of conditions and habits ranging from deserts, semideserts, grasslands, polar, and tropical regions depending on the particular species of Nostoc. In terms of aquatic environments, Nostoc has been documented to be naturally found in marine water, fresh water, as well as brackish water.
