ABSTRACT
Lakes, rivers and their associated wetlands are prominent features of the northern landscape. This chapter aims to provide an introduction to the literature on inland aquatic ecosystems of the circumpolar Arctic and Subarctic, with emphasis on current research themes in the North American sector. These themes include traditional limnological subjects such as habitat structure, species diversity, and biological production and food web interactions. One of the major advances in aquatic ecology has been the discovery that minute single-cell organisms play a major role at the base of marine and freshwater food webs. Chrysophytes include mixotrophic species that can play an important role in microbial food webs, and like diatoms these species leave identifiable fossil remains in lake sediments that are useful paleolimnological markers. Studies on the bacteria and protozoa of Toolik Lake have begun to build up a picture of the overall microbial food web in lakes of the region of the Arctic.
