A review of the terrestrial and freshwater invertebrate fauna of the High Arctic archipelago of Svalbard.

Abstract

The terrestrial and freshwater invertebrates of Svalbard (Spitsbergen) are reviewed. In order to provide as complete an overview of the invertebrate fauna as possible this article is not restricted solely to the Insecta, but includes the phyla Rhizopoda, Rotifera, Tardigrada, Nematoda, Annelida, Crustacea and also the classes Collembola and Arachnids. Population densities and dynamics, as well as physiological responses to the high arctic environment, are discussed. Species diversity is poor on Svalbard by comparison with other arctic regions. It is suggested that this is due to a combination of the extreme isolation of the archipelago, the high Arctic climate and the ecologically young age of the ecosystem. The distribution of the invertebrate species throughout the islands is dependent on factors such as microclimate, vegetation, bed rock and water quality. The majority of the invertebrate species have wide circumpolar distributions and there are few endemics. The four principle methods of dispersal to islands; i) wind currents (and frontal systems), ii) oceanic currents (drift wood etc.), iii) animal vectors and iv) human introductions, are discussed with relation to the current Svalbard fauna. The inhabitation of glacial refugia on Svalbard during the last glaciation is considered.