A survey of the riparian Coleoptera fauna along the river Altaelva after 15 years with regulation

Abstract

The riparian Coleoptera fauna of the river Altaelva, Finmark County, Northern Norway, has been surveyed in summer 2002 and 2003. The river Altaelva has been regulated since 1987, and my objective was to investigate the effect of the regulation on the riparian fauna. In total, 37 localities were examined, and four methods were used: hand collecting, washing without area limitation, quadrate sampling with washing and pitfall trapping. In sum, 2949 beetles were sampled, representing 88 species among which 27 were riparian. The majority of the species recorded from before the regulation, were also found in this survey, and their habitat distribution were in accordance with the literature. The species that were not found again are lithophilous. Four species were recorded for the first time in the Alta region. The impact of flood prevention walls and the effects of tributaries are discussed. In addition, the viability of the Cicindela maritima population and the importance of secondary, anthropogenic habitats are also considered. It is recommended that the annual water regime remain unchanged and that building of new flood prevention walls and other constructions are avoided.