An assessment of stream fish vulnerability and an evaluation of conservation networks in Missouri

Abstract

Stream fish species in Missouri are being exposed to habitat degradation, as well as increases in stream temperature and alterations to the flow regime due to climate change. These threats are likely to have negative consequences on aquatic biodiversity. In order to conserve these species it is important to determine which species are the most vulnerable, and to identify where the best opportunities for conservation and management exist. Two indices to assess stream fish vulnerability were developed and compared. Both indices accounted for species tolerance of habitat degradation, warming stream temperatures, and alterations to the flow regime, as well as factors such as dispersal ability, range size, rarity, and the level of fragmentation of the species habitat. One index used measured species responses to assess environmental tolerances, while the other used trait associations. Species exhibited a range of vulnerabilities, and differences were observed based on whether traits or measured responses were used. A systematic conservation planning tool was used to identify the best areas for stream fish conservation within and complementary to Missouri�s conservation networks. Valuable areas were identified across the state, but the majority of high value stream segments were located in the Ozarks subregion. In addition to providing information to aid in the management and conservation of Missouri�s stream species, these frameworks for assessing stream fish vulnerability and prioritizing stream conservation could be adapted for use in other regions.