Stream and lake fishes are important economic and recreational resources that respond
to alterations in their surrounding watersheds and serve as indicators of ecological
stressors on aquatic ecosystems. Research suggests that fish species diversity is
largely influenced by surface water connectivity, or the lack thereof; however, few
studies consider freshwater connections and their effect on both lake and stream fish
communities across broad spatial extents. We used fish data from 559 lakes and 854
streams from the midwestern-northeastern United States to examine the role of surface
water connectivity on fish species richness and community composition. We found that
although lakes and streams share many species, connectivity had a positive effect
on species richness across lakes and streams and helped explain species composition.
Taking an integrated approach that includes both lake and stream fish communities
and connectivity among freshwaters helps inform scientific understanding of what drives
variation in fish species diversity at broad spatial scales and can help managers
who are faced with planning for state-, regional-, or national-scale monitoring and
restoration.
