Fish movement at the Springbank Dam during open flow conditions: Post-construction monitoring and baseline comparison
fish movement, monitoring, Thames, radio telemetry, white suckers, sucker, bass, upstream, habitat, design
The City of London and the Upper Thames River Conservation Authority originally contracted Biotactic Incorporated in 2006 to design and conduct a study to collect baseline data related to fish movement at the Springbank dam in the spring before stop logs were installed and the dam operated. The baseline data were compared with similar information collected post-construction in 2008 to address Provincial and Federal directives pertaining to the maintenance or enhancement of the status quo related to fish movement at the Springbank dam. Radio-telemetry was used to track the movement of 120 radiotagged white suckers, shorthead redhorse and smallmouth bass (twenty fish of each species, each monitoring year) at the Springbank dam from April 14, 2006 to June 27, 2006 and again from April 19, 2008 to June 15, 2008. All fish were collected from areas upstream from the dam and released downstream after radio-tag implantation. In 2008, fish approached the dam as readily as they did in 2006, but only half as many fish of each species were eventually able pass over the dam gates. Of the two catostomid species (early migrating white suckers and mid season migrating shorthead redhorse) that were monitored; both readily approached the dam, but white sucker took significantly longer to pass through the dam and shorthead redhorse passed through the dam significantly faster in2008. Late spring upstream migrating smallmouth bass took longer to pass through the dam in2008 and some used the structure as habitat. Pre-construction data from 2006, compared with postconstruction data from 2008 indicates that the Springbank dam is not a barrier to fish movement prior to dam closure.