PHYSICAL HABITAT VARIABILITY IN CIBOLO CREEK, TEXAS
Preservation of the full range of physical habitat conditions is an important goal for conserving aquatic diversity in rapidly developing watersheds, such as those around San Antonio, Texas. As a step toward habitat conservation, I quantified physical habitat conditions over a 4 km section of Cibolo Creek, a relatively unimpacted stream in the San Antonio region. I measured width, depth, velocity, substrate, algal cover, organic matter presence, large wood, and canopy cover during baseflow conditions at three points on each of over 300 cross-stream transects. Riffle, pool, run, cascade, backwater, and side channel habitat units were identified visually during measurements. Backwater and side channel habitats, though sometimes isolated from the main channel, had depth and velocity variation within ranges seen in pools and riffles. Deep (>0.5 m) and fast (>0.5 m/s) habitats were rare, making them important targets for habitat management as upstream development expands. Most habitats had similar depth and velocity, indicating that habitat elements such as substrate, large wood, and algal cover may provide important habitat niches. Future work exploring fish habitat selection would provide additional insight into important habitat types to manage as development expands.
Brian Laub (Primary Presenter/Author), The University of Texas at San Antonio, firstname.lastname@example.org;