IGN 13-4
Prioritizing fish passage improvement in river networks

Thursday, August 8, 2013
101C, Minneapolis Convention Center
S. Kyle McKay, Environmental Laboratory, U.S. Army Engineer Research and Development Center, Athens, GA
John R. Schramski, College of Engineering, University of Georgia
Jock Conyngham, Environmental Laboratory, U.S. Army Corps of Engineers
Craig Fischenich, Environmental Laboratory, U.S. Army Corps of Engineers
Dams, road crossings, and water diversions disconnect watersheds for fish movement and migration.  The cumulative effect of these structures can be substantial, even when individual barriers have negligible impact.  Rivers may be reconnected through dam removal and other means of fish passage improvement (e.g., fish ladders).  Here, we apply a graph-theoretic method to investigate fish passage connectivity issues.  We use hypothetical watershed configurations to assess general changes to fish passage connectivity with changes in watershed shape (e.g., linear v. highly-dendritic) and the quantity, location, and passability of each barrier.