Assessing Habitat Availability in a Hydrodynamic Reservoir System

Habitats may become unavailable to fish in reservoirs at different water elevations. Coves are particularly vulnerable habitat loss, as these peripheral zones isolated from the main reservoir. Quantifying loss elevation reductions and estimating cost of replacing specific types or maintaining a target percentage total cover can help fisheries managers plan for restoration projects reservoirs. We used side-scan sonar estimate areas rock, tree, brush one cove within Harlan County Reservoir, Nebraska, quotes materials, placement, personnel recent replacement maintenance costs. Materials included riprap cedar trees, those needed construct Georgia cubes. Overall, brush, trees covered 2% conservation pool. Rock 10 times more area than 100 trees. All habitats became when decreased by 3.5–4.0 m. The replace each type increased decreased, all 3.5 m was US$390,000. maintain original available (2% area) but only until 2.5 At this point, similar coverage $219,000. Climatic variability lead greater oscillations elevations reservoirs, making vertical distribution even relevant management planning. findings study serve an example how identify costs restorations.