AUTHORS: Tyler Ham, Missouri Department of Conservation; Shane Bush, Missouri Department of Conservation; Nathan Recktenwald, Missouri Department of Conservation; Christopher Brooke, Missouri Department of Conservation
ABSTRACT: As many reservoirs constructed throughout the USA continue to age, the quality of the fish habitat in these reservoirs has experienced a concomitant decline. Fish and wildlife agencies, nongovernmental organizations, and concerned anglers have all sought to supplement natural fish habitat by installing habitat structures to concentrate fish and improve angler catch rates. In Missouri reservoirs, these structures are primarily composed of submerged cedar, hardwood, or mixed cedar and hardwood trees. Being natural materials, these structures decay over time and require maintenance to provide adequate fish cover. To that end, there exists a paucity of knowledge on the physical longevity of these structures installed in Missouri reservoirs. The objectives of this study were to define the current condition and longevity of fish habitat structures in Missouri reservoirs and to provide management recommendations for the most efficient long-term maintenance and enhancement of habitat structures. Sonar imaging was employed on Table Rock Lake, Bull Shoals Lake, and Harry S. Truman Reservoir in Missouri to generate qualitative categorical condition scores for fish habitat structures. In each reservoir a spectrum of structure types was assessed that represented multiple year classes spanning over a decade. Condition scores were used to further categorize structures based on maintenance needs. We also examined the influence of depth, location, and material on structure longevity. This project focused on evaluating the controllable factors that can improve effectiveness and efficiency of fish habitat projects. Identifying the impact of these factors on fish habitat enhancement projects will have direct application to future decision making and benefit anglers using Missouri reservoirs.
