Performance of Submerged Cool-Season Annual Crops as a Potential Fish Habitat Enhancement Strategy of Reservoir Mudflats
AdvisorMiranda, Leandro E.
Colvin, Michael E.
Sedimentation and drawdown-induced habitat degradation limits reproduction of structure-associated fishes in flood control reservoirs. Littoral habitat enhancement can be accomplished by planting fast growing crops during winter, when lakebeds are exposed, to provide fish habitat during spring flooding. It remains unclear if species of crops differ in their submerged persistence or habitat quality to fish. I submerged six species of cool-season annual crops in mesocosms and monitored plant architecture over time. Adult plantings of two grasses persisted long enough to potentially be used by juvenile fishes in reservoirs. To assess the habitat quality provided by crops, I evaluated selection by juvenile Bluegills and adult Largemouth Bass in outdoor mesocosms. Bluegills selected Balansa Clover the most and Largemouth Bass selected annual Ryegrass. Results suggest some clovers may provide nursery habitat but degrade rapidly once submerged and dense annual grasses persist well and provide favorable habitat for prey and predator fish.