Evaluating Largemouth Bass Stocks Following a Golden Algae Kill on the Salt River Reservoirs

Fish kills are a recurring and challenging problem for managing inland fisheries. In 2005, three of the four Salt River Reservoirs located in the Tonto National Forest experienced substantial fish kills related to golden algae blooms. Following these blooms there was a noticeable decrease in largemouth bass (Micropterus salmoides) reported fishing on these lakes. One tool utilized to recover the stock following a sizeable fish kill is stocking. We assess the effectiveness of stocking largemouth bass following the fish kill by modeling the Salt River Reservoir stock dynamics. We reconstructed the largemouth bass populations in each of the Reservoirs and estimated the Ricker stock-recruitment, finally incorporating a general fish-kill into the simulation.  We show that short-term stocking following the fish kill is beneficial if the arrival rate of fish kills is low but with a high golden algae arrival it is not possible to recover the population.  With a low arrival rate after a period of time stocking becomes unnecessary from a biological perspective. Modeling management decisions for recreational fisheries is important to conserve agency resources and make defensible decisions.  Our project services as an example for the value of applying quantitative fisheries techniques to local and regional recreational fisheries.