Forecasting the Effects of Angler Harvest and Climate Change on Smallmouth Bass Abundance at the Southern Edge of Their Range

Climate change is expected to alter hydrologic regimes and temperatures of stream systems across the United States, affecting stream ecosystems in complex ways. In particular, deviations from historic precipitation and temperature patterns due to climate change will affect lotic fish populations. Smallmouth bass Micropterus dolomieu are ecologically important as top predators in many stream ecosystems and changing environmental conditions could affect population dynamics. However, it is unknown to what extent climate change will affect smallmouth bass at the southern edge of their range, and how angling mortality may interact with climate change induced population alterations. We have created a stage structure population model which incorporates a bioenergetic growth model to examine the relative effects of climate change and angler harvest on the smallmouth bass population in one of the most popular smallmouth bass fisheries in Arkansas, the Buffalo River. We parameterized the model for present, mid-century, and end-of-century climate conditions to compare among time periods. Preliminary results indicate that both climate change and angler harvest can play a critical role in influencing smallmouth bass population dynamics. Managers should take into account the potential effects of climate change on smallmouth bass when considering future regulation changes.