A Model to understand population decline of the Devil's Hole Pupfish (Cyprinodon diabolis) and support habitat management decisions

This paper describes a system dynamics simulation model created to help the Devil's Hole Pupfish Recovery Team understand reasons for population decline since the mid-1990s and to evaluate potential interventions to reverse the population decline. After intensive efforts in the 1970s to stabilize the water level in Devil's Hole, the population of the Devil's Hole Pupfish showed slight but steady increase from the 1970s until the mid-1990s. The Team is seeking ways to reverse the recent population decline in the native habitat, but has limited information about the system as well as limited resources for data collection. The focus of this study is the development of a system dynamics model that can help the Team understand the reasons for the population decline, identify critical parameters that should be monitored to anticipate future population changes, and help find habitat management levers that can reverse the population decline.