Ecological Effects of Catch Share Fisheries Revealed Through a Global Comparative Analysis

Rights-based fisheries management systems, whereby participants are granted a secure, durable and exclusive access to a portion of the annual catch limits, have been widely promoted as a way to align economic incentives with conservation goals.  Here we estimate the response of ecological indicators to catch share implementation via a global meta-analysis of catch share fisheries.  Central to our approach is the development of time series methods that allow us to better identify the changes in indicators that can be attributed to the catch share programs by accounting for confounding time-dependent changes that might result from other management actions.  We find that the largest and most consistent effect of catch share implementation is to dampen interannual variance, particularly for annual landings and exploitation rates.  There were large differences among regions in the magnitude of effects, and some of this variation could be explained by the security / durability of the catch share program and also by whether the program was implemented in a single species or multi species fishery.  We conclude that these variance dampening effects are the primary ecological benefit, and but that the magnitude effect varies depending on other elements of the catch share program.