A Survival Analysis of Global Fish Stocks

Exploitation rates have been significantly reduced in many commercially exploited populations, poising them from recovery, and yet the majority remains below levels associated with maximum sustainable yield. To set realistic expectations for recovery for these stocks and the associated socio-economic costs of rebuilding, an empirical understanding of the drivers, timelines and overall predictability of recovery is needed. We performed a global Bayesian meta-analysis of stock recoveries to investigate the effects of fishing, life history and exploitation history on recovery timelines and the probability of long term depletion. Our results suggest that fishing and life history are expectedly important determinants of time-to-recovery. We further show that adaptations to long term exploitation may accelerate recovery, but we also demonstrate that these effects can delay recovery and increase the risk of recovery failures in cases of prolonged and intense overfishing. Even under scenarios of complete fishery closure our analysis predicts relatively long and uncertain recovery timelines, which not only highlight the costs of overfishing and rebuilding but also call into question the feasibility of mandatory rebuilding timelines.