Effectiveness of management regime better predicts fisheries production and sustainability than biodiversity at the EEZ scale

Background/Question/Methods

A common theme in ecology is that biological diversity stabilizes both ecosystem processes and services. Efforts to understand the sustainable use of natural systems, however, typically focus on the effects of different management strategies. In marine ecosystems, the effects of both management and biodiversity on a range of ecosystem services, including fisheries services, have been studied independently; however, their relative effects have not been examined. Our objective was to answer the question: what are the relative effects of ecosystem biodiversity and effectiveness of management regime in predicting fisheries production and sustainability? In this global analysis, we regressed mean and variance of annual landings, stock collapse, and overall fisheries sustainability (measured as biomass divided by biomass at maximum sustainable yield) against biodiversity and management metrics along with geographic area, mean annual primary productivity, and per capita gross domestic product.

Results/Conclusions

We found that at the exclusive economic zone (EEZ) scale, our results support existing theory that both biodiversity and management effectiveness are significant predictors of some fisheries services. Critically, a comparison of biodiversity and management metrics provided strong support that management is more influential in delivering stable fisheries production and sustainability. In particular, total catch and catch variance were most significantly predicted by a single management index derived from principal components analysis. Biodiversity was found not to be a significant predictor of fisheries sustainability measured as B/Bmsy, while the management index tested did significantly predict sustainability (alpha=0.05). These results provide evidence that both extant biodiversity and local management should be considered as key factors in predicting the stability and productivity of marine ecosystem services. Further, a better understanding of what drives the stability of ecosystem services is critical to human health and to improving both our utilization and preservation of the world’s oceans.