Award: OCE-1041570

This project was aimed at furthering our understanding of how to sustainably manage marine fisheries. The primary approach in all of our studies has been a comparative analysis across a wide range of marine ecosystems, and this comparative analysis has provided the major information that contributed to the individual studies described below. A major outcome of our project has been correcting several popular misconceptions about the status of fish stocks and marine ecosystems and how to evaluate them. Use of the mean trophic level of fish catch has been widely touted as a measure of the ecosystem impact of fishing, and was adopted by the Convention on Biodiversity as a measure of ecosystem health. One part of our project showed that there is no relationship between the mean trophic level of the catch and the impact of fishing, and that contrary to previous publications and popular perception, the mean trophic level of global catch has been increasing not declining. A second common conception is that catch data from a fishery can provide a useful indicator of the status of fish stocks. In several publications we showed how this is not true, and that catch data is often misleading. We also developed methods for using catch data and other sources of data to provide information on fish stock status. While it has long been recognized that many fish stocks undergo decadal long changes in productivity unrelated to fishing pressure, we have shown that these "regime shifts" are near ubiquitous in fish stocks, and that management paradigms need to be seriously redesigned to accommodate such changes. We demonstrate that many declines if fish stocks are caused by environmental change, and the scientific challenge is distinguishing between the impacts of fishing and the environmental regime shifts. We have begun a project on evaluating the relationship between the ways that fisheries are managed and the biological, economic and social performance of fisheries. We have compared the management approaches in many different marine ecosystems, and showed how different the performance of fisheries can be. This project is far from complete and is being continued with numerous other sources of funding. Several of the elements of our project examined the tradeoffs between sustainable food production and the environmental impacts of fishing. We have shown that such trade-offs are often unavoidable, but that good science can identify how to minimize the environmental impacts of fishing while still producing food from the sea. Last Modified: 11/01/2014 Submitted by: Ray W Hilborn