We all know that many fish stocks around the world are in trouble, but also that there are some success stories with fish stocks increasing in abundance and overfishing being reduced. A key question is why is the status of fish stocks improving in some places and declining in others?
Mike Melnychuk and 3 co-authors (Emily Peterson, Matthew Elliott, and Ray Hilborn) made an effort to answer this question in a recent paper.
Their answer is on the logic and simple side: countries that have effective fisheries management systems generally have healthy fish stocks, while those without effective fisheries management have declining abundance and increasing fishing pressure on fish stocks.
In a survey of 28 countries, including the top 20 countries in terms of total landings, they found a good correlation between the management of the fisheries and the state of the fish stocks.
Not surprisingly, three characteristics are particularly important to good outcomes:
(1) the scientific assessment of the status of the stock,
(2) limiting fishing pressure, and
(3) enforcing regulations.
To score on the management system, the authors elaborated a “Fisheries Management Index” (FMI) based on 5 different aggregate measures of the management system and the status of the stocks (Research, Management, Enforcement, Socioeconomics, and Stock status).
I know quite well the fisheries realities of many of the top 14 countries, and the position of some do surprise me... so I search in the methodology and not surprisingly, at least for me, is the absence of a measure for corruption (perhaps via the Transparency Int ranking of the country). But then I agree that is difficult to quantify measure.
In any case (and not surprisingly) the FMI was closely related to the wealth of the countries. Those countries with high per capita GDP had the highest scores in fisheries management.
After accounting for this influence, they further found that fisheries subsidies had considerable impact as well. Investment into the management system (“beneficial subsidies”) produced positive results for the overall management score, as one would hope, but capacity-enhancing subsidies (“bad subsidies”) were associated with poorer overall performance at meeting management objectives.
The FMI, showed wide variation among countries and was strongly affected by per capita gross domestic product (positively) and capacity-enhancing subsidies (negatively). Among 13 management attributes considered, three were particularly influential in whether stock size and fishing mortality are currently in or trending toward desirable states: extensiveness of stock assessments, strength of fishing pressure limits, and comprehensiveness of enforcement programs.
These results support arguments that the key to successful fisheries management is the implementation and enforcement of science based catch or effort limits, and that monetary investment into fisheries can help achieve management objectives if used to limit fishing pressure rather than enhance fishing capacity. Countries with currently less-effective management systems have the greatest potential for improving long-term stock status outcomes and should be the focus of efforts to improve fisheries management globally.
In recent years there has been increasing concern about whether our fisheries can sustainably provide seafood without overfishing fish stocks. Several papers have described the global status of fish populations (i.e., their abundance and exploitation rates) and have hypothesized influences of fisheries management, but this report is unique in being a comprehensive analysis of how specific management attributes (which are numerous and operate simultaneously) affect population status across oceans, countries, and taxonomic groups. This report integrates management policies and population ecology to assess sustainable harvesting outcomes of target species in marine fisheries; results have important global food security implications.
The authors suggest that sustainability of fisheries results from a functioning management system, and the nature of the management system more than the current abundance of fish stocks or the history of catch is a better reflection of sustainability into the future. Improving the performance of global fisheries will be best achieved by improving the fisheries management system in the low-performing countries, especially by building capacity to perform stock assessments, restrict fishing pressure and enforce regulations.