Everyone seems to know that some fish stocks around the world are in trouble, with too much fishing pressure and abundance declining. But there are many success stories with fish stocks increasing in abundance and any overfishing either rare or being reduced. A critical question is why is the status of fish stocks improving in some places and declining in others?
In a recent paper published in Proceedings of the National Academy of Sciences on Dec 19 2016, Mike Melnychuk and 3 co-authors showed that the answer appears to be pretty simple – 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. Three characteristics were particularly important to good outcomes: (1) the scientific assessment of the status of the stock, (2) limiting fishing pressure, and (3) enforcing regulations.
Overall they found that the U.S., Iceland, Norway and Russia had the healthiest fisheries, while the Philippines, Bangladesh, China, Brazil, Thailand and Myanmar had the poorest performing fisheries. This graph shows the scores for each country for 5 different aggregate measures of the management system and the status of the stocks.
The overall score on the management system, which the authors termed a “Fisheries Management Index” (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 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.