There is already substantial evidence that improving fishery management is the best way to increase ocean sustainability. With a paper published by Zimmerman & Werner last week in Frontiers in Ecology and the Environment, evidence continues to accumulate. Researchers traced the stock health of Northeast Atlantic fisheries from 1960-2015 and found that increases in spawning stock biomass were mainly correlated to fishery policy implementation, though environmental conditions also had an important effect.
The stocks studied in the paper are regulated under the Common Fisheries Policy (CFP) by the European Union. Notably, the CFP underwent a major revision in 2002 that improved management by reducing fishing effort—the major reason stocks have recovered to 1970s level today. Recovery efforts also benefited from favorable environmental conditions (e.g. productivity) at key times—the authors point to 2000 and 2010 as years of high juvenile fish recruitment that significantly helped bring stock levels up.
Three phases in the history of fishing
Zooming out on the history of industrialized fishing would reveal three distinct phases:
- Unregulated fishing for over a century (1800s – 1970s)
- Overfishing resulting from overcapacity fishing fleets as technology, population, economy boom (1970s – 1990s)
- Stock rebuilding and management improvements (2000 – present)
The history of Northeast Atlantic stocks follows that same pattern: take a look at Figure 3 from Zimmerman & Werner 2019 that plots stock biomass (black), catches (red), and recruitment (blue) from 1960-2015:
You might recognize the three distinct phases. As noted by the authors:
The combined trends of catches and SSB reflected the three major historical phases in Northeast Atlantic fisheries: (quasi‐)unregulated fishing activities before 1980, overcapitalized fleets and increasingly severe overfishing between 1980 and 2000, and widespread establishment of stock rebuilding and management plans after 2000
Ray Hilborn wrote a two-part series on Northeast Atlantic fisheries for this site (part 1, part 2). He goes into further detail about individual stocks, but also discusses the potential of Northeast Atlantic fisheries with further management improvements.
Zimmerman & Werner 2019 also points to further management improvement and potential, but warns of climate change and other environmental factors that could have significant impact. Science and management need to be in-sync (and well-funded!) to continue building sustainability in the Northeast Atlantic.
Max Mossler
Max is the managing editor at Sustainable Fisheries UW.
2 Responses
I don’t see an impact of these changes in SSB on recruitment. That seems to imply that recruitment overfishing was not the issue. All that would be required is reasonable limits on fishing to reduce growth overfishing. Am I missing something?
Well, on re-examination, there does seem to be some decline in recruitment over the period, so I’ll take that back. It would be easier to tell if I could analyze the data. However, assuming there is some decline in recruitment, it is not nearly as great as the decline in SSB, which seems to imply that with decent survival of recruits, the SSB could recover. If natural mortality has not increased, then controlling fishing should enable SSB to rebuild.