pnas.202216891

Introduction

• Many sharks and rays are threatened with extinction.

• Recovery paths remain challenging.

• This study utilized a large-scale "Before–After Control–Impact" approach to document successful recoveries in 9 coastal shark species following the implementation of the US Fishery Management Plan for sharks in the Atlantic Ocean.

• The analysis encompassed the IUCN Red List status of 26 wide-ranging coastal sharks and rays, comparing the Northwest to the Southwest Atlantic.

• Findings indicate that extinction risk increases with fishing pressure but can be mitigated by strong management (National Plan of Action for sharks and rays).

Results and Findings

• Governance and Management: Effective governance and science-based fishing limits prevented population collapse and reduced extinction risk for many species in the Northwestern Atlantic.

• The study highlighted successful fisheries management for 11 coastal sharks in US waters through comparison of population trends using a Bayesian state-space model to assess data before and after regulations were implemented in 1993.

• Fishing pressure varies significantly between regions, impacting extinction risk.

Extinction Risk Indicators

• Fishing Exposure: Areas with higher fishing exposures showed a correlation with increased extinction risks.

• Management Strength: Effective management was indicated by robust National Plans of Action for sharks and rays, which are essential in reducing extinction risk.

Global Context

• Global fish landings are often underestimated with many fisheries unreported.

• Sustainable fisheries management is urgent due to the growth in seafood consumption and associated socioeconomic issues, notably affecting low-capacity regions.

• Conservation efforts have been effective for some marine megafauna but sharks and rays remain largely depleted globally—with oceanic species down by 71% since 1970.

• The IUCN Red List reveals that 51% of coastal sharks and rays are threatened with extinction due largely to overfishing.

Recovery Successes

• While many shark populations are recovering in well-managed fisheries in developed countries, the status in poorer regions remains precarious.

• Recoveries generally stem from robust regulations, law enforcement, and monitoring efforts.

Fishing Management Strategies

• The need for sustainability lessons from successful fisheries management in countries with developed governance.

• Comparative success using proxies such as fisheries subsidies and participation in international treaties as measures of management effectiveness.

• Recommendations include harmonizing strategies across jurisdictions to prevent conservation efforts in one area from being undermined by poor management practices in others.

Conclusion

• Effective governance and fisheries management are pivotal for the recovery of sharks and rays, suggesting a potential for sustainability even for species with slow reproductive rates.

• Collaborative efforts between managers, scientists, and local communities are essential for successful recovery initiatives.

• A holistic approach is recommended for achieving biodiversity goals and ensuring food security through sustainable fisheries management.