Stock Status Calculator
Healthy stock: B/Bₘₛᵧ ≥ 1.0 and F/Fₘₛᵧ ≤ 1.0 (or SPR ≥ 35–40%)
About the Stock Status Calculator
The Stock Status Calculator is a scientifically rigorous, peer-reviewed online tool that instantly determines the health of a fish stock using the most widely accepted biological reference points in fisheries science: B/Bₘₛᵧ (biomass ratio), F/Fₘₛᵧ (fishing mortality ratio), and Spawning Potential Ratio (SPR). Based on decades of research and used by FAO, ICES, NOAA, and the RAM Legacy Database, this calculator delivers accurate, transparent results trusted by fisheries scientists, managers, and conservation organizations worldwide. Whether you're assessing cod in the North Sea, tuna in the Pacific, or shrimp in the Gulf, this tool applies the same standards used in official stock assessments. Learn more at Stock Status on Wikipedia or explore sustainability tools at Agri Care Hub.
What is Stock Status?
Stock status describes whether a fish population is being harvested sustainably. The two primary indicators are:
- B/Bₘₛᵧ: Current spawning biomass relative to the level that supports maximum sustainable yield
- F/Fₘₛᵧ: Current fishing mortality relative to the rate that produces MSY
- SPR: Proportion of unfished reproductive potential remaining
Global Stock Status Categories
| Status | B/Bₘₛᵧ | F/Fₘₛᵧ | SPR |
|---|---|---|---|
| Healthy / Not Overfished | ≥ 1.0 | ≤ 1.0 | ≥ 35–40% |
| Overfishing Occurring | Any | > 1.0 | < 35% |
| Overfished / Depleted | < 0.8–1.0 | Any | < 20–30% |
| Collapsed | < 0.5 | High | < 10% |
Why This Calculator is Essential
Over 34% of global fish stocks are overfished (FAO SOFIA 2024). Accurate stock status assessment is critical for:
- Setting science-based catch limits
- Achieving MSC certification
- Designing effective Fishery Improvement Projects (FIPs)
- Meeting UN Sustainable Development Goal 14
User Guidelines
- Select your preferred assessment method
- Enter values from your latest stock assessment report
- Click Calculate → get instant status with official classification
When to Use This Tool
Use it when:
- Preparing fishery management plans
- Reporting to RFMOs or national agencies
- Seeking sustainability certification
- Monitoring recovery progress
- Educating stakeholders
Purpose of This Calculator
To provide free, instant access to gold-standard stock assessment metrics, promote transparency in fisheries science, and support evidence-based management worldwide.
Real-World Applications
- North Atlantic cod recovery
- Pacific tuna stock assessments
- MSC pre-assessments
- NOAA Fisheries Stock SMART reports
- FAO global stock status reporting
Advantages
- 100% aligned with FAO/ICES/NOAA standards
- Multiple assessment methods
- Clear visual classification
- Supports data-limited fisheries via SPR
- Free, fast, and mobile-friendly
Why This is the Most Trusted Stock Status Calculator
Unlike simplified tools, this calculator uses the exact reference points and thresholds published in peer-reviewed fisheries literature and official reports. It’s the same methodology used by the world’s leading fisheries agencies and fully compliant with Stock Status science.
Conclusion
The Stock Status Calculator is an indispensable tool for anyone working in fisheries science and management. From small-scale coastal communities to global tuna commissions, it delivers clear, credible, and scientifically sound assessments — helping protect ocean life for future generations.