⚠️ Important: All data represents halibut bycatch RATES (pounds per ton of target catch),
not actual tonnage caught. Actual catch amounts are confidential. This analysis covers fishing activity
within the 100 nautical mile Pribilof Islands protection zone only.
⚠️ Observer Coverage Varies: Vessels had different levels of observer coverage and sampled hauls in the Pribilof Zone.
Lower event counts do NOT indicate better performance—they may simply reflect less observation time in the zone.
This data cannot be used to compare vessel performance fairly. All halibut bycatch is problematic regardless of frequency.
Overall Impact Summary
Total Events Analyzed
1,595
Weekly bycatch reports
High-Rate Events
441
≥60 lb/ton (27.6%)
Vessels Tracked
19
Catcher-processors
Peak Rate Recorded
866
lb/ton (Clipper Surprise, 2016)
Worst Years (Most High-Rate Events)
| Rank |
Year |
High-Rate Events |
Average Rate |
Peak Rate |
Severity |
| 1 |
2014 |
109 |
117.8 lb/ton |
752.4 lb/ton |
Extreme |
| 2 |
2013 |
90 |
131.8 lb/ton |
469.6 lb/ton |
Extreme |
| 3 |
2015 |
57 |
122.2 lb/ton |
613.8 lb/ton |
Extreme |
| 4 |
2016 |
57 |
121.6 lb/ton |
866.2 lb/ton |
Extreme |
| 5 |
2024 |
36 |
152.0 lb/ton |
464.4 lb/ton |
High |
Key Findings
- 📍 27.6% of all observed fishing weeks in the Pribilof zone had high bycatch rates (≥60 lb/ton)
- 📅 2013-2014 were the worst consecutive years with 199 combined high-rate events
- 🚢 Top 5 vessels account for 215 (48.8%) of all high-rate events
- 📈 Peak rate of 866.2 lb/ton occurred in 2016 aboard Clipper Surprise
- 🗺️ High-rate events occurred throughout the entire 100nm zone, not concentrated in one area
Data Methodology
This analysis combines two data sources:
- NOAA Observer Data: Weekly halibut bycatch rates from observer reports (CAR 270, 2013-2024)
- AIS Tracking Data: Global Fishing Watch vessel GPS positions matched to bycatch weeks
Each bycatch event shown includes real GPS coordinates averaged from all fishing positions
(speed < 5 knots) during that week within the Pribilof zone. All 1,595 events have been
verified to be within the 100 nautical mile protection zone boundary.