Minimize the Risk of Capture
Purse Seine Guidebook
- Table of Contents
- Chapter 1
- Chapter 2
- Chapter 3
- Introduction
- Avoid Bycatch
- Minimize the Risk of Capture
- Reduce Bycatch Mortality
- Offset Unavoidable Bycatch Mortality
- 1. Sharks and Rays
- Sharks and Rays Commonly Encountered
- Reducing Shark and Ray Bycatch
- Target Large Schools
- Attract Sharks Out of the Net
- Fish Sharks in the Net to Release Them
- Modify Fishing Gear
- On Deck Safe Handling and Releasing Techniques
- Manual Handling Do’s
- Handling Medium Sharks
- Handling Stingrays
- Handling and Release with Bycatch Release Devices
- Light Equipment
- Shark Release Ramps with Hopper
- Mobulid Sorting Grids (with Vessel’s Crane)
- Releasing Whale Sharks
- Shark Handling and Release Do’s
- Shark Handling and Release Don’ts
- End Wasteful Shark Finning
- 2. Sea Turtles
- Most Common Bycaught Sea Turtle Species
- 3. Selective Tuna Fishing: Reducing Catch of Small Bigeye & Yellowfin Tuna
- Species Identification
- Yellowfin (30-45 cm)
- Bigeye (30-45cm)
- Yellowfin (46-110cm)
- Bigeye (46-110 cm)
- Yellowfin (>110 cm)
- Bigeye (>110 cm)
- Fisher Cooperation and Input
- Chapter 4
- Introduction
- International Organizations and Instruments
- Inter-American Tropical Tuna Commission
- Western and Central Pacific Fisheries Commission
- International Commission for the Conservation of Atlantic Tunas
- Indian Ocean Tuna Commission
- Commission for the Conservation of Southern Bluefin Tuna
- Further Notes on Data Reporting and Compliance
- Conclusion
- Credits and Citations
2. Minimize the Risk of Capture: During Fishing
If bycatch cannot be completely avoided, the next best step is to reduce the likelihood of catching it during the fishing set.
Techniques include modifying fishing gear or maneuvers to facilitate the escape of non-target species. Examples include the backdown maneuver that allows dolphins to swim out of the net, which could potentially be adapted for other species such as sharks; actively removing and releasing sharks from the net before they reach the deck; attracting sharks out of the net before the final stages of the set; or targeting bigger FAD school sets to reduce shark bycatch.
These techniques have been tested to some extent but require further development. In general, their implementation may interfere with fishing operations, making experimental testing and adoption more challenging.
However, some maneuvers, such as the release of dolphins using the backdown technique, have proven effective and have been in use for many years, which encourages fishers and scientists to continue exploring similar escape options for other vulnerable species, such as sharks.