This solution is advanced by:
Entanglement of marine mammals, particularly large whales, remains a significant challenge in fisheries using vertical buoy lines attached to baited traps and other fixed fishing gears. Once entangled, animals may drag gear for long periods, leading to injury or mortality and creating serious conservation and operational concerns.
The MarineGuardian tools to minimise entanglement aim to reduce the severity and consequences of entanglement events by developing fishing gear components that can release marine mammals from vertical buoy lines when interactions occur.
The challenge
Vertical buoy lines used in fixed fishing gears such as pots, longlines and gillnets can pose an entanglement risk to marine mammals moving through fishing areas. These interactions are difficult to prevent entirely and can occur even when mitigation measures are in place.
Reducing harm therefore requires innovative gear-based solutions that can respond when entanglement occurs, while remaining compatible with commercial fishing operations.
The solution
This MarineGuardian solution focuses on the development and testing of time–tension line cutters, a type of device designed to detect and respond to prolonged tension on vertical buoy lines.
This device:
- Detect increased tension over time, equivalent to an entangled marine mammal dragging fishing gear
- Cut the buoy line once a predefined tension threshold and duration are reached
- Separate the entangled animal from the fishing gear, reducing injury and mortality risk
The solution specifically addresses vertical buoy line modifications to reduce entanglement of:
- Marine mammals in pot fisheries targeting snow crab and whelk
- Marine mammals in longline fisheries targeting cod
- Marine mammals in gillnet fisheries targeting Greenland halibut
Development and progress
Development of the vertical buoy line mitigation solution is underway:
- Benchtop experiments have been conducted to document material properties and evaluate variability in device performance
- Field trials are planned for spring 2026 to test the devices under operational fishing conditions
Expected impact
The tools to minimise entanglement with vertical buoy lines are expected to contribute to:
- Reduced injury and mortality of marine mammals due to entanglement
- Improved coexistence between fixed-gear fisheries and marine mammals
- Practical mitigation solutions for deepwater and fixed-gear fisheries
- Progress towards more sustainable fishing practices
