Understanding Bycatch: A Pressing Global Issue

At its core, bycatch refers to the capture of non-target marine animals during fishing operations. This can include anything from undersized fish of a target species to endangered turtles, seabirds, marine mammals, and even deep-sea corals inadvertently snared by trawl nets or longlines. It’s often an unavoidable consequence of non-selective fishing methods, but its scale and impact are a cause for serious concern.

The problem isn’t just about mortality; bycatch can disrupt marine food webs, impact ecosystem health, and undermine the stock recovery efforts for threatened species. For fishing communities, it also represents an economic loss – wasted effort, wasted resources, and potential regulatory restrictions.

The Impact of Bycatch: Why It Matters

The ecological and economic ramifications of bycatch are profound. Globally, it’s estimated that millions of tons of marine life are discarded annually, a staggering waste that affects ocean ecosystems at multiple levels. Addressing bycatch reduction is not just an environmental imperative; it’s also crucial for the long-term viability of fisheries and the livelihoods they support.

Innovative Fishing Gear for Bycatch Reduction

Technological advancements are at the forefront of the fight against bycatch. Engineers and scientists are collaborating with fishers to design and implement smarter, more selective gear that minimizes interaction with non-target species while maintaining efficiency for the intended catch.

Turtle Excluder Devices (TEDs)

Primarily used in shrimp trawl fisheries, TEDs are specialized grids installed in the neck of a trawl net. They are designed to allow shrimp to pass through to the cod end (the collection bag) while guiding larger animals, such as sea turtles and large fish, to an escape opening in the net. TEDs have proven highly effective in reducing turtle bycatch without significantly impacting shrimp catch.

Bycatch Reduction Devices (BRDs)

Similar in concept to TEDs but broader in application, BRDs are modifications to trawl nets designed to allow specific non-target fish to escape. These can include square mesh panels (which are less likely to gill fish than diamond mesh), separator funnels, or specific grids that exploit differences in size and swimming behavior between target and non-target species. Their use is a cornerstone of effective bycatch reduction strategies in many trawl fisheries.

Acoustic Deterrents & Pingers

For gillnet and trawl fisheries, acoustic deterrents (often called ‘pingers’) emit high-frequency sounds that can warn marine mammals, particularly dolphins and porpoises, away from fishing gear. While their effectiveness can vary by species and region, they represent a vital tool in mitigating marine mammal bycatch, aligning with global efforts for responsible fishing.

Circle Hooks and Line Modifications

In longline fisheries, traditional J-hooks often lead to deep hooking of sea turtles, seabirds, and non-target fish. Circle hooks, with their unique design, are much less likely to be swallowed, typically catching animals in the corner of the mouth, making release much safer and increasing survival rates. Other modifications include weighting lines to sink quickly out of seabirds’ reach and using streamer lines (‘tori lines’) to deter birds from baited hooks.

Smart Netting and Camera Systems

Emerging technologies include netting materials that are more visible to marine animals, allowing them to avoid entanglement, and underwater camera systems that provide real-time feedback to fishers, enabling them to make immediate adjustments to avoid concentrations of bycatch species.

Sustainable Fishing Practices & Policies

Beyond gear modifications, changes in fishing practices and robust policy frameworks are critical for comprehensive bycatch reduction.

Time and Area Closures

Temporarily or permanently closing certain fishing grounds, especially during sensitive periods like spawning seasons or when endangered species are known to aggregate, is a highly effective bycatch management tool. These closures protect vulnerable populations and give marine ecosystems space to recover.

Fisher Training and Education

Empowering fishers with the knowledge and skills to use bycatch reduction gear correctly, handle bycatch species gently for release, and understand the ecological context of their work is paramount. Training programs foster a culture of conservation within the industry.

Real-Time Data and Adaptive Management

Monitoring systems, including observer programs and electronic monitoring, provide crucial data on bycatch rates. This real-time information allows fisheries managers to implement adaptive management strategies, quickly adjusting regulations or fishing efforts in response to changing conditions or unexpected bycatch events.

New Zealand’s Commitment to Bycatch Reduction

As a nation deeply connected to its marine environment, New Zealand is actively involved in bycatch reduction efforts. With its unique and often endemic marine wildlife, including Hector’s and Māui dolphins, various seabirds, and diverse fish stocks, New Zealand fisheries continually strive for more sustainable practices. This includes research into innovative gear, implementing species-specific management plans, and fostering collaboration between government, industry, and conservation groups to protect its precious marine heritage.

“New Zealand is committed to reducing the environmental footprint of its fisheries, with a strong focus on protecting marine biodiversity through targeted bycatch reduction initiatives and world-leading research.”

The Future of Bycatch Reduction

The journey towards zero bycatch is complex, but the momentum is undeniable. Future innovations may include advanced sensor technologies for precise fish detection, AI-driven predictive models to avoid bycatch hotspots, and further refinements in gear design that allow for even greater selectivity. Collaboration, ongoing research, and a shared commitment across all stakeholders will be key to achieving truly sustainable fisheries.

Conclusion

Bycatch reduction is a critical endeavor that balances the needs of human consumption with the imperative of marine conservation. Through the ingenious application of innovative fishing gear and the diligent adoption of sustainable practices, we are moving closer to a future where our oceans can thrive, supporting both vibrant marine ecosystems and prosperous fishing communities. Every step towards more selective fishing is a step towards a healthier, more sustainable planet.