Glossary

Deutsch: Beifang / Español: Captura incidental / Português: Captura acessória / Français: Capture accessoire / Italiano: Pesca accessoria

Bycatch in the maritime context refers to the unintentional capture of non-target species during commercial or recreational fishing activities. These species can include fish, marine mammals, seabirds, and other marine life that are caught while targeting specific fish species. Bycatch is a significant issue in global fisheries due to its impact on marine ecosystems, sustainability, and conservation efforts.

Description

Bycatch occurs when fishing gear or techniques designed to catch a particular species also capture other organisms that were not intended to be harvested. Common fishing methods associated with high bycatch rates include trawling, longlining, and purse seining. For example, when trawlers drag large nets across the ocean floor or through the water column, they often capture a wide range of species along with the target fish, including endangered species, juvenile fish, or non-commercial species. Similarly, longlines with thousands of baited hooks may attract not only the intended fish, such as tuna or swordfish, but also other marine life like sharks, sea turtles, and seabirds.

The issue of bycatch has ecological, economic, and ethical implications. From an ecological perspective, bycatch can lead to a decline in populations of vulnerable species, disrupt food chains, and damage marine habitats. Economically, bycatch can result in wasted resources, as many non-target species are discarded, often dead or injured, back into the sea. Ethically, concerns arise over the unnecessary suffering and death of countless marine animals.

Efforts to reduce bycatch have become a priority in sustainable fishing practices. Regulatory bodies and environmental organisations promote techniques and technologies designed to minimize bycatch, such as using more selective fishing gear, adopting turtle excluder devices, or implementing real-time closures of fishing areas where high levels of bycatch are expected.

Historically, bycatch has been an overlooked consequence of industrial fishing, particularly in the mid-20th century when fishing technologies advanced rapidly. However, growing awareness of its environmental impact has led to stricter regulations and increased monitoring of fishing activities. In some regions, bycatch reduction is tied to certification programs like the Marine Stewardship Council (MSC), which promotes sustainable fisheries.

Application Areas

Bycatch is an issue in several key areas within the maritime context:

1. Commercial Fishing: Bycatch is most common in large-scale fisheries, particularly those using non-selective methods like bottom trawling or drift nets.
2. Marine Conservation: Efforts to protect endangered species, such as sea turtles, dolphins, and seabirds, are closely tied to reducing bycatch.
3. Regulatory and Policy Making: Governments and international organisations are working to develop policies that limit bycatch, including setting quotas, gear restrictions, and real-time area closures.
4. Aquaculture: While primarily a land-based industry, aquaculture must also manage bycatch in terms of feed sources, especially when wild fish are harvested for fishmeal production.

Well-Known Examples

Bycatch has led to the decline of several species and has brought attention to various conservation issues:

1. Dolphin Bycatch in Tuna Fishing: Historically, dolphin deaths were a major byproduct of tuna purse seine fishing in the Eastern Pacific. International pressure led to the introduction of "dolphin-safe" labels to indicate tuna caught with minimal dolphin bycatch.
2. Sharks in Longline Fisheries: Sharks, especially endangered species, are frequently caught as bycatch in tuna and swordfish longline fisheries, often leading to overfishing of these species.
3. Turtles in Shrimp Trawling: Sea turtles are often caught in shrimp trawl nets. Turtle excluder devices (TEDs) were introduced to help prevent this bycatch and are now mandated in many fisheries.
4. Albatross and Seabirds in Longlining: Seabirds, particularly albatrosses, are commonly caught in longline fisheries. Weighted hooks and bird-scaring lines are now used to mitigate this issue.

Risks and Challenges

Bycatch poses several risks and challenges in the maritime context:

1. Ecosystem Disruption: Bycatch can significantly affect marine biodiversity by removing non-target species that play crucial roles in the ecosystem. This disruption can lead to imbalances, such as the overpopulation of certain species or the decline of predator species.
2. Endangered Species: Many species caught as bycatch are already endangered or vulnerable, exacerbating their population declines. For example, several species of sea turtles, dolphins, and sharks are frequently caught accidentally.
3. Economic Waste: Bycatch often results in the capture of non-commercial species, leading to their discard. In some cases, bycatch can also damage fishing gear, creating additional costs for fishers.
4. Regulation and Enforcement: While there are regulations in place to reduce bycatch, such as the introduction of selective fishing gear, enforcing these rules globally is a challenge. Illegal, unreported, and unregulated (IUU) fishing often ignores bycatch regulations.
5. Data Collection: Accurately measuring bycatch is difficult, as many incidents go unreported or underreported, making it hard for policymakers to implement effective mitigation strategies.

Similar Terms

• Discards: This refers to the portion of a fish catch that is thrown back into the sea, dead or alive. It is often used synonymously with bycatch, although discards specifically refer to the rejected catch.
• Overfishing: The removal of fish species at a rate faster than they can reproduce. Bycatch can exacerbate overfishing by removing juvenile or endangered species.
• Selective Fishing Gear: Equipment designed to target specific species, reducing the likelihood of bycatch.
• Sustainable Fishing: Practices that aim to maintain fish populations at healthy levels and minimise bycatch and environmental damage.

Summary

Bycatch represents one of the most critical challenges in the maritime industry, as it affects both marine biodiversity and the sustainability of global fisheries. Efforts to reduce bycatch, including regulatory measures and technological innovations, are essential for preserving marine ecosystems and ensuring the long-term viability of fisheries. Through improved fishing practices, better management, and global cooperation, the impact of bycatch can be significantly reduced, benefiting both the environment and the fishing industry.

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