Investigating the Efficiency of Trawl Fishing Operation with V-Shaped Otter Boards along with Collapsible Crab Traps and Gillnets: evaluation of catch per unit effort, fuel efficiency, and CO2 emission

Abstract

This study evaluated the performance of the V-shaped otter boards during trawl fishing operations. The V-shaped otter boards were designed by the SEAFDEC Training Department in 2018 to improve fuel efficiency, reduce seabed disturbance, and enhance operational safety. The initial sea trials, comparing only the main engine revolution, indicated a 5.4 % reduction in fuel consumption, attributed to a decrease in engine revolutions while maintaining the same trawling ship speed.

Between 2020 and 2023, further experiments were conducted as part of the project “Responsible Fishing Technology and Practices” supported by the Japanese Trust Fund (JTF) 6-2. The experiments were conducted to confirm the benefits of V-shaped otter boards during trawl fishing operations, including improved energy savings and reduced environmental impact. The study involved 14 trawl fishing operations in December 2023 in the Gulf of Thailand using V-shaped otter boards on the M.V. Plalung. Collapsible crab traps and gillnets were also operated during each trawl fishing operation to compare catch quantity, fuel efficiency, and CO₂ emissions.

The results implied that trawl fishing operations with V-shaped otter boards demonstrated significant improvements in catch per unit effort (CPUE) and fuel efficiency over time. However, a negative correlation was observed between trawling duration and catch quantity, suggesting that extended trawling does not necessarily increase catches. Additionally, a positive correlation between trawling duration and fuel consumption was identified, highlighting the adverse environmental impact associated with prolonged fishing operations. The study concludes that while V-shaped otter boards offer the potential for high yields and efficiency; however, careful application is required to balance environmental impacts and operational costs. Future research should include controlled experiments comparing the V-shaped otter boards with traditional designs under identical conditions to validate its effectiveness. Further analysis of hydrodynamic and seabed impacts is recommended to explore the potential advantages of V-shaped otter boards in reducing drag and minimizing environmental disturbance.