An auto trawl system is a dynamic system that operates to enhance the performance of trawl gear in varying environmental conditions, such as rough weather or changing seabed topography. A set of sensors attached to the gear feeds back real-time information to a computer onboard, which helps to monitor the trawl as it is towed underwater. Originally designed to improve trawl efficiency, it has since been suggested that auto trawl systems may also be beneficial in mitigating marine mammal bycatch.
Auto trawl systems help to ensure that the entrance of the net remains open during all phases of the trawl, which allows animals that swim into the net (for example dolphins) a chance of escape. This technology can also help to maintain the effective operation of trawl excluder devices and can additionally eliminate any sharp turns and subsequent twisting of the net.
Although further verification is required, the use of auto-trawl systems is suggested as a bycatch mitigation technology to reduce dolphin mortality in trawl nets. During observations in a North-West Australian trawl fishery it was noted that dolphins, once in the net, preferred to seek the known exit at the mouth of the net rather than use the trawl-excluder device exit. Using auto trawl systems improves the stability of towed fishing gear which keeps the net fishing effectively, and could in turn help maintain an “exit” for non-target animals that enter the net.
This page was last updated on 12.02.21.
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