This description relies upon:
Birdlife International. 2014. Bycatch Mitigation Fact-sheet 12 (September 2014), Demersal and Pelagic Longline: Haul mitigation.
Some vessels have experimented with water cannons or fire hoses to deter birds from approaching the hauling station. Using 30 kw electric centrifugal pump, Kiyota et al. (2001) experimented with various nozzle tips, flow stabilisers and angles of attack to determine the maximum range of the water jet. Under ideal conditions, the maximum distance attained was 60 m and considerably less in crosswinds. This falls considerably below the recommended aerial extent of a streamer line.
Effect on Other Bycatch Species
Ease of Deployment and Safety
Under contrary wind conditions, the water jet can be blown back towards the ship soaking the fishermen on deck.
Although water cannons are not suitable to replace streamer lines in longline fisheries, due to insufficient range, there is possibly potential for use in trawl fisheries, where streamer lines are considerably shorter.
- Birdlife International. 2014. Bycatch Mitigation Fact-sheet 12 (September 2014), Demersal and Pelagic Longline: Haul mitigation.
- Kiyota, M., Minami, H. and Takahashi, M. 2001. Development and tests of water jet devices to avoid incidental take of seabirds in tuna longline fishery. CCSBT ERS-0111-63.