According to a global review, incidental bycatch in longline fisheries is responsible for at least 160,000 seabird deaths each year (Anderson et al., 2011). Seabirds take baited hooks intended for tuna and swordfish, are gradually dragged under and drown. This mortality is one of the main drivers of population declines in vulnerable seabird species (Croxall et al., 2012) but also represents a problem with very tangible solutions.
The Seabird Bycatch Working Group of the Agreement on the Conservation of Albatrosses and Petrels (ACAP) recommends best practice advice to fisheries where bycatch occurs. Up until May 2016 ACAPs’ advice recommended that longline captains deployed bird-scaring lines, used specific line weighting configurations and set their lines at night to avoid catching seabirds – a combination of three measures. These measures are designed to scare birds away from the dangerous zone where hooks are sinking (bird-scaring line), sink the hooks rapidly away from the birds (line weighting) and deploy hooks under the cover of darkness (night setting). Any two of these three measures used in combination are very effective, and all three measures in combination provide excellent protection for seabirds. However, it has proven difficult to convince captains to use all three measures simultaneously.
Albatrosses are incredible apex predators, but are vulnerable to bycatch in fisheries. (Credit: Augusto Silva-Costa, Projeto Albatroz)
This year, a new option was added to ACAP recommendations that will make it easier for fishers to avoid killing seabirds, whilst still catching fish. The new option is to shield the hooks during deployment until they are out of the reach of foraging seabirds. Two measures were approved by the Working Group; the Hookpod and the Smart Tuna Hook, both of which shield the barb of the hook, essentially de-arming it, while it sinks in the water column. Each has a clever mechanism that releases the hook once it has sunk below the dive depths of vulnerable seabirds.
Incidental bycatch is major driver of albatross population declines. (Credit: John Paterson)
The Hookpod locks the barb of a baited hook within a capsule until a depth of ten metres. At ten metres the ambient pressure is equivalent to double the atmospheric pressure at sea level. This increase in pressure activates a piston, releasing a latch that holds the Hookpod closed. Upon opening, the baited hook is free to fish tuna and swordfish, while the Hookpod hangs on the line ready for use again on the next set. A video is available that shows this process on the Hookpod website (link above).
BirdLife International’s Albatross Task Force has played a role in testing the Hookpod at different stages of development on pelagic longline vessels in Australia, South Africa and Brazil. Those efforts have contributed to results that indicate the Hookpod reduces seabird bycatch by 95% compared to standard gear, without affecting fish catch.
The Hookpod with a hook loaded. (Credit: Oliver Yates)
The compliance conundrum
Fishery observers perform many tasks at sea, producing information on the commercial and non-commercial species caught during fishery operations. They can also report on the adherence (or otherwise) to regulations. From at sea monitoring, we know that too few fisheries are actively adopting the combination of all three measures recommended by ACAP, and often do not adopt even two out of the three resulting in unsustainably high seabird bycatch rates years after regulations have been introduced. This is at least partly due to the reluctance of fishing captains to employ what they consider too many measures simultaneously.
Using technology to generate a sea change in fishing practices
With the newly available technology, the RSPB and BirdLife International are working with our project partner in Brazil, Projeto Albatroz, to seed vessels in the pelagic longline fleet with Hookpods. By doing so, our objective is to create awareness and practical experience of this one stop mitigation measure. Hookpods were trialled in Brazil during several stages of the Hookpod development and were extremely well received by the captains and crew of the vessels.
The initial cost of Hookpods to fishermen will be approximately £10 each but the investment by fishermen will be covered by efficiencies and cost savings. These are: by eliminating the use of light sticks, line weighting, tori lines, night fishing and the loss of baits to seabirds. Hookpods are tough and reliable with an expected life of three years.
The Hookpod in use in Australia. (Credit: Oliver Yates)
To help fund the cost of seeding the Brazilian fleet with Hookpods, we have set up a crowd sourcing project through www.experiment.com through which we hope to raise ~£5,000 toward the purchase of this exciting new mitigation measure and reusable LED lights to replace the disposable plastic light sticks that the fleet uses to attract fish to the hooks. The use of these lights, in combination with the Hookpod could save thousands of albatrosses and petrels each year, and reduce the discard of as many as six million light sticks per year into the marine ecosystem.
About the Author
Oliver Yates is the Programme Manager of BirdLife International’s Albatross Task Force. He holds a BSc in Zoology (Marine and Fisheries Biology) and an MSc in Geographical Information Systems. Oli worked in the Falkland Islands Fishery Department as an at sea observer between 2001 and 2005 before going on to work as Coordinator of the Falklands Albatross and Petrel Programme. From the Falklands, Oli moved with his wife, Paola, to Chile where he took up his current position in 2007. He returned to the UK in 2015 and is now based at the Royal Society for the Protection of Birds (RSPB) in Sandy, Bedfordshire.