Hookpod

Hook pod
Image courtesy of Hookpod Ltd

The Hookpod protects the point and barb of baited hooks from seabird attack during line setting. Branch line weighting at the hook maximises hook sink rate. When a predetermined depth (20m) is reached a pressure release system ensures that the pod opens, releasing the hook to begin fishing. The pod is retrieved during hauling, closed and stored until the next set.

The Hookpod incorporates a light emitting diode (LED) light source that is triggered by a magnetic switch when the device opens at depth. The LED is incorporated as an alternative to disposable chemical light sticks (reducing marine debris) and electric fishing lights.

Experimental research on the efficacy of the hook pod in reducing bycatch of seabirds has been conducted across a range of pelagic fisheries (southern Brazil, South Africa and Australia) over a four-year period, evaluating variables including bait type, hooking position and hook sink rate [1,2]. It has been shown to significantly reduce seabird bycatch without negatively affecting target catch rates [1,3].

The Hook Pod has been assessed by ACAP (May 2019) and included in their list of best practice measures for mitigating seabird bycatch in pelagic longline fisheries [5]. This is conditional upon the device meeting certain performance requirements, noted below:

'Hook Pod’ – 68 g minimum weight that is positioned at the hook, encapsulating the barb and point of the hook during setting, and remains attached until it reaches 10 m in depth, when the hook is released.

ACAP recommends (where regulations allow) that hook-shielding devices can be used as stand-alone measures or with other measures, such as bird-scaring lines and night setting.

The Hookpod mini is a smaller hook-shielding device which has not yet been formally assessed by ACAP, and is therefore not currently on the list of ACAP Best Practice measures. It operates in the same way as the Hook Pod, protecting the baited hooks until they are released at a minimum depth of 10 m. The main differences between the two devices are that the Hook Pod mini weighs 45g and does not include an LED light source. Like the Hook Pod, it is also attached to the hook on deployment.

Effect on Other Bycatch Species

Research conducted in three different regions showed that the Hookpod did not increase bycatch of other taxa. Preliminary findings suggest Hookpods may reduce marine turtle bycatch but further data is needed to validate this [1].

Ease of Deployment and Safety

Hookpods readily fit into standard line storage, setting and hauling operations. There has been ongoing refinement of the ergonomic shape of the pod, to ensure ease of handling, and minimise entanglements with monofilament branchlines during fishing operations [1]. The devices are more easily fitted when the branch line is being built, prior to the hook being crimped onto the branch line, rather than by retro-fitting the device onto existing branch lines [1]. They can be used flexibly with a range of hook sizes and monofilament types and diameters. In addition, they reduce the risk of flyback injury.

Cost Information

The Hookpod replaces branch line weighting using lead weights and/or swivels, with associated cost savings [1]. Details of potential cost savings in fisheries where chemical lightsticks are used can be found in Barrington (2016).

Hookpods are currently priced at £4.95 each (October 2019). However, discounts are available for orders over 2000 units which start at 5% and increase depending on the volume (For example, in NZD: <2000 = NZ$10, >2000 = NZ$9.20, >10,000 NZ$8.50). Bulk orders may be eligible for further negotiation on pricing.

Hookpods have lasted up to 3 years in commercial operations, however the expected life-span is around 2-years. They are manufactured and tested to have a reliability of >99.5%.

Compliance

Monitoring, control and surveillance of the Hookpod technology could be achieved through onboard observer programs, use of electronic monitoring systems that monitor setting operations and in port inspections. Once Hookpods are purchased and fitted they are effectively integral to the gear, and this may be verified by visual inspection [1].

Further Research

The configuration of the Hookpod and Hookpod mini creates a loop of branch line during setting, in which birds could become entangled. It is partly for this reason that the devices need to meet the ACAP line weighting and sink rate requirements. The length of the loop can however be manipulated by changing the point at which the device is attached to the branch line. [5]

References
  1. Barrington, J. 2016. “Hook Pod” as best practice seabird bycatch mitigation in pelagic longline fisheries. In ACAP - Seventh Meeting of the Seabird Bycatch Working Group, La Serena, Chile: ACAP-SBWG7-Doc10.
  2. Sullivan B. J., Kibel B., Kibel P., et al (2017) At‐sea trialling of the Hookpod: a ‘one‐stop’ mitigation solution for seabird bycatch in pelagic longline fisheries. Animal Conservation 21:159–167. doi: 10.1111/acv.12388
  3. Sullivan, B.J., Kibel, P., Kibel, B., Yates, O., Potts, J., and Birdlife Albatross Task Force. 2016. Hook Pod: development and at-sea trialling of a “one-stop” mitigation solution for seabird bycatch in pelagic longline fisheries. In ACAP - Seventh Meeting of the Seabird Bycatch Working Group, Serena, Chile: ACAP-SBWG7-Inf-06.
  4. ACAP. 2017.ACAP Review and Best Practice Advice for Reducing the Impact of Pelagic Longline Fisheries on Seabirds. Tenth Meeting of the Advisory Committee, Wellington.
  5. ACAP. 2019.ACAP Review and Best Practice Advice for Reducing the Impact of Pelagic Longline Fisheries on Seabirds. Eleventh Meeting of the Advisory Committee, Florianópolis, Brazil.