Hookpod

Hook pod
Image courtesy of Hookpod Ltd

The Hookpod (Hookpod-LED and Hookpod-mini) 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-LED 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 Hookpod mini is a smaller hook-shielding device which operates in the same way as the Hookpod, 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 Hookpod mini weighs 49g and does not include an LED light source. Like the Hookpod, it is also attached to the hook on deployment.

Both the Hookpod-LED and the Hookpod-mini have been assessed by ACAP (2023) 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:

'Hookpod’-LED' – 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.

‘Hookpod-mini’ – 48 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 a stand-alone measure.

Effect on Other Bycatch Species

Research conducted in three different regions showed that the Hookpod did not increase bycatch of other taxa [1]. Trials (in 2019) on commercial vessels off southern Brazil, where Hookpod-minis were deployed to open at 20m depth, did not reduce sea turtle bycatch [7].

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 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%. See the Hookpod website for cost details and FAQ.

Compliance

A combination of port-based inspections and vessel based monitoring and surveillance (e.g. observer inspection of line setting operations; video surveillance; at-sea compliance checks) will be required to assess use and compliance [5]. Once Hookpods are purchased and fitted they are effectively integral to the gear, and this may be verified by visual inspection [1].

Further Research

Further field research to evaluate the relative contributions of the sink rates and hook protection components of hook-shielding devices in reducing seabird bycatch.

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. 2023.ACAP Review and Best Practice Advice for Reducing the Impact of Pelagic Longline Fisheries on Seabirds. Thirteenth Meeting of the Advisory Committee, Edinburg, UK.
  6. Birdlife International, ACAP (2019) Hook Shielding Factsheet. English, Bahasa Indonesian, Japanese, Portuguese, Simplified & Traditional Chinese.
  7. Gianuca D, Canani G, Silva-Costa A, et al (2021) Trialling the new Hookpod-mini, configured to open at 20 m depth, in pelagic longline fisheries off southern Brazil. In: ACAP - Tenth Meeting of the Seabird Bycatch Working Group. ACAP SBWG10 Inf 16, Electronic Meeting.
  8. Swimmer Y, Zollett E, Gutierrez A (2020) Bycatch mitigation of protected and threatened species in tuna purse seine and longline fisheries. Endang Species Res 43:517–542. https://doi.org/10.3354/esr01069