Funded
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- Objectives
- Reduce bycatches of small fishes (tunas and others) in purse-seine sets
- Background
- Small individuals of any species (target or non-target) of no market value should be released to reduce the impacts of fishing operations and improve the sustainability of the fishery.
- Many seiners have sorting grids, different types of panels to allow the escape of fish of a size determined by the dimensions of the grid used, but their use has not been well documented because captains can lift them out of the water, and they do so not to lose any potential catches.
- Previous experiments have quantified unwanted species passing through the grid. It is necessary to test their survival after escaping, since they may have been injured while going through the grid.
- Experiments to verify survival should follow the tests of the grid to release unwanted individuals.
- Relevance for management
- Reduce the impacts of fishing and improve the sustainability of the fishery
- Duration
- 18 months
- Workplan and status
- Convene a workshop with fishing captains and gear experts to decide on the standard design for all tests, using previous experience from the region.
- Build the design in 2 seiners, with a commitment to cooperate by leaving the grid fully underwater in all sets.
- Monitor with a camera the utilization of the grid in all sets.
- Deploy a speedboat with a researcher to film escape through the grid.
- This initial pilot program will attempt to measure the quantity and characteristics of escaped fish, not their survival
- Evaluate the significance of the releases, assuming survival.
- If significant, design a project to measure survival in a floating pen.
- Discuss with captains ways to improve their operation if needed.
- Deliverables
- May 2019: progress report for SAC-10
- Updated date: 01 May 2024
- Progress summary for the reporting period
- Upon presenting the report of the 1st Workshop of Sorting Grid (refer to the WSSG-01 Meeting Report) during the 9th Meeting of the Bycatch Working Group, the SAC, in its 14th Meeting (see document SAC-14- 16), recommended to the Commission to continue conducting methodological improvement workshops involving scientific personnel, CPC, industry, captains, and experts to build upon the results of the WSSG01. Additionally, it was suggested that observer programs record the usage (or not) of fish excluder grids by tuna purse seine vessels, along with any relevant complementary information. This data should be made accessible to the scientific staff and the SAC for their analysis and consideration. In response to this request, the staff conducted a survey of 43% of the Class 2-6 EPO purse-seine fleet (n=118) as an initial step. Among the surveyed vessels, 37% had the sorting grid installed. Regarding the immersion levels at which the sorting grid typically operates, observers have provided information from 26 trips. In 42% of trips (n=11) the sorting grid operated at 76-100% submerged, in 19% of trips (n=5) it operated at 51-75% submerged, in 31% (n=8) it operated at 26-50% submerged, and in 8% (n=2) it operated at 1-25% submerged.