Improving sustainable practices in tuna purse seine fish aggregating device (FAD) fisheries worldwide through continued collaboration with fishers

Abstract

More than a decade of bottom-up collaborative workshops and research with fishers from the principal tropical tuna purse seine fleets to reduce ecological impacts associated with the use of fish aggregating devices (FADs) has yielded novel improved sustainable fishing practices in all oceans. This integrative effort is founded on participatory knowledge-exchange workshops organized by the International Seafood Sustainability Foundation (ISSF), referred to as “ISSF Skippers Workshops”, where scientists, fishers, and key stakeholders examine and develop together ways and tools to minimize fishery impacts. Workshops organized since 2010 have reached fleet members in 23 countries across Asia, Africa, the Americas, Europe, and Oceania, with over 4,000 attendances, mostly skippers and crew, operating in the Indian, Atlantic, and Pacific oceans. Structured and continued open transparent discussions on ocean-specific options to minimize FAD associated bycatch, ghost fishing and marine pollution have produced an array of novel co-constructed solutions and a better understanding of ecosystem and fishery dynamics. Dedicated at sea research cruises in commercial purse seiners have enabled testing some of the ideas proposed in workshops. Results obtained were then communicated back to fishers for a double loop learning system resulting in solution refinement and/or adoption. Furthermore, fishers’ increased trust and stewardship have stimulated unprecedented large-scale science-industry research projects across oceans, such as multi-fleet biodegradable FAD trials, the adoption and widespread use of non-entangling FADs, and the development and adoption of best practices for the safe handling and release of vulnerable bycatch. This model of collaborative research is broadly applicable to other natural resource conservation fields. Support for long-term inclusive programs enabling harvesters to proactively collaborate in impact mitigation research contributes to improved scientific advice, voluntary compliance, and adaptive management for lasting sustainability trajectories.

Benefits, concerns, and solutions of fishing for tunas with drifting fish aggregation devices

“…Fishers encountering productive dFADs generally replace the original GPS buoy with their own, and the original vessel that constructed and deployed that dFAD loses communications with the buoy or follows the track of the buoy alone, without the dFAD. Moreover, many vessels use tools such as high-tech binoculars, bird radars, helicopters or supply vessels, to actively search and find other vessels' dFADs (Murua et al, 2020) This practice is commonplace worldwide (e.g., between 25% and 50% of the floating object sets by the French fleet in the IO are on objects deployed by other fishing vessel; Wain et al, 2021), with some tuna PS ports having specific zones where appropriated buoys are dropped off and can be recovered by the original owner.…”

“…(a) Underwater view of an old traditional highly entangling dFAD (mesh size above 2.5 cm) currently prohibited by all tRFMOs (© FADIO/IRD/Ifremer/Marc Taquet and zoom in image on the top right from Murua et al, 2017). (b) example of a more recent low entangling dFAD design (mesh size below 2.5 cm) that PS vessels are mandated to use in AO, WCPFC and EPO, in IOTC the use of netting is forbidden and in WCPO will be from 2024 on (© ISSF).…”

Developing indicators to detect the use of fish-aggregating devices

“…Many boats carry materials onboard for one or two aFADs in case they need to repair or replace heavily damaged or lost aFADs (Murua et al 2018) (Fig. 3).…”

Spatio-temporal variability in drifting Fish Aggregating Device (dFAD) beaching events in the Seychelles Archipelago

“…Nevertheless, the two terms should be considered interchangeable in the context of this study. The potential impacts of beachings include the degradation of habitats, disruptions to ecological processes through the introduction of plastics into the food web, and physical damage or mortality to species through entanglement (Macfadyen et al, 2009;Filmalter et al, 2013;Davies et al, 2017;Murua et al, 2017;ISSF, 2019). A recent analysis of dFAD trajectory data estimates that ∼15-20% of dFADs deployed since 2013 by the French fleet in the Indian and Atlantic Ocean eventually beach (Imzilen et al, 2021), whereas discussions with European Union fishers suggest that more than 20% of dFAD deployments likely resulted in beaching events (Moreno et al, 2018).…”

“…There also has been a range of management and scientific efforts to limit the number of dFADs (e.g. IOTC, 2019), to adopt use of non-entangling dFADs (Murua et al, 2017), and develop viable biodegradable dFAD designs (Moreno et al, 2020). Missing from existing work are regional examinations of large datasets of dFAD beachings that assess fine-scale beaching rates and identify highly impacted habitats to inform clean-up strategies.…”