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4.8 Distribution of skipjack (left) and yellowfin (right) tuna catch by set type, 2013-2019 (Blue-Unassociated; Yellow-Log; Red-Drifting FAD; Green-Anchored FAD).

4.8 Distribution of skipjack (left) and yellowfin (right) tuna catch by set type, 2013-2019 (Blue-Unassociated; Yellow-Log; Red-Drifting FAD; Green-Anchored FAD).

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Conference Paper
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Provides a description of the major tuna fisheries in the WCPFC Statistical Area highlighting activities during the most recent calendar year (2019) and covering the most recent summary of catch estimates by gear and species, including economic conditions.

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... The Pacific Ocean is the world's largest tuna fishing ground, providing more than 55% of the global tuna catch [27]. The study area covers most of the tuna longline fishing grounds (30°S-25°N and 150°E-100°W), as shown in Figure 1, including both tropical and temperate waters. ...
Article
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The pelagic stingray (Pteroplatytrygon violacea), perhaps the only stingray to inhabit open ocean waters, is highly interactive with longline and purse seine fisheries. The threat to P. violacea posed by high bycatch mortality has received widespread attention. To date, the environmental preference of P. violacea, which is important in designing conservation and management measures, has not been well studied. Based on data collected during a 2016–2019 survey in the Pacific Ocean by national observers of tuna longline fisheries, the relationship between the presence of P. violacea and spatiotemporal and environmental variables was first analyzed using the Generalized Additive Model. The results showed that geographic location (latitude and longitude) was the most influential variable. Monthly, P. violacea is frequently present in the Pacific high sea from December to May. The El Niño–Southern Oscillation had a significant impact on the presence of P. violacea in the Pacific high sea, with both the cold (Ocean Nino Index <−0.5) and warm (Ocean Nino Index >1) phases leading to a decrease in its presence. Regarding the environmental factors, we found that high presence was associated with low salinity (33.0~34.5 psu), a relatively high concentration of chlorophyll (0.2–0.35 mg/m3), and warm water (>20 °C). P. violacea was most likely observed in the waters offshore, closer to seamounts, and with water depths between 4000 and 5000 m. Four areas, including those east of the Solomon Islands and east of Kiribati, areas west of the Galapagos Islands, and areas near the coastal upwelling of northern Peru, related to upwelling systems or seamounts, were identified as the potential key habitats of P. violacea. Predicted distribution maps showed a significant seasonal variation in the presence of P. violacea. Moreover, the yearly change in the presence of P. violacea in the Pacific high sea indicated a possible decreasing trend in recent years. The information first provided here is essential for developing conservation and management measures for P. violacea to prevent the unavoidable ecological consequences of bycatch or other anthropogenic factors.
... 8 As new threats and stressors emerge alongside accelerating global environmental and socioeconomic change, 9 calls for increased coordination, cooperation, and transparency across the sector have intensified, and the need for equitable and comprehensive ecosystem-based resource management has grown increasingly urgent. 10,11 Although high-volume purse-seine fisheries comprise the vast majority of large pelagic fisheries landings across the Pacific, pelagic longline fisheries represent a substantial proportion of total catch value (30% in the Western Pacific in 2019 12 ) while exerting significant top-down pressure on open-ocean ecosystems across the basin. 13 Despite its economic and ecological importance, the pelagic longline sector remains poorly understood and difficult to manage because of inadequate information concerning catch and bycatch, fishing effort, and vessel distribution 14,15 and the diverse and (at times) competing priorities of participating nations (Box 1). ...
... In the Western Pacific Ocean (WPO), total longline vessel numbers have slowly declined over the past 15 years from a peak of more than 5,000 vessels in the early 1990s to an estimated 1,672 active fishing vessels operating in 2019. 12 Historical time-series data for Eastern Pacific Ocean (EPO) vessel participation are not available. During the same time, total fishing effort has increased across the Pacific Ocean from 550 million hooks in 1995 to 850 million hooks in 2019 (down from a peak of 950 million hooks in 2012; Figure S1). ...
... Some operate out of ports in Taiwan, but many others are based in Micronesia, Guam, and the Philippines. 12 A majority of these small vessels (61.5 ± 26.9 GRTs) make short (i.e., 7-10 days) trips to target yellowfin and/ or bigeye tuna for fresh sashimi markets, 6,58 consistent with their high overlap with these species ( Figure 5A). Some vessels from this fleet may also engage in the seasonal harvest of ''other'' species, like Pacific bluefin tuna (T. ...
Article
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Ensuring the long-term sustainability of tuna, billfish, and other transboundary fisheries resources begins with data on the status of stocks, as well as information concerning who catches what fish, when, where, and how. Despite recent improvements in fisheries monitoring and surveillance, such dynamics remain poorly understood across the high seas. Here we delineate and describe pelagic longline activity in the Pacific Ocean using a framework that integrates descriptive vessel information and tracking data with species-specific catch reports. When parsed by distinct vessel behaviors and attributes, disaggregated fisheries data highlight the existence of multi-national, multi-specific (i.e., targeting multiple species) fishing fleets, many of which target waters that span more than one management area. Our findings emphasize the need for increased coordination across regional and sub-regional governance bodies and suggest that effective and equitable management of the sector may require efforts to move beyond single-species, single-area controls and operational distinctions based primarily on vessel flag and/or gear type alone.
... Western and Central Pacific (WCP) tuna fisheries form part of much larger social and ecological system (SES). These fisheries contribute just over half of the world's tuna supply while also supporting Pacific island countries' economies (Williams & Ruaia 2020), food security (Pilling et al. 2015), and sovereignty (Hanich et al. 2010). Developing policies that consider these broader SES and their complex interaction is important. ...
Article
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Western and Central Pacific (WCP) tuna fisheries form part of a broad and complex social and ecological system (SES). This consists of interconnected elements including people (social, cultural, economic) and the biophysical environment in which they live. One area that has received little attention by policy makers is gender. Gender is important because it deepens understandings of behaviours, roles, power relations, policies, programs, and services that may differentially impact on social, ecological, economic, cultural, and political realities of people. This paper contributes a “first step” to examining gender issues in WCP tuna SES. Women’s roles in WCP tuna SES in Fiji are explored and an evaluation of the impact fisheries development policy has on gender equality over the past two decades is revealed. Three key findings emerged from interviews, focus group discussions, and observations: 1) traditional gendered roles remain where women are marginalised in either invisible or low-paid and unskilled roles, and violence is sanctioned; 2) gender mainstreaming of policy and practice remain simplistic and narrow, but are transitioning towards more equitable outcomes for women; and 3) failure to consider gender within the context of WCP tuna SES leads to unintended outcomes that undermine potential benefits of the fishery to broader society, especially to women. A multifaceted approach is recommended to integrate substantive gender equality into SES-based approaches. This research argues educating and getting women opportunities to work on boats falls short of redressing inequality and injustice that is embedded in the social, political, and economic status quo.
... bycatch impacts focussed on single species such as sharks (Hutchinson & Bigelow, 2019)); and economics (e.g. prices, catch value, and economic conditions siloed for each fishery and species (Williams & Ruaia, 2020)). ...
... Total WCP tuna catch for 2019 was estimated at 2.9 million metric tonnes, the highest on record. Of this, 2.0 million metric tonnes were skipjack, also a record for the fishery (Post & Squires, 2020;Williams & Ruaia, 2020;Yeeting et al., 2018). For these fisheries, the full picture of the SES network is unknown. ...
... Priority challenges the WCPFC faces in meeting its objectives of long-term conservation and sustainable use of highly migratory species include management of the high seas and setting sustainable limits of commercially harvested tuna species (Azmi & Hanich, 2021;Crothers & Nelson, 2006;Western and Central Pacific Fisheries Commission, 2020b). For example, while the four main commercially harvested tuna stocks are considered "healthy", Pacific Bluefin tuna stocks are designated endangered (Wakamatsu & Managi, 2019) and some fisheries are considered economically unsustainable (Williams & Ruaia, 2020). This is the case for the southern longline fishery's where economic returns have declined (Skirtun et al., 2019). ...
Thesis
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This thesis responds to the need to re-conceptualise the way in which oceans and the SESs they support are understood and governed. Contrary to traditional fisheries management frameworks, this thesis focusses on developing and testing an integrated transdisciplinary framework to examine SES networks. Western and Central Pacific (WCP) tuna fisheries are faced with complex and interlinked social and ecological challenges including high seas management issues, setting sustainable limits, climate change impacts, human rights violations, and illegal, unreported, and unregulated activities. At odds with this complexity, strong but narrow disciplinary fisheries science-based decisions dominate governance decisions. Effective governance across complex multi-scale systems in the WCP tuna fishery requires a more integrated understanding of social-ecological systems (SES). Transdisciplinary problem solving informed by participatory, SES research, and political ecology has the potential to reveal (and solve) complicated interactions and connections across ocean SES networks. A Social-Ecological-Oceans Systems Framework (SECO) was developed to capture the complexity, breadth and depth of the system and address interactions and connections between separate system components. The overarching research hypothesis for my thesis is that a transdisciplinary approach using political ecology and SES research can be used to assemble diverse theories, knowledges, methods, and analytical techniques. Such an approach can reveal and make sense of complicated interactions and connections across ocean SES networks. The hypothesis is tested using SECO in two place-specific studies; undertaken in Fiji and Solomon Islands, both of which are classified as Small Island Developing States. Place-specific studies are good for exploring interlinkages and complex causality in a 'real life' context. I argue that establishing fisheries management systems that are appropriately embedded into SES networks is critical to avoiding unintended outcomes. My research discovers drivers, key interlinkages, and systemic causes of unintended outcomes of tuna fisheries development and governance. Moreover, findings confirm Pacific-led grassroots multi-scalar governance is key to overcoming systemic barriers and taking hold of opportunities to achieving multiple societal goals. Future research could leverage the SECO contribution within the WCP tuna SES or other ocean SES networks.
... Gender norms and the other categories used to discriminate among people intersect in WCPO tuna value chains. (Williams & Ruaia, 2020). The other tuna species relevant to this study are albacore (Thunnus alalunga, Scombridae) and the coastal neritic tunas longtail (Thunnus tonggol, Scombridae), frigate tuna (Auxis thazard, Scombridae) and bullet tuna (Auxis rochei, Scombridae). ...
Article
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The USD6 billion Western and Central Pacific Ocean (WCPO) tuna fisheries produce over half the world's tuna and are important for coastal countries. Tuna fisheries policy, management and research currently focus on fisheries resources and industrial fishing on offshore vessels with all male crews, although women, as much as men, are employed in tuna processing and trading in domestic, informal and export value chains. We apply a gender lens to four WCPO case‐study tuna industries: Suva and Levuka in Fiji, Bitung in Indonesia, General Santos City in the Philippines and Western Province including Noro in Solomon Islands. The gender divisions of labour, livelihood opportunities and social impacts vary greatly across the value chain nodes, depending on the size, quantity and quality of fish handled, and the scale of operations. The gender lens also reveals the social impacts of fishing when husbands/fathers/sons are killed or injured, absent for long periods and engage in sex, drugs and alcohol behaviours in port. Despite the centrality of women in tuna industries, and the gendered social impacts, regional and national policies largely omit gender. The tuna discourse should be broadened from that of male‐dominated industrial fishing to whole of value chains including domestic and informal enterprises in which women are equally involved. Progress on gender equity needs collaboration by multiple stakeholders including industrial firms employing people in factories, offices and on fishing vessels, regional bodies and national governments responsible for policy, monitoring and regulation, and research agencies to build knowledge.
... bycatch impacts focussed on single species such as sharks [47]); and economics (e.g. prices, catch value, and economic conditions siloed for each fishery and species [95]). Furthermore, like many other fisheries, the WCP tuna fishery has moved towards market friendly institutions, policies, and investment [69]. ...
... Total WCP tuna catch for 2019 was estimated at 2.9 million metric tonnes, the highest on record. Of this, 2.0 million metric tonnes was skipjack, also a record for the fishery [71,95,97]. For these fisheries, the full picture of the SES network is unknown. ...
... Priority challenges the WCPFC faces in meeting its objectives of long-term conservation and sustainable use of highly migratory species include management of the high seas and setting sustainable limits of commercially harvested tuna species [8,22,92]. For example, while the four main commercially harvested tuna stocks are considered "healthy", Pacific Bluefin tuna stocks are designated endangered [88] and some fisheries are considered economically unsustainable [95]. This is the case for the southern longline fishery's where economic returns have declined [78]. ...
Article
Western and Central Pacific (WCP) tuna fisheries are faced with complex and interlinked social and ecological challenges including high seas management issues, setting sustainable limits, human rights violations, and illegal, unreported, and unregulated (IUU) activities. However, strong but narrow disciplinary science persist to dominate governance. Effective governance across complex multi-scale systems in the WCP tuna fishery requires a more integrated understanding of social-ecological systems (SES). Transdisciplinary problem solving informed by participatory, social-ecological resilience research, and political ecology has the potential to reveal complicated interactions and connections across ocean SES networks. Social-Ecological-Oceans Systems Framework (SECO) was developed to capture the breadth and depth of the system and address interactions and connections between separate system components. SECO develops a practical integrated approach using accessible methods for addressing a large complex ocean system such as the WCP tuna fisheries. The framework offers a rapid transdisciplinary assessment and opens space for their deeper transdisciplinary analyses. This exploratory framework, as the WCP tuna case example shows, starts to reveal issues at scales that are not likely to be addressed by the strong single disciplinary approaches to governance now prevailing. The transdisciplinary research approach was developed to be responsive to diverse participants’ knowledge, including local communities, scientists (social and biophysical), industry experts, economists, and fisheries managers. SECO was applied to place-specific studies, Suva, Fiji and Honiara and Gizo, Solomon Islands in the WCP tuna fishery. This validated SECO to ensure robustness and reliability.
... With an overall historical coverage of <1%, longline fleets within the convention area were required to increase their observer coverage to 5% as of June 2012. While compliance with this requirement has improved in recent years, it has not been met in some parts of the convention area, including Palau's LBF, in recent years (Peatman and Nicol, 2020;Williams and Ruaia, 2020). ...
Article
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Bycatch on pelagic tuna longlines has contributed to population declines in several far-ranging, oceanic species and presents a conservation challenge that area-based management tools are increasingly promoted to address. In January 2020 the Republic of Palau, concerned about the impacts of longline fishing in its waters, closed 80% of its exclusive economic zone to all extractive activities, reserving the remaining 20% for a domestic fishing zone (DFZ). One of a growing number of very large marine protected areas, the Palau National Marine Sanctuary (PNMS) spans ∼500,000 km 2 and was established inter alia to allow for the recovery of fish stocks adversely impacted by tuna longline fleets. Given that the main tuna stocks targeted in the western Pacific are not overexploited, the benefits of protection potentially afforded by the sanctuary are likely greater for vulnerable bycatch species. Evaluations of the sanctuary's performance require, in part, a baseline of historical catch rates and effort distribution in the distant-water fleet (DWF) and locally based fleet (LBF) operating in Palau prior to sanctuary implementation. We describe the fishing effort, catch rates, catch estimates and fishing mortality in Palau's longline fishery based on logbook, observer and electronic monitoring data. We defined bycatch as any species, retained or discarded, other than targeted tunas. Between 2010 and 2020, 104.8 million hooks were deployed, catching over 2 million individuals from 117 taxa at an overall target:bycatch ratio of 1:1, with a retention rate of ∼62%. Pronounced differences in fishing strategies and spatial distribution of effort between fleets were associated with large variations in catch rates and composition. The LBF had a larger effect on populations of at-risk species relative to the DWF, with higher catch rates and magnitudes for several vulnerable species and higher observable fishing mortality rates (64% vs 50% in the DWF). The sanctuary reshaped Palau's longline fishery, contracting the fishery's area and capacity. The relocation of the DFZ eliminated the LBF and constrained the DWF to an area Frontiers in Marine Science | www.frontiersin.org 1 October 2021 | Volume 8 | Article 720603 Jaiteh et al. Bycatch Illuminates Longterm Sanctuary Effects where the fleet's total catch rates and those of a number of vulnerable species were historically lower relative to former fishing grounds now closed by the sanctuary. Our results highlight the importance of consistent bycatch monitoring and emphasize the need for regional area-based approaches for managing longline fisheries.
... Yellowfin tuna is an important component of tuna fisheries throughout the WCPO. They are harvested with a wide variety of gear types, from small-scale artisanal fisheries in Pacific Island and southeast Asian waters to large, distant-water longliners and purse seiners that operate widely in equatorial and tropical waters (Williams and Thomas Ruaia, 2020). Purse seiners catch a wide size range of yellowfin tuna, however, smaller yellowfin often dominate catches associated with FADs (fish aggregation devices), whereas the longline fishery takes mostly larger adult fish (Vidal and Hamer, 2020;Williams and Thomas Ruaia, 2020). ...
... They are harvested with a wide variety of gear types, from small-scale artisanal fisheries in Pacific Island and southeast Asian waters to large, distant-water longliners and purse seiners that operate widely in equatorial and tropical waters (Williams and Thomas Ruaia, 2020). Purse seiners catch a wide size range of yellowfin tuna, however, smaller yellowfin often dominate catches associated with FADs (fish aggregation devices), whereas the longline fishery takes mostly larger adult fish (Vidal and Hamer, 2020;Williams and Thomas Ruaia, 2020). ...
... The annual yellowfin tuna catch in the WCPO increased from 100,000 mt in 1970 to between 600,000 -700,000 mt in recent years, mainly due to increased catches in the purse seine fishery, (Williams and Thomas Ruaia, 2020 Figure 3). Figure 5 shows the spatial distribution of yellowfin tuna catch in the WCPO for the past 10 years. ...
Article
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Fisheries harvest strategies are formal frameworks that represent a best-practice approach for sustainable fisheries management. A key component of a harvest strategy is a 'pre-agreed rule', known as a harvest control rule (HCR), that sets fishing opportunities, e.g. catch limits, based on an estimate of fish stock status, e.g. estimated stock biomass. The harvest strategy development process is driven by stakeholders who are required to make a range of informed decisions, including on the selection of the preferred HCR. Capacity building may be required to facilitate the stakeholder engagement, particularly regarding the technical components of harvest strategies, including HCRs. The AMPLE package for R provides three interactive apps that support capacity building and stakeholder engagement on HCRs. These apps have been used during in-country national workshops around the western and central Pacific Ocean (WCPO) to support the development of harvest strategies for the Western and Central Pacific Fisheries Commission. These apps include several novel features: they take users from a gentle introduction to how HCRs work, to using methods for testing, comparing and selecting a preferred HCR from a suite of candidates. They include an introduction to the impact of uncertainty on the performance of an HCR, introduce performance indicators and discuss methods for selecting the preferred HCR based on management objectives. As such they provide a more detailed overview of HCRs than currently existing alternatives. These apps provide an effective platform for hands-on learning and have proven to be successful at supporting capacity building on HCRs in the WCPO. For example, using them for group activities and competitions stimulated productive discussions and increased understanding. As the model fishery in AMPLE is generic and not based on a real example, the apps will also be of interest to scientists, managers and stakeholders developing harvest strategies in other regions.
Article
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Abundance indices derived from fisheries-dependent data (catch-per-unit-effort or CPUE) are known to have potential for bias, in part because of the usual non-random nature of fisheries spatial distributions. However, given the cost and lack of availability of fisheries-independent surveys, fisheries-dependent CPUE remains a common and informative input to fisheries stock assessments. Recent research efforts have focused on the development of spatiotemporal delta-generalized linear mixed models (GLMMs) which simultaneously standardize the CPUE and predict abundance in unfished areas when estimating the abundance index. These models can include local seasonal environmental covariates (e.g. sea surface temperature) and a spatially varying response to regional annual indices (e.g. the El Niño Southern Oscillation) to interpolate into unfished areas. Spatiotemporal delta-GLMMs have been demonstrated in simulation studies to perform better than conventional, non-spatial delta-generalized linear models (GLMs). However, spatiotemporal delta-GLMMs have rarely been evaluated in situations where fisheries spatial sampling patterns change over time (e.g. fisheries expansion or spatial closures). This study develops a simulation framework to evaluate 1) how the nature of fisheries-dependent spatial sampling patterns may bias estimated abundance indices, 2) how shifts in spatial sampling over time impact our ability to estimate temporal changes in catchability, and 3) how including seasonal environmental covariates and/or regional annual indices in spatiotemporal delta-GLMMs can improve the estimation of abundance indices given shifts in spatial sampling. Spatiotemporal delta-GLMMs are then applied to a case study example where the spatial sampling pattern changed dramatically over time (contraction of the Japanese pole-and-line fishery for skipjack tuna Katsuwonus pelamis in the western and central Pacific Ocean). Results from simulations indicate that spatial sampling in proportion to the underlying biomass can produce similar abundance indices to those produced under random sampling. Though estimated abundance indices were not perfect, spatiotemporal GLMMs were generally able to disentangle shifts in spatial sampling from temporal changes in catchability when shifts in spatial sampling were not too extreme. Lastly, the inclusion of seasonal environmental covariates and/or regional oceanographic indices in spatiotemporal GLMMs did not improve abundance index estimation and in some cases resulted in degraded model performance.