Distributing the bigeye conservation burden in the western and central pacific fisheries

The Western and Central Pacific Ocean is home to the world's most productive tuna fisheries, with the majority of tuna catches occurring inside the exclusive economic zones (EEZs) of the region's developing coastal States. It is important that these fisheries are managed effectively throughout their range, both within and between EEZs and on the high seas. Unrestrained exploitation in a particular EEZ or on the high seas has the potential to significantly impact on catches elsewhere with potentially devastating consequences for developing coastal States, some of which have few alternate resources. The Western and Central Pacific Fisheries Commission (WCPFC) was established in 2004 to manage the region's highly migratory tuna fisheries. However, the WCPFC has since repeatedly failed to adopt conservation and management measures that are sufficient to meet the WCPFC's conservation and sustainable use objectives. This paper analyses catch data from the WCPFC and suggests that the weak position of bigeye (in a strategic political context), the unwillingness of members to compromise their interests and the lack of a transparent framework for distributing the burden of conservation are key factors in the WCPFC's failure to adopt sufficiently strong conservation and management measures.     

Introducing a transferable fishing day management regime for Pacific Island countries

On 1 December 2007, eight ‘Small Island Developing States’ in the Western and Central Pacific Ocean implemented a management regime restricting the total number of days fished by tuna purse seine vessels within their waters, commonly referred to as the Vessel Day Scheme (VDS). The VDS is seen as one component of management arrangements to reduce fishing mortality on bigeye and yellowfin tuna, constrain fishing effort, and increase the rate of return from access fees by Distant Water Fishing Nations.     

中西太平洋延绳钓黄鳍金枪鱼渔场时空分布与温跃层关系

为了解热带中西太平洋延绳钓黄鳍金枪鱼(Thunnus albacares)适宜的温跃层参数分布区间,采用Argo浮标温度信息和中西太平洋渔业委员会(The Western and Central Pacific Fisheries Commission,WCPFC)的黄鳍金枪鱼延绳钓渔获数据,绘制了热带中西太平洋月平均温跃层特征参数和月平均CPUE的空间叠加图,用于分析热带中西太平洋黄鳍金枪鱼中心渔场时空分布和温跃层特征参数间的关系。分析结果表明:热带中西太平洋温跃层上界深度、温度具有明显的季节性变化,而温跃层下界深度、温度季节性变化不明显,黄鳍金枪鱼中心渔场分布和温跃层季节性变化有关。全年中心渔场的位置分布在温跃层上界深度高值区域,随温跃层上界深度高值区域季节性南北移动。在新几内亚以东纬向区域(5°N~10°S,150°E~170°W)上界深度值全年都在70~100m之间,全年都是延绳钓黄鳍金枪鱼中心渔场。中心渔场上界温度多在26℃以上,但是在上界温度超过30℃区域,CPUE值较小。中心渔场主要分布在温跃层下界深度两条高值带之间区域,在温跃层下界深度超过300m和小于150m区域,CPUE值均偏低。中心渔场主要分布在下界温度低于13℃区域,下界温度超过17℃难以形成中心渔场。频次分析和经验累积分布函数计算其适宜温跃层特征参数分布,得出中西太平洋黄鳍金枪鱼适宜的温跃层上界温度和深度分别是27~29.9℃和70~109m;适宜的温跃层下界温度和深度分别是11~13.9℃和250~299m。文章初步得出中西太平洋黄鳍金枪鱼中心渔场温跃层各特征参数的适宜分布区间及季节变化特征,为我国金枪鱼实际生产作业提供技术支持。     

The structure of tuna access agreements in the Western and Central Pacific Ocean: Lessons for Vessel Day Scheme planning

The tuna industry in the Western and Central Pacific Ocean (WCPO) is one of the largest and most valuable fisheries in the world. Since the 1980s, Pacific island countries have used licensing agreements with foreign fishing interests—known as access agreements—to earn tuna-related revenue and control the environmental impacts of fishing, with only minimal success. To date, there has been little work detailing the structure of access agreements and assessing how this structure relates to economic and environmental outcomes in the sector. This article helps to fill this gap by providing an overview of various access structures and a detailed empirical assessment of how these structures are applied in access agreements between Pacific island countries and the major foreign fishing interests active in the WCPO. This analysis is placed in the context of evolving regional fisheries management structures. The study reveals that while there is no uniform formula for access agreements, each structure is subject to distinct political, economic and environmental considerations that influence outcomes for Pacific island countries. As Pacific island countries develop the mechanism to allocate fishing rights under the new Vessel Day Scheme, drawing on their long history with access agreements will assist efforts to use access to achieve policy objectives. Improved transparency will enable Pacific island countries to identify successes and problems and adapt the Vessel Day Scheme allocation mechanisms accordingly.     

Full retention in tuna fisheries: Benefits,costs and unintended consequences

Several tuna regional fisheries management organizations (t-RFMOs) have adopted retention requirements for skipjack, bigeye and yellowfin tunas caught by purse seine vessels to reduce discards, create disincentives to catch small fish, and incentivize the development and adoption of more selective technologies. Although retention policies in the t-RFMOs have been limited to target tunas in purse seine fisheries, some have advocated for an expansion of those policies, and t-RFMOs could consider expanding retention policies to a greater number of species and/or to other gear types. This paper discusses the benefits and costs of broader retention policies for purse seine and longline tuna fisheries in the western and central Pacific Ocean (WCPO). Using bycatch data from observers and logbooks from the U.S. purse seine and longline fleets operating in the WCPO, this paper documents the types and magnitude of fish discarded. For the purse seine fishery, this information was used to estimate direct impacts of having to off-load at the initial point of landing in key Pacific Island ports. For the longline fishery, estimates of direct impacts were limited to Honolulu and Pago Pago, American Samoa, the two primary ports where U.S. catch is landed. Expanding retention policies beyond the target tunas and to other gear types would further reduce discarding and possibly provide stronger incentives to develop and use more selective techniques. Beyond impacts to the ecosystem and fisher behavior, adopting broader retention policies may have other implications, and this paper explores those implications on vessels, processors, and communities. In general, as is the case with most direct interventions on fishing operations, there will be both benefits and costs, and the magnitude of those impacts will depend on the scope and extent of any expanded retention policy.     

Tuna dreams and tuna realities: Defining the term “maximising economic returns from the tuna fisheries” in six Pacific Island states

Previous work on identifying opportunities for Pacific Island countries to improve the economic returns from their tuna resources in the Western and Central Pacific Ocean (WCPO) has not generally included articulation of aspirations from Islanders themselves. However, generating such an understanding is increasingly important as these countries assert their positions in regional fisheries policy making. This study analyses the self-identified aspirations of industry and government representatives from six Pacific Island countries and finds a wider diversity of attitudes, strategies and success than is generally recognised. Implications for negotiations in the WCPFC are then discussed.     

Subsidies to tuna fisheries in the Western Central Pacific Ocean

Tuna fisheries in the Western and Central Pacific Ocean are among the most valuable resources in the region. These fisheries, worth an estimated $4.1 billion each year, play a pivotal role in supporting incomes and development goals in the region. However, due to the twin, and potentially inter-related effects of harmful fishing practices such as the use of fish aggregating devices, overcapacity, and fisheries subsidies, many of these tuna fisheries are currently at risk of over-exploitation—putting the livelihoods of countless local fishers at risk. This study finds that government fisheries subsidies in the region represent 37% of the ex-vessel value of tuna fisheries in the region. Fuel subsidies are estimated at US$ 335 million and non-fuel subsidies are estimated at US$ 1.2 billion for the year 2009. Developed countries are responsible for more than half of the subsidies spent in the predominantly developing region, underlying the fact that the majority of tuna value extracted from the national waters of developing countries in the region benefit larger, developed countries. The total resource rent, or return to society, from tuna fisheries, once adjusted for subsidies is a net negative US$750 million in 2009. Fisheries subsidies are enabling foreign fleets to operate at sub-market rates, putting local fleets out of competition for their own fishery resources.     

中西太平洋金枪鱼围网技术及存在的问题

金枪鱼围网产量约占全球金枪鱼捕获量的70%,发展金枪鱼围网渔业具有广阔的前景.本文根据中鲁远洋渔业股份有限公司金枪鱼围网渔船的作业情况,分析了围网作业中的一些捕捞技术,并探讨了在发展该项目中存在的问题.     

The biological oceanography of the East Australian Current and surrounding waters in relation to tuna and billfish catches off eastern Australia

The surface and sub-surface biological oceanography of tuna fishing grounds within the East Australian Current (EAC) was compared in 2004 with two other fishing areas further offshore. Our aim was to determine whether the biological oceanography of the region could explain the distribution and intensity of pelagic fishery catches inside and outside the EAC at that time. The EAC fishing area was noticeably warmer, less saline and lower in nutrients than waters in the other fishing areas. The EAC waters were dominated by large diatoms, the biomass of which was significantly higher than in the seamount and offshore areas, apparently the result of a cold core eddy beneath the EAC surface filament. Over the seamount and offshore more typical Tasman Sea waters prevailed, although the presence of a relatively deeper oxygen minimum layer over the seamount suggested topographically induced mixing in the area. Notably, sub-surface zooplankton and micronekton biomass was significantly higher around the seamount than in the two other areas. The offshore region was characterised by frontal activity associated with the Tasman front. Micronekton net biomass was generally highest in surface waters in this region. Examination of tuna catch records at that time showed yellowfin tuna (Thunnus albacares) dominated the catches of the EAC, whereas swordfish (Xiphias gladius) and bigeye tuna (Thunnus obesus) were the main species caught offshore. We suggest the yellowfin tuna concentrate in waters that are not only warmer but where prey species are concentrated near the surface. Offshore, deeper living species such as swordfish and bigeye tuna (T. obesus) can take advantage of prey species that are distributed deeper in the water column and along the flanks of the many seamounts in the region, or that are concentrated at fronts associated with the Tasman Front. Although only a snapshot of the region, relatively consistent catch data over time suggests the underlying biological oceanography may persist over longer time periods, particularly during the Austral spring.     

Optimising fisheries management in relation to tuna catches in the western central Pacific Ocean: A review of research priorities and opportunities

Some of the most important development goals for the countries and territories of the Western and Central Pacific Ocean (WCPO) involve the sustainable management of their fisheries in light of environmental, economic and social uncertainties. The responses of fish populations to variability in the marine environment have implications for decision making processes associated with resource management. There is still considerable uncertainty in estimating the responses of tuna populations to short-to-medium-term variability and longer-term change in the oceanic environment. A workshop was organised to examine how advances in oceanography, fisheries science and fisheries economics could be applied to the tuna fisheries of the WCPO and in doing so identify research priorities to improve understanding relevant to progressing management. Research priorities identified included: (i) improved parameterisation of end to end ecosystem model components, processes and feedbacks through expanded biological observations and incorporation of higher resolution climate models; (ii) development of seasonal and inter-annual forecasting tools enabling management responses to short-term variability in tuna distributions and abundances; (iii) improved understanding of the population dynamics of and the energy transfer efficiencies between food web components; (iv) assessment of the optimal value of access rights and overall fishery value under multiple scenarios of tuna distribution and abundance and influences on decision making by fisheries managers and fleets and (v) development of management strategy evaluation frameworks for utilisation in the implementing and testing of fishery management procedures and to help prioritise research directions and investment. Issues discussed and research priorities identified during the workshop have synergies with other internationally managed fisheries and therefore are applicable to many other fisheries.     

Ecological Risk Assessment for seabird interactions in Western and Central Pacific longline fisheries

The risk of seabird–fishery interactions in the Western and Central Pacific Ocean (WCPO) was examined by analysing the overlap of seabird distributions with tuna and swordfish pelagic longline fisheries managed by the Western and Central Pacific Fisheries Commission (WCPFC) and its constituent members. The study used spatially-explicit Productivity–Susceptibility Analysis (PSA). Key data inputs were species productivity, fishing effort, likelihood of capture and species density by region. The outputs tailored results to the needs of fisheries- and wildlife-managers, indicating areas of greatest risk of species interactions, species of greatest concern for population impacts, and the flags or fisheries most likely to contribute to the risk. Large albatross species were found to be most likely to suffer population effects when exposed to longline fishing activity, followed by the larger petrels from the genuses Procellaria, Macronectes and Pterodroma. A mixture of coastal states with nesting seabird populations in their Exclusive Economic Zones (New Zealand, Australia and United States of America), distant water fishing nations (Japan, Taiwan) and flags of convenience (Vanuatu) contributed 90% of the risk to seabird populations. Recommendations include enhancing the level of fisheries observer monitoring in areas indicated as high to medium risk for seabird interactions, and consideration of spatial management tools, such as more intensive or more stringent seabird bycatch mitigation requirements in high- to medium-risk areas. The methods used, and similar studies conducted in the Atlantic Ocean could lead to improved targeting of monitoring resources, and greater specificity in the needs for seabird-mitigation measures. This will assist in reducing seabird mortality in longline fishing operations and with more effective use of resources for fishery managers in both domestic fisheries and RFMOs.     

Governance of tuna industries: The key to economic viability and sustainability in the Western and Central Pacific Ocean

The Western and Central Pacific Ocean (WCPO) tuna fishery is an important global food resource, and the economies of many Pacific Islands Countries (PICs) rely heavily on tuna industries. This paper proposes that governance by PICs is the key to improving the sustainability and profitability of tuna industries in the region. ‘Governance’ is usually used to refer to corruption, but here is interpreted more broadly to encompass the whole process by which decisions regarding public life are made and enacted, by government and also civil society. Argument is supported by empirical material from an interview study with stakeholders and a survey of reports.     

Simulating the impacts of fishing on central and eastern tropical Pacific ecosystem using multispecies size-spectrum model

The size-spectrum model has been considered a useful tool for understanding the structures of marine ecosystems and examining management implications for fisheries. Based on Chinese tuna longline observer data from the central and eastern tropical Pacific Ocean and published data, we developed and calibrated a multispecies size-spectrum model of twenty common and commercially important species in this area. We then use the model to project the status of the species from 2016 to 2050 under five c...     

大眼金枪鱼的资源现状

大眼金枪鱼的分布很广 ,在南、北纬 4 0°以内的太平洋、印度洋和大西洋均有分布 ,是金枪鱼渔业的重要捕捞种类之一。本文分别论述了大眼金枪鱼在大西洋、印度洋和太平洋的渔业概况、生物学特性、资源状况和管理对策。     

金枪鱼延绳钓不同位置钓钩渔获效率的研究

本文从金枪鱼延绳钓渔具的结构及渔获效果入手 ,分析了大眼金枪鱼 (Thunnus obesus)和黄鳍金枪鱼 (Thunnus albacares)的垂直分布及该延绳钓渔具不同位置钓钩的渔获效率 ,据以对钓具的性能做出初步评价 ,并提出了改进的建议     

The exclusive economic zone and economic development in the Pacific island countries

The exclusive economic zone (EEZ) became accepted internationally in the 1970s. This transferred resource wealth to the coastal states establishing such zones. The history of the EEZ is reviewed, and its impact on the economic development of the Pacific island states considered. The growth performance and the tuna fishery development of these states are reviewed and possible causes of limited success discussed. The use of trust funds to increase the resource wealth of the Pacific island states is briefly considered.     

大西洋金枪鱼渔业现状分析

本文采用大西洋国际金抢鱼保护委员会ICCAT的报告和统计常设委员会（SCRS）数据库，统计分析了1978-2002年大西洋金抢鱼的渔获种类及渔具渔法。结果表明：按种类分黄鳍金枪鱼（占28％）、鲣鱼（22％）、长鳍金枪鱼（15％）、大眼金枪鱼（11％）、其他种类（8％）；按渔具分围网（42％）、延绳钓（29％）、饵钓（22％）、其它渔具（7％）。同时分析了不同海域的渔获种类、渔获量波动情况和原因。     

中部太平洋大眼金枪鱼种群遗传结构的初步研究

大眼金枪鱼是世界最重要的渔业资源之一,经济价值较高,捕捞压力的加大使中部太平洋大眼金枪鱼过度捕捞程度愈发严重。开展种群遗传结构研究将为大眼金枪鱼资源的可持续利用与开发提供科学依据。本文以取自中西太平洋和中东太平洋共182尾大眼金枪鱼个体为研究对象,分析研究其线粒体DNA控制区第一个高变区（the first hypervariable region,HVR-1）457bp的序列,共发现115个变异位点,定义了178种单倍型。序列多样性分析结果显示8个采样点核苷酸多样性在0.03074-0.04362间,单倍型多样性在各个采样点都较高,变动范围在0.996-1.000之间;分子方差分析显示99.97%的遗传变异性来自于种群内;群体间的高基因交流值Nm和低分化指数Fst揭示中东太平洋与中西太平洋群体间基因交流频繁,不存在显著的遗传分化。     

Socio-economic drivers and indicators for artisanal coastal fisheries in Pacific island countries and territories and their use for fisheries management strategies

This is the first regional study of artisanal fisheries in Pacific Island countries and territories that demonstrated that the future of the region's artisanal fishery sector and the livelihood of coastal communities will be highly dependent on alternative subsistence and income sources, which are necessary to reduce fishing pressure to a sustainable level to maintain ecosystem services and food security. The overall objective of this study was to identify socio-economic indicators and drivers to improve the understanding of the dynamics between socio-economic conditions and current exploitation levels of finfish and invertebrates of coastal communities in 17 Pacific Island countries and territories. We showed that exploitation rates and thus possible overexploitation are not solely the consequence of a simple demographic growth process but are in fact a result of the choices people have. Our results confirmed a close relationship between resource exploitation rates and economic development at the national level and the availability of alternative income opportunities at the community level. Multivariate analysis results suggest that communities in countries with somewhat unfavourable conditions and limited access to alternatives and fishing households in communities with overall favourable economic conditions are at highest vulnerability as they have the highest dependence on coastal fisheries resources. Alternative economic opportunities at the national scale and availability of alternative income at the community level vary significantly between cultural groups. Based on our results, the development of management strategies with realistic expectations of ensuring livelihood of coastal communities and sustainable resource use in Pacific Island countries and territories requires a hierarchical and integral approach. Major drivers identified at the regional, cultural and local levels should be used to identify priorities, to assess overall advantages and limitations at the different levels as well as the vulnerability of communities targeted, and to develop strategies accordingly.     

Rethinking the principle of abstention: the North Pacific and beyond

While the principle of abstention was established as part of the International North Pacific Fishery Convention in 1952, it was generally overlooked for several decades afterwards. The 1995 Straddling Stocks Agreement says that states parties to the Agreement enjoy a right to access to high seas fishery resources, but on the condition that they respect existing regional conservation and management measures. This Agreement also introduces the concept of a precautionary approach. The end result is that the 1995 Agreement fulfilled the same intent of the original 1952 principle of abstention—that is, it places some kinds of restrictions on high seas fishing. The degree of restrictions depends on the activities and policies of new regional fishery organizations like WCPFC and so on. Even if the new version of the principle of abstention succeeds in excluding distant fishing states from high seas, it will do little to solve the larger problems facing today's ocean fishery resources.