Optimal management of the New Zealand longfin eel (Anguilla dieffenbachii)*

Annual recruitment of the New Zealand longfin eel (Anguilla dieffenbachii) has decreased by 75 per cent since significant levels of commercial fishing began in the early 1970s. This motivates application of a multiple‐cohort bioeconomic model to a New Zealand longfin eel fishery to investigate its optimal management and ascertain the suitability of existing regulatory policy. The use of historical harvest to calculate total allowable catch is asserted to be unsustainable based on recovery dynamics. In addition, individual transferable quota systems are argued to be fundamentally flawed for the protection of longfin fisheries because of high‐grading, low‐surplus production and a current lack of effective stock‐assessment procedures. Area closure and the spatial definition of harvest rights are attractive alternatives given the territoriality of longfins and high larval spillover. The importance of unfished reserves is reinforced when significant uncertainties regarding population strength, harvest intensity and growth dynamics are considered. Restriction of exploitation to older cohorts in fished areas is demonstrated to maximise economic yield.     

How did a network of marine protected areas impact adjacent fisheries? Evidence from Australia

Marine‐protected areas (MPAs) are an effective means of improving habitat quality and biodiversity in the world’s oceans. While the advantages of MPAs as a mechanism for conservation and biodiversity are well established, the potential improvements to fishery performance resulting from a network of MPAs are still being established. Countries around the world have committed to establishing networks of MPAs within their waters by 2020, in response to the United Nations Convention on Biological Diversity. This, coupled with the increasing global demand for seafood and heavy reliance on fishery resources as a source of economic development for many coastal communities, means that an understanding of how these networks can be expected to impact fishery performance is extremely important. We use a difference‐in‐difference modelling approach to isolate the change in the fishery performance associated with the south‐east marine reserve network in Australia. We find no evidence that the economic performance of adjacent fisheries was negatively impacted by the network. This lack of impact is likely due to a network design explicitly intended to avoid effort displacement in key fisheries, along with fishery management changes intended to remove excess fishing capacity.     

The connection between fisheries resources and spatial land use change: The case of two New England fish ports

This study examined interactions between targeted fish populations, aspects of the fishing industry and land use changes along two ports in New England. By tracking changes in land uses over a two-decade period using parcel level data and geographic information system (GIS) tools, we examined the relationship of changes in species biomass, landings and other fishing industry variables to community spatial change. Using logistic regression models we assessed the impacts on essential infrastructure for continued fishing industry activity. Our findings have implications for land use policy that should accompany efforts being made to rehabilitate fish stocks; it should ensure that current marine infrastructure will remain in place to support the fishing industry if and when species rebound. Our models show that in New Bedford Harbor, the larger of the two ports, increasing scallop biomass (considered a long-term factor) is associated with the increase of marine-related land uses. In Provincetown Harbor, short-term factors, such as value and volume of fish landings as well as stock sizes, influence land use change. These findings suggest that the smaller port (Provincetown) is more vulnerable to market conditions and therefore in need of greater land use controls to prevent the conversion of marine-related uses. We propose some directions for further research and present the methodology used as one that can be applied to research questions of a similar nature.     

Economic and ecosystem impacts of illegal,unregulated and unreported (IUU) fishing in Northern Australia*

Illegal foreign fishing for sharks in Northern Australia has increased substantially over the last two decades. This has likely resulted in declines of shark species abundance, with potentially far‐reaching impacts on the ecosystem. This, in turn, could also have indirectly affected the legal prawn, shark, and other fisheries in the region through changed predation patterns and direct removal of targets. The prawn fishery in Northern Australia is currently one of Australia's most valuable fisheries. Sharks themselves are also a major target species by many Queensland and Northern Territory fishers. In this article, an ecosystem model developed in the Ecopath with Ecosim framework is used to estimate the impacts of illegal shark fishing on the remaining system, and the potential economic impacts on commercial fisheries in the region.     

Valuing recreational fishing in Tasmania and assessment of response bias in contingent valuation*

We report results from contingent valuation studies in each of two Tasmanian fisheries that estimate the value of a day’s recreational fishing. Published studies estimating the economic value of recreational fishing in Australia and New Zealand are limited, although the economic and social benefits associated with this activity are sizable and the importance of understanding the behaviour of recreational fishers for the sustainable management of aquatic resources is well recognised. In our contingent valuation surveys, we use a double‐bounded version of the dichotomous choice question, which improves the statistical efficiency of the estimates relative to those based on a single dichotomous choice question. We test and control for response bias, in the form of anchoring and a shift effect, that may occur in data collected using a double‐bounded dichotomous choice (DBDC) elicitation format. We highlight the importance of identifying and correcting for response bias in DBDC models on a case‐by‐case basis. Our estimation results show that there is no significant difference in the willingness to pay for a day of recreational fishing across individuals who caught different number of fish in either fishery. This suggests that high and low catch fishers placed the same value on a day’s fishing.     

实施伏季休渔制度以后的思考

伏季休渔适合我国国情，在国内外产生了重大影响。当前最关键的是要控制捕捞强度，限制渔船增长。现在海洋捕捞计划产量实行"零增长"，将来可能还要提出"负增长"。保护生态环境和渔业资源，实现渔业的可持续发展，是我们的发展目标。     

我国海洋渔业第一产业劳动生产率的增长动力——基于转换份额分析法的实证分析

为研究我国海洋渔业第一产业劳动生产率增长的动力结构,运用转换份额分析法将1989-2014年我国海洋渔业第一产业劳动生产率增长率分解为由产业结构变迁引致的静态与动态结构变迁效应、由技术进步引致的生产率增长效应,结果显示生产率增长效应对海洋渔业第一产业劳动生产率的增长贡献远高于静态与动态结构变迁效应之和的贡献,静态与动态结构变迁效应之和的贡献表现为"先增大、后减少"态势,生产率增长效应的贡献表现为"先逐渐减少、后增大"态势。技术进步是海洋渔业第一产业劳动生产率增长的主要动力;海水养殖业对海洋渔业第一产业劳动生产率增长的贡献大于海洋捕捞业。     

海洋捕捞渔村经济社会现状的调查研究——以宁波海洋捕捞渔村为例

论文以宁波传统海洋捕捞渔村为调查对象,研究了我国东南沿海海洋渔村的经济社会现状.主要研究结果有：①调查样本中,1991～2012年间,2006～2010年渔船增长比例最高,占53％;②吨位200吨以上的渔船占总样本数的77.6％,渔船的平均功率为377马力;调查渔村的双拖网渔船占68％,单拖网渔船占32％,实际作业时间229～331天,作业渔场主要在外海渔场;③渔区劳动力市场具有以下特点,即来自内陆的渔业劳动力数量远大于本地劳动力、雇工工资逐年上涨、工薪结算方式多样化、年轻普通渔业劳动力主要来自内陆、渔民受教育水平偏低等;④宁波海洋捕捞渔民对海洋捕捞生产的依赖性有增强趋势;⑤海洋捕捞产业的经济效率在下降.提出的主要建议有：加强渔业管理与制度建设;加强对海洋捕捞渔业人力资源的教育投入、生存发展环境建设投入、渔村渔区社会建设的投入,实现海洋渔业的可持续发展;减少春夏季作业时间,延长休渔期有助于提高捕捞效率.     

Drug trafficking,cattle ranching and Land use and Land cover change in Guatemala’s Maya Biosphere Reserve

Drug trafficking organizations are driving deforestation in Guatemala’s Maya Biosphere Reserve. Drug traffickers deforest the protected area in order to illegally ranch cattle, which serves as a mechanism of money laundering, drug smuggling, and territory control. Journalists and ethnographers have analyzed “narco-cattle ranching” activities in the reserve and resulting “narco-deforestation,” yet land use change scientists have yet to quantify the contribution of illegal cattle ranching to forest loss. This article uses remote sensing and GIS analysis to distinguish the relative contribution of cattle ranching, farming, and land speculation to reserve deforestation and other forms of land use and land cover change. We also use ethnographic methods to provide evidentiary links between illegal cattle ranching and drug trafficking activities that suggest a large part, but not all, of illegal cattle ranching is narco-capitalized. Our research finds that illegal cattle ranching is responsible for the majority of reserve deforestation, ranging from 59 to 87% of photographs on deforested lands in three sampled areas. We also found illegal cattle ranching activities are the highest in the reserve’s western national parks, which should be strictly protected from land use change. Contrary to popular debate, these findings suggest drug traffickers in the context of the US-led War on Drugs are to blame for forest loss, not subsistence farmers illegally living in the reserve.     

中国海洋渔区“三渔”问题的突围之途

从实现海洋开发可持续发展看,化解"三渔"问题具有重要性和紧迫性。论文利用系统研究方法对"三渔"问题的子系统渔业、渔民、渔村问题的本质进行归纳分析。研究表明,渔业生产过密化、渔民粘连化、渔村过疏化是"三渔"问题的系统性特征,而化解"三渔"问题应当从建设和谐海洋社会,特别是通过现代渔业转型、渔村重生及渔民市民化转型等思路来解决。     

Individual fishing quotas and fishing capacity in the US Gulf of Mexico red snapper fishery

Overcapacity (OC) and excess capacity (EC) are serious obstacles affecting the sound management of commercial fisheries around the world. The use of individual fishing quotas (IFQs) has been proposed as a promising management tool to cope with these challenges. However, the empirical evidence on the efficacy of this instrument is scarce. Drawing on a stochastic distance frontier analysis, we investigate the impact of the US Gulf of Mexico red snapper IFQ program on fishing capacity, capacity utilisation (CU) and OC. The paper also offers an alternative approach to compute species‐specific capacity measurements for multispecies fisheries. Our findings show that following the introduction of the IFQ program, fishing capacity decreased, primarily due to the exit of a large number of fishing vessels. CU increased marginally indicating modest decreases in EC. Conversely, we find that OC remains high. Our estimates suggest that about one‐fifth of the actual fleet could harvest the entire quota.     

Input Controls,Input Substitution and Profit Maximisation in the English Channel Beam Trawl Fishery

Studies of input substitution in fisheries have tended to focus on substitution between physical inputs and/or time fished. However, input controls may create incentives for substitution of other inputs into the production process. For example, fishers faced with constraints on access to particular areas of the fishery may substitute physical inputs for fishing location. This was the case with the UK beam trawl fishery in the English Channel. Constraints were imposed on access to particular areas of the fishery through restrictions on engine power. This created incentives for a number of fishers to reduce their engine power to meet the conditions of the input control. The relative contribution of the boat inputs and location in the production process and the potential for substitution were examined using a translog production function. The results suggested that the apparent input substitution was consistent with profit maximising behaviour.     

面向可持续的渔业补贴:共同渔业政策进入新一轮改革

本文为德国不来梅大学欧洲环境法规研究中心Till Markus发表在Marine Policy 2010年第34卷1117-1124页文章的中译文。2009年4月22日,欧洲委员会发布了"共同渔业政策改革绿皮书",指出该政策的一个矛盾,一方面对渔业领域的公共财政资助是重要的,另一方面这些资助常常与其他共同渔业政策(Common Fishery Policy,CFP)目标,特别是减少生产能力过剩的目标相冲突。文章提供了一种更好理解补贴影响的分析框架,以及对CFP下的基金计划总体评述,旨在解答欧洲委员会在绿皮书中提出的一些问题。问题的解答基于2种观点:海洋捕捞资源的开发最终依赖于可获得的鱼类种群水平,大量的补贴通过刺激投资动机使鱼类资源压力增大。忽视这种趋势的政策导致了无效和不可持续的捕捞以及公共基金的不公分配。虽然近年来CFP下的援助计划有所改观,但仍存在一些问题。未来对渔业的资助必需朝着可持续和有效利用的方向改革。文章对于了解欧盟的渔业补贴政策、增强渔业补贴经济学评价以及促进我国"强渔惠渔"政策的制定与实施等具有一定的参考意义。     

阿根廷渔业与入渔政策

本文详细介绍了阿根廷渔业经济、资源背景，提供了阿根廷的入渔的基本条件和相关要求。     

三沙设施渔业发展战略研究

三沙海域具有丰富的海洋生物资源和岛礁资源,实现三沙海洋强市战略迫切需要发展i沙海洋设施渔业,利用岛礁建设多功能渔港,为三沙渔业发展提供保障。论文介绍了三沙生物资源和岛礁自然条件现状,论述了三沙多功能渔港建设的重要意义与建设要求,分析了三沙多功能渔港建设的发展思路、战略任务与重点研究方向,并提出了加快推进三沙设施渔业和多功能渔港建设的对策建议。     

A GAME THEORY ANALYSIS OF MANAGEMENT STRATEGIES FOR THE SOUTHERN BLUEFIN TUNA INDUSTRY

Game theory offers an alternative approach to standard means of resource assessment which can be of value in the definition and assessment of policy options for competing parties. Using a Nash co-operative game it has been possible in this paper to show the significance of fishing strategies for southern bluefin tuna which take into account the age distribution of the catch. Assuming Japan and Australia act according to a cooperative game then the optimal fishing strategy was found to involve Australia avoiding the fishing of the very young cohorts and Japan taking a moderate catch in subsequent older age classes but not the oldest of the age classes. Sub-optimal strategies were also presented and evaluated along with an indication of the level of biomass associated with different strategies. It was concluded that harvesting policies need to be developed both according to weight of fish harvested and age class.     

海洋捕捞作业影响因素判别及其作用机理

市场经济条件下,海洋捕捞主体生产行为的最优选择是其自身海洋捕捞作业技术水平、海洋捕捞物资性价比、海洋自然渔业资源存量、作业海域生态环境质量、作业海域自然气候条件、渔获物商品化程度和水产市场价格体系综合作用的结果。在其它因素相对不变的条件下,仅有反映水产市场价格体系变化的捕捞物资价格与渔获物价格的比值与海洋捕捞作业规模呈反向关系,其余六个变量均与海洋捕捞作业规模呈正向关系。     

渔业生态标签制度的发展与问题

在如何提高渔业资源可持续利用水平这一国际背景下，FAO倡导创设渔业生态标签并提出了初步设想，随后MSC进一步丰富和发展了这一制度。实践证明，生态标签制度通过市场力量，有助于提高渔业从业者保护渔业资源和环境的意识，因而有助于渔业资源的可持续利用。本文旨在系统介绍渔业生态标签制度的基本理念、发展过程、应用情况及其引发的问题。     

“东海无鱼”应对措施探讨

近年来，东海近海渔业捕捞单位能耗渔获量减少，渔获物中经济鱼类的比重下降，整体营养级水平走低，并且渔获物低龄化、小型化趋势明显，这都说明渔业资源退化已经到了极其严重的地步，严重影响了渔民生计、渔区发展和社会稳定。这一问题的出现表面上看是捕捞过剩和环境污染造成的，但其深层次原因在于我国渔业管理制度不科学，需要进行反思，加强顶层设计，深入研究渔业管理制度和科学保护问题，按照堵疏结合的原则，加强管理和执法的同时，加大资源修复力度。     

商船与渔船碰撞问题研究

近年来,商船与渔船之间碰撞事故频繁发生,已成为水上交通安全生产的重要隐患。究其原因,渔船作业区域与商船航线相互交叉重叠是客观原因;船员安全意识薄弱、船员素质低,疏于瞭望是主观原因;国际海上避碰规则难以有效执行是直接原因;船舶管理不完善、肇事惩罚机制不健全,渔船安全装备设施落后是深层次原因;海洋其他产业与传统渔业争夺水域的矛盾为根本原因。为遏制商船渔船碰撞事故恶化趋势,要科学规划海洋使用功能,合理确定航道和渔业水域;完善法律法规,强化法律责任追究;加大投入,努力提高渔船安全装备水平和救助能力;加强教育培训,提高船员安全生产素质;加强船舶管理,构建渔业、海事部门海上联动机制,加强安全生产保障能力。