Social, economic and cultural perspectives of European inland fisheries: review of the EIFAC symposium on fisheries and society

The contributions presented at the EIFAC Symposium on Fisheries and Society in 2000 are reviewed. There have been considerable advances in many sectors of inland fisheries over the past decade. Nowadays the value of inland fisheries to society is generally better understood and increasingly recognized. However, it was recognized that the allocation of fishery resources and their management could still be made more effective through more extensive application of the recent approaches and techniques discussed during the Symposium and reviewed in the paper.     

Inland commercial fisheries management in France

The French fisheries management regime is based on public and private ownership of fishing waters associated with a complex multilevel management system. A total of 730 operational commercial inland fisheries were examined by analysis of thematic interviews and questionnaires. Commercial fishermen are beginning to understand the nature of their own activity and its relationship to the concept of sustainable management. Nevertheless, fishermen have to face two major problems: first, they are poorly represented on decision making bodies where anglers are dominant, and secondly their activities are governed by two separate ministries. Opportunities for future development may lie in decision making at the catchment level.     

我国近海渔业资源可持续产出基础研究的热点问题

近海是众多渔业生物的产卵场、育幼场和索饵场,也是优良渔场,支撑着我国海洋渔业资源的世代发生量和“海上粮仓”的可持续产出。近海渔业贡献了80%~90%海洋捕捞产量,在保障水产品供给、增加渔民收入、促进沿海地区海洋经济发展等方面发挥了重要作用。新中国成立以来,以近海渔业资源为切入点,我国科研人员围绕“海洋渔业资源开发与可持续利用”的关键科技问题,系统开展了一系列渔业资源调查与评估、基础与应用基础研究、技术研发工作,取得了多项创新性成果,支撑了我国海洋渔业资源合理利用、科学养护与管理。渔业资源研究重点与渔业资源开发利用程度和渔业发展休戚相关,本文结合不同时期国家渔业发展战略,系统回顾了1950年代以来我国近海渔业资源研究4个发展阶段 (起步—发展阶段、快速发展阶段、综合研究阶段和新发展阶段)的特点、研究重点、调查装备及平台建设情况等;梳理了我国在近海渔业资源数量变动与渔场探查、渔业资源高效开发利用、渔业资源调查评估技术研发、科学规范的水生生物资源养护体系形成和海洋生态系统动力学等研究进展和代表性成果,及其对我国近海渔业发展、管理与资源养护政策调整的支撑作用;明确了未来渔业资源研究要注重多学科研究和综合性调查,深入解析渔业生态系统结构与功能的机制和机理,结合经济、社会等因素研发新的渔业资源利用与管理模式,实现“开发中保护,保护中开发”,支撑资源养护型近海捕捞业实施和渔业高质量发展。

     

基于灰色预测模型的我国海洋渔业发展趋势分析

综合应用船舶、机械、信息、新材料等技术,从海洋中捕捞经济渔获物并综合利用,是现代海洋捕捞业的主要特征。海洋捕捞技术的发展和创新,对保障我国食物安全、保护近海生态与资源、实现渔民增收和新渔村建设、推动渔业产业结构调整和转型、维护我国海洋权益等方面具有非常重要的作用。本文通过简析海洋捕捞渔场探测、渔具渔法与高效自动化辅渔助渔技术等方面的研究进展,提出海洋捕捞技术的重点发展方向,以期为我国海洋捕捞实现节能高效、生态友好和资源可持续利用,海洋捕捞技术升级和产业高质量发展提供参考。

     

公海金枪鱼渔业管理趋势研究

区域性渔业管理组织 (RFMO)是当前国际公海渔业管理的主要机制,也是公海渔业管理研究的重点之一。西方远洋渔业发展起步早,国外学者较早开始关注RFMO,开展了大量的RFMO理论和实践研究。本文采用文献计量分析梳理了RFMO国外研究,并以知识图谱方式呈现国外研究进展与热点。定量分析结果显示,RFMO国外研究数量总体呈上升趋势;研究领域涉及渔业、环境和国际关系等自然和社会科学;美国、英国和澳大利亚等对研究的关注度较高。此外,关键词分析结果表明,国外学者比较关注RFMO视角下的渔业管理、南大洋等重要海域、气候变化、生态系统、海洋保护区、海洋法等问题,研究重点呈现出从生物资源生物学逐步转向公海生物资源管理和海洋生态系统保护等的趋势。在此基础上,本文进一步定性分析了RFMO国外研究,发现RFMO国外研究更敢于以创新性研究视角探索传统的RFMO研究话题,研究方法更趋科学性,注重研究的辩证性、整体性、比较性和连续性,研究意识也比较超前,善于发现RFMO研究的新领域。本文通过定量和定性分析RFMO研究文献,探究RFMO国外研究进展,为国内学者切实提升RFMO研究的深度和广度提供参考和思路。

     

Optimising codend configuration in a multispecies demersal trawl fishery

Abstract The relative efficiencies and selectivities of conventional and modified codends were examined in a demersal trawl fishery targeting several species, including eastern king prawns, Penaeus plebejus (Hess), whiting, Sillago spp. and cephalopods. The modifications to codends included: (i) reducing the circumference; (ii) increasing the mesh size in conventional diamond‐mesh designs; and (iii) orientating meshes on the bar so that they were square shaped. The codends were tested against a fine‐meshed control in paired comparisons onboard three commercial trawlers. The conventional codend comprised 41‐mm diamond‐shaped mesh attached to an anterior extension section at a ratio of 150 to 100 meshes and was demonstrated to be non‐selective for the targeted species. Reducing codend circumference to 100 meshes and increasing the size of mesh to 45 mm both improved selection for eastern king prawns, but the lateral mesh openings were estimated to be insufficient to allow juveniles of the other key species to escape. By contrast, codends made from 35‐ and 41‐mm mesh hung on the bar improved the size selection for eastern king prawns and selected stout whiting, Sillago robusta (Stead) (the smallest commercial‐sized fish) across narrow selection ranges and at 50% sizes of retention (L₅₀s) that were closely correlated to the transverse morphology of fish and the maximum mesh opening. With the exception of a reduction in catches of octopus, Octopus spp., by the 41‐square codend, there were no other impacts on commercial catches by the square‐mesh designs. It was concluded that diamond‐mesh codends are inappropriate for use throughout this multispecies fishery and that a modified design comprising at least 35‐mm mesh hung on the bar is required to minimise the fishing mortality of unwanted sizes of the key target species. The results are discussed in terms of the utility of these types of modifications for closely regulating selection in penaeid‐shrimp trawls.     

基于生态足迹模型的西部资源型城市可持续发展评价

生态足迹是衡量区域自然资源可持续利用的重要指标。该文运用调整后的生态足迹模型,计算西部9个典型性资源型城市的生态足迹及其生态承载力,并对各城市资源利用程度和生态环境可持续发展状况进行评价与分析。结果表明:西部资源型城市普遍存在生态赤字,表现出较强的不可持续性,而造成这些问题的主要原因就是经济发展对化石能源的高度依赖,使得能源用地的需求量远远大于供给量。最后,文中提出了减少生态足迹需求和增强生态承载力供给的政策建议。     

Competition for shifting resources in the southern Benguela upwelling: Seabirds versus purse-seine fisheries

In the southern Benguela upwelling ecosystem off the west coast of South Africa, seabird populations are decreasing dramatically because of reduced availability of pelagic fish. We tested the hypothesis that the west coast fishing industry is competing for the remaining stocks of anchovy and sardine with the largest colony of Vulnerable Cape Gannets (Morus capensis) along the Atlantic coast. Using GPS-tracking of the birds, echo-sounding of pelagic fish, and vessel log books, we located overlap areas between bird foraging ranges, pelagic fish distribution, and fishing activities. We then compared fish catches by gannets and vessels within their joint foraging zones. In October 2007, purse-seine fishing grounds and gannet foraging areas overlapped by only 13%. However, for a 1-month period, the amount of fish removed from this area by purse-seine boats amounted to 41% of the food requirements of the 72,000 gannets breeding on Malgas Island (25% of the world population). The fishery’s catch in this area is significant in terms of its potential impact on gannets, but comprises only 3.6% of total fishery catch. Based on this finding, the rapidly decreasing size of the gannet colony and the stated objectives of South Africa’s Marine Living Resources Act of 1998, the case for considering and experimenting with at-sea ‘no-take’ areas for the purse-seine fishery is strong. Efforts to establish whether ‘no-take’ fishing zones increase food availability for top predators is an important next step in conservation of the southern Benguela Ecosystem.     

Loggerhead turtle (Caretta caretta) bycatch in Canadian pelagic longline fisheries: Relative importance in the western North Atlantic and opportunities for mitigation

Little is known about the ecology of loggerhead turtles, Caretta caretta, in Canadian waters. However, Canada's eastern waters off the Scotian Shelf, Georges Bank and Grand Banks appear to be seasonal foraging habitats based on dates and locations where they have been captured as fishery bycatch. Estimates derived from data recorded by the international observer program (IOP) and used for this study suggest that thousands of mostly immature loggerheads have been captured in the Canadian pelagic longline fishery (PLF) in the western North Atlantic since 1999. These data suggest that the PLFs for tuna and swordfish are among the most important causes of incidental capture. Although U.S. and Canadian bycatch estimation methods differ and uncertainty associated with the estimates is high, it is clear from the IOP data that bycatch in the Canadian PLF is substantial and roughly within the same magnitude as that reported for the entire U.S. fleet in the North Atlantic for the same period (1999–2005). Analysis of bycatch observer data from the Canadian PLF and other empirical data suggests that fishing at temperatures below 20 °C using fish rather than squid bait and size-18 circle hooks could reduce loggerhead bycatch and mortality. However, research is needed to identify the best options and their commercial viability. Loggerheads that use Canadian Maritime waters are one of the least studied groups of loggerheads in the world, so systematic long-term studies on the ecology of loggerheads in Canada would help fill important information gaps and assist in developing effective recovery plans for this species.