Community‐based monitoring of small‐scale fisheries with digital devices in Brazilian Amazon

Fisheries management is potentially a short‐term measure for reducing floodplain fisheries degradation. This objective can only be achieved if adequate measures to improve fishery governance and ecosystem conservation are taken. The monitoring of fisheries management is likely to be important for understanding the effectiveness of local rules and the impacts on aquatic biodiversity. Given that monitoring is the periodic assessment of fish stock characteristics regarding reference data, adopting tools and procedures for monitoring at different scales is a challenging task. Information and Communication Technologies (ICT) have enabled local communities to gather data on key resources in a cost‐effective way. This article presents a community‐based monitoring of fisheries based of smartphones that supports the annual fishing quotas and legal harvest permits procedures. The precision of community‐based monitoring data is assessed and a model to integrate these data into a large‐scale monitoring scheme examined. Data collection performance was evaluated at communities in the Kaxinawá Nova Olinda Indigenous Territory, in the State of Acre, where fishery management was monitored. The results indicate that voluntary collectors are able to provide data with precision comparable with government agency measurements, but at lower cost.     

Fishing agreements in the lower Amazon: for gain and restraint

Abstract  Co-management agreements, whereby community rules for the management of local floodplain lake fisheries are legalised and enforced by the government, have become common in the lower Amazon. Agreements are intended to limit exploitation, in particular by commercial boats, to raise stock abundance and fisheries productivity for the benefit of local subsistence-oriented fishers and for conservation. A spatially replicated observational study was carried out to evaluate the performance of fishing agreements in terms of perceived rule compliance and actual impacts on fishing activities, catch and catch per unit of effort (CPUE, a measure of fisheries productivity and proxy for stock abundance). Perceived rule compliance was high, and this was corroborated by observed changes in fishing practices. Catch per unit of effort was significantly higher (by 48% on average) in areas subject to fishing agreements than in control areas without. Most likely this effect was attributable to the effective exclusion of mobile commercial fishing boats. Household fishing effort and catch in local communities were not significantly affected by the agreements, although a tendency towards slightly higher catches at lower effort was noticeable. In conclusion, the co-management agreements have led to greater local control over resources and brought significant productivity and conservation benefits.     

福建省近海渔业管理目标的比较

应用Schaefer和Fox剩余产量模式及其由此衍生的生物经济模式和Gulland最适产量Y0．1模式，分别估算了福建省近海海洋捕捞业的最大持续产量，最大持续捕捞力量，最适产量，最适捕捞力量，最大经济产量，最大经济捕捞力量，最佳经济效益，并对各模式计算的诸项经济指标进行比较，建立了渔业管理3种模式，并根据福建省近海渔业实际情况和渔业发展趋势 ，提出实现3种管理目标的实施步骤。     

Commercial fishing in the Brazilian Amazon: regional differentiation in fleet characteristics and efficiency

Regional differentiation in fleet characteristics and economic efficiency, as well as the total elasticity of scale in the commercial fishing fleets of the Brazilian Amazon were analysed. Data were collected in 893 interviews with boat operators in four major ports on the River Amazon. Boats operating from the largest cities (Belém and Manaus) are mostly operated by hired skippers and non‐permanent crews, while boats from smaller cities (Santarém and Tefé) are mostly owner‐operated and use permanent crews. In the lower Amazon, a large proportion of fishermen (89% in Santarém and 53% in Belém) are based in rural areas, while in the upper Amazon commercial fishermen are predominantly urban‐based. A production function analysis identified boat length, gear type used (gill net/purse seine), number of fishermen employed, quantities of fuel and ice used, and education level of the skipper as significant factors determining the catch. The analysis provided no evidence of regional differences in stock levels. The use of purse seines was associated with significantly higher catches (by 32%), all other factors being equal. Purse seines are banned in the lower Amazon (Santarem and Belem), and this results in overall lower levels of technical efficiency in this region. No significant total scale effect on efficiency was detected. These results are discussed with respect to the institutional sustainability of current fisheries co‐management initiatives.     

基于海峡两岸经济合作框架协议的两岸渔业经济合作

归纳总结了《海峡两岸经济合作框架协议》(ECFA)和几个附件的内容,分析了ECFA生效之后,货物贸易早期收获产品清单对渔业动物产品进口的影响。研究认为,从台湾进口水产动物产品税率的降低和趋于零,无疑将大大提升台湾水产动物产品在大陆的竞争力;早期收获计划实施后,台湾出口到大陆的水产动物产品数量将会大幅度提高。这种状况无疑是对大陆水产企业的一种挑战和冲击。只有在不断提高产品质量和安全、不断降低生产成本的情况下,大陆的水产企业才能应对这种挑战,承受这种冲击。在服务贸易方面,如果台湾能够在大陆设立这些方面的企业,提供有关远洋渔业、水产养殖和水产品加工方面的科学研究和开发服务,必将推动我国大陆渔业技术的快速提升,促进渔业经济的健康、快速发展。在投资与经济合作方面,如果在ECFA的框架下,逐步减小双方投资的限制,从目前的侧重第一、第二产业的投资扩展到全方位的投资,涵盖水产苗种繁育、水产品加工、水产饲料、远洋渔业、休闲渔业、科技合作等领域,则必定促进大陆水产产业的整体提升,提高渔业经济的效益。作者对在ECFA框架下的渔业经济合作,从渔业资源养护与管理、休闲渔业等几个方面提出了建议。     

Management of selected Polish commercial and recreational lake fisheries activities

The objective of management of Polish lakes is to fulfil the needs of commercial and recreational fishermen that developed after the political changes of the last decade. The effectiveness of the policies and practices adopted has never been studied. Six lake enterprises were selected, two in each of the lake districts: Mazuria, Pomerania and Great Poland. The two Mazurian enterprises manage a total of 13 325 ha of lakes, the Pomeranian ones 6130 ha and those of Great Poland 4156 ha. All data on commercial fisheries were collected and studies of anglers' activities were carried out through 550 questionnaires. The six enterprises were analysed as a whole and separately, with attention being paid to commercial landings and stockings in 1995–1999, and anglers' catches in 1998. Two enterprises and lakes were chosen for closer analysis. It was estimated that an average lake angler caught 59.2 kg of fish in 1998, and the overall landings by anglers was 35.0 kg ha^–1 yr^–1. Fish yield from lakes was 50.0 kg ha^–1 yr^–1 without considering poachers' catches.     

台湾渔业近况及发展趋势

台湾渔业历史悠久,发展水平相对较高.本文在全面综述近年来台湾渔业相关文献资料的基础上,着重介绍了台湾的渔业发展现状,包括渔业类型、产业技术水平、休闲渔业发展概况及两岸渔业合作和展望等.文章同时分析了台湾渔业发展过程中出现的问题,并指出对其有效的改进手段.本文相关内容可以为我国渔业的发展提供一定的借鉴作用.     

Landings, logbooks and observer surveys: improving the protocols for sampling commercial fisheries

The sampling of commercial marine fisheries for management purposes often displays a key weakness in the form of poor documentation of the scientific basis of sampling and estimation, the assumptions made, and the practical constraints. This paper reviews systematically the theoretical and practical options that can remedy this situation and recommends that decisions be archived in regularly updated ‘Sampling Approach and Modifications’ (SAM) documents. Defining the target population, the observable population (usually a subset of the target), and the assumed links between them is important, along with the distinction between design‐ and model‐based sampling approaches. Fleet‐targeted and stock‐targeted sampling strategies are contrasted, the latter being much harder to implement. Sampling protocols aimed at estimating quantities of fish landed and discarded, length–frequency distributions, length‐related variables such as age, weight and maturity, and ratio variables such as catch per unit of effort and the proportions of discards are discussed, together with the raising of estimates to fleet and/or stock levels. The ideas are summarized in the specific contexts of landings sampling, logbook schemes and sea‐going observer surveys. SAMs are commended for enhancing the scientific value of fishery sampling, and for encouraging methodological discussions among users and producers of the data.     

Social and financial aspects of the artisanal fisheries of Middle São Francisco River, Minas Gerais, Brazil

The presence or absence of motorized boats, partnerships and multispecies catches characterize the fisheries of São Francisco River, Minas Gerais, Brazil. Fishing activity based on 109 interviews, carried out in the wet (high water: February and March) and dry (low water: July and August) seasons, with professional fishermen are described. Aiming to identify the fishery income components, a covariance model was proposed, with the income as the response variable, related to the factors: fishing ground; use of motorized or paddle boat; seasonality; presence of fishing assistant; and the following covariates: capture in weight in the week prior to the interview; fisherman experience in yrs; and distance (km) travelled for fishing. The results indicated that the main contributions to income were the absence of an engine (because of high price of the fuel), the absence of a partner (because of low capture) and the amount of fish caught by the fishermen.     

Stable isotope analysis of energy sources for larvae of eight fish species from the Amazon floodplain

Abstract – Aquatic macrophytes form the most productive habitat of the Amazon floodplain and account for more than 60% of the net primary production of the ecosystem. Aquatic grasses are the dominant macrophytes and the main feeding ground of Amazonian larval fish. The present study used stable isotopes of nitrogen and carbon to measure the contribution of aquatic grasses to the production of eight larval fish, and describes the structure of the trophic chain. The carnivore larvae were at the third trophic level, and the detritivores were at the second and third trophic levels. The contribution of aquatic grasses to larval fish production was variable. It could reach a mean value of 25% for three species, but its contribution probably did not exceed 12% in the other five species.     

渔业资源衰退原因和可持续发展对策

从人为因素出发,分析指出过度捕捞,管理不善,污染严重是渔业资源衰退的主要原因。并从提高公众意识,明确资源产权,发展科学技术等方面展开探讨,以实现渔业资源的可持续发展。     

国际休闲渔业研究进展

为了解长江干流各江段在长江十年禁渔的新形势下垂钓渔业状况,2017—2018年对长江干流872位垂钓者进行了走访调查。结果表明,长江干流垂钓者以中老年人为主,钓具类型主要为手竿和海竿,占钓具总量的80%以上。在长江上游及三峡库区,垂钓者渔具年投入50%以上样本在500元以下;在长江中下游50%以上样本在1000元以上。长江上游、三峡库区、长江中游和长江下游的垂钓者人数分别估算为2 344、4 764、4 600和6 649位,对应江段年垂钓量分别估算为45.0、294.7、171.1和478.7 t,年垂钓量占对应江段鱼类资源现存量比例分别为8.6%、2.0%、1.8%和3.6%;垂钓对长江上游渔业资源影响相对较大,需要密切关注。为引导垂钓渔业的健康、可持续发展,建议划定禁钓区、禁钓期,建立天然水域钓具、钓法的白名单制度,建立科学的管理体制,深入挖掘传统渔业文化资源、树立垂钓渔业品牌。     

不同材料类型人工鱼礁建设的经济效益浅析

对不同人工鱼礁造礁材料的成本和投放成本的调查,从经济学成本管理的角度出发,对不同造礁材料的人工鱼礁产生的经济效益进行了初步的测算和分析,进一步阐明不同人工鱼礁造礁材料的优越性,为人工鱼礁建设事业的可持续健康发展提供依据。同时对人工鱼礁建设所面临的问题及解决问题的具体措施也作了简要的阐述。研究结果表明：钢筋混凝土鱼礁、石料鱼礁可以作为较好的增殖型鱼礁、渔获型鱼礁、游钓型鱼礁的建礁材料;工程塑料鱼礁可以作为浮鱼礁的建礁材料;钢制鱼礁可以将其作为石块或混凝土等鱼礁的钢制框架或筋材,做成增殖型鱼礁、渔获型鱼礁以及游钓型鱼礁;旧轮胎鱼礁建议不要作为鱼礁材料使用;木竹制鱼礁不建议大规模选用为建礁材料。     

The artisanal fishery fleet of the lower Amazon

Abstract  The present study analyses temporal trends in the characteristics of the artisanal fleet landing at ports in the city of Santarém (lower Amazon) from 1993 to 2003. A total of 2714 boats visited the city, accounting for more than 76 000 landings. Of these, 1952 were fishing boats; the others were buyer boats, specialised in the purchase of fish in rural areas for resale in Santarém. The activity involves more than 13 000 fishermen. Fishing boats are made of wood, are on average 11 m long and powered by a 20 hp outboard motor. Boats operate with an average of six to seven fishermen, spending 6 days per trip and catching between 300 and 800 kg of fish. Most variability in yield can be explained by the ice consumed (70%), the number of fishermen trip⁻¹ (19%), fuel consumed (4%) and days spent fishing (3%). The yield changed according to the size, origin and type of boat. Fishing boats coming from more distant locations, in the state of Amazonas, performed better than those from Santarém. Total yield declined slightly during the study period. Mean age of fishing boats and fishing power is increasing. Consumption of ice and fuel by trip, number of fishermen trip⁻¹ and mean days fishing showed positive trends. Financial subsidies from governmental agencies are criticised. Fleet performance and management options are discussed.     

对我国休闲渔业发展的分析

我国休闲渔业的发展有利于渔业经济向多元化方向发展,有利于资源的优化配置,实现可持续发展。本文首先介绍了国内外休闲渔业的发展状况及对构建和谐社会的意义;其次阐述了目前休闲渔业的主要形态;再次分析了制约休闲渔业发展的因素,最后基于分析制约因素的基础上提出了解决制约休闲渔业发展因素的对策。     

Estimating the ecological,economic and social impacts of ocean acidification and warming on UK fisheries

Assessments of the combined ecological impacts of ocean acidification and warming (OAW) and their social and economic consequences can help develop adaptive and responsive management strategies in the most sensitive regions. Here, available observational and experimental data, theoretical, and modelling approaches are combined to project and quantify potential effects of OAW on the future fisheries catches and resulting revenues and employment in the UK under different CO₂ emission scenarios. Across all scenarios, based on the limited available experimental results considered, the bivalve species investigated were more affected by OAW than the fish species considered, compared with ocean warming alone. Projected standing stock biomasses decrease between 10 and 60%. These impacts translate into an overall fish and shellfish catch decrease of between 10 and 30% by 2020 across all areas except for the Scotland >10 m fleet. This latter fleet shows average positive impacts until 2050, declining afterwards. The main driver of the projected decreases is temperature rise (0.5–3.3 °C), which exacerbate the impact of decreases in primary production (10–30%) in UK fishing waters. The inclusion of the effect of ocean acidification on the carbon uptake of primary producers had very little impact on the projections of potential fish and shellfish catches (<1%). The <10 m fleet is likely to be the most impacted by‐catch decreases in the short term (2020–50), whereas the effects will be experienced more strongly by the >10 m fleet by the end of the century in all countries. Overall, losses in revenue are estimated to range between 1 and 21% in the short term (2020–50) with England and Scotland being the most negatively impacted in absolute terms, and Wales and North Ireland in relative terms. Losses in total employment (fisheries and associated industries) may reach approximately 3–20% during 2020–50 with the >10 m fleet and associated industries bearing the majority of the losses.     

基于文献计量的几何形态测量学在渔业中的应用研究进展

几何形态测量学是研究生物形态变异的重要分析方法,在渔业科学及众多领域得到广泛的应用。使用Web of Science核心合集数据库检索到733篇文献,运用基于CiteSpace软件的文献计量学分析方法,对发文量趋势、期刊、作者、国家/地区、研究机构、高被引文献进行分析,并结合关键词网络知识图谱、突变检测,探究了几何形态测量学在渔业领域中的应用研究热点以及未来发展趋势。分析结果表明,渔业领域研究发文量呈现出交替增减但整体上升的趋势,以美国为主的欧美国家在该领域有较多的研究,澳大利亚、日本及我国研究相对较少。软件应用、鉴别分类、发育和演化、生态形态学仍是目前研究重点,软件开发、立体几何形态学、人工智能形态学是未来研究的重点方向。     

中国渔业的要素投入、规模报酬与技术效率分析

近年来,中国不断加大渔业科技投入,但中国渔业技术效率表现如何,渔业要素投入结构是否合理,都是值得关注的问题.本研究运用CD随机前沿生产函数,通过对2012-2019年全国29个省的232组面板数据进行测算,分析渔业要素投入结构和渔业技术效率.结果 显示:①中国渔业从业人员、渔业养殖面积、机动渔船功率水平、鱼苗投入要素弹...     

The epidemiology of Argulus spp. (Crustacea: Branchiura) infections in stillwater trout fisheries

Problem infections caused by species of the crustacean ectoparasite, Argulus, in UK stillwater trout fisheries appear to have increased in recent years. A cross-sectional study of 77 such fisheries was conducted to establish the perceived problem and the extent and severity of this problem, and to identify associated risk factors. An interview-based study was conducted in 2001 using a standardized questionnaire based on the management and infection status of each fishery in the previous year. Logistic regression was used to identify potential risk factors. Argulus spp. were perceived to cause economic losses in infected fisheries through a reduction in the number of anglers due to reduced aesthetic appeal and catchability of fish. Of the sites studied, 29% experienced such a problem infection in 2000. Argulus foliaceus was identified in all but one case and was found to be widely distributed throughout the UK. The remaining case was identified as Argulus coregoni. Three risk factors were associated with problem infections: the presence of an algal bloom, slow rates of stock turnover and whether water level dropped by <1 m during the summer months.