赤潮灾害对水产养殖业损失的分级评估

通过分析赤潮灾害损失的构成，建立了一套新的赤潮灾害对水产养殖业损失的评估方法，分别对养殖业的直接经济损失，间接经济损失，赤潮恢复费用等3个方面进行评估，并根据对灾害评估时间要求的不同，将赤潮灾害对养殖业的经济损失评估由粗评到细评，由定性到定量划分为3个等级，即灾前损失预评估，灾时损失评估和灾后损失实评估。最后利用2005年6月发生在浙江南麂列岛赤潮造成水产养殖业灾害损失的实地调查资料，运用建立的分类分级标准进行灾害损失评估。结果表明，此次赤潮属于中型鱼毒赤潮，其直接经济损失为3 100万元，总损失为4 290万元。     

海洋

<正>粤首发海洋灾害公报去年因灾损失74亿元5月27日,广东省发布了该省首个海洋灾害公报《2013年广东省海洋灾害公报》,公报显示,2013年广东各类海洋灾害造成直接经济损失约74.41亿元(人民币,下同),位居中国首位。公报显示,2013年,广东海洋灾害以风暴潮、海浪灾害为主,赤潮、海岸侵蚀、海水入侵与土壤盐渍化、咸潮入侵等灾害也均有不同程度发生。其中,发生风暴潮过程9次,造成直接经济损失累计约58.57亿元;海浪灾害共造成直接经     

赤潮灾害风险评估方法研究——以辽宁近岸海域为例

以赤潮灾害风险理论为依据,结合辽宁沿海城市近70年长期赤潮灾害历史资料数据,建立了辽宁近岸赤潮灾害风险评估指标体系,运用熵权法及层次分析法分析指标权重,构建了危险度指数、承灾体脆弱性指数灾害风险评价模型,最后,利用自然灾害风险分级矩阵方法进行灾害风险分级。风险评估结果显示,辽宁沿海城市大连市属于极高风险等级,丹东市、营口市、葫芦岛市属于中风险等级,盘锦市和锦州市处于较低风险等级。评价结果与近十年赤潮灾害历史统计数据基本吻合,该方法的建立对辽宁近岸海域赤潮灾害风险界定及防治具有重要意义。     

山东省渤海沿岸海域赤潮灾害与防治初探

<正> 一、赤潮的发生及危害1989年,我国沿海从南到北都有赤潮出现,不仅范围广,而且危害严重。1989年8月至9月,河北省沿海7县市近海发生了大面积赤潮,10万亩虾池不同程度受灾,养殖对虾减产1万吨,造成经济损失达2亿元以上。天津市海域赤潮灾害经济损失达4360万元以上。这次赤潮灾害也波及到山东省渤海     

海水赤潮的危害及防治对策

近几十年来,我国沿海赤潮灾害日益严重,严重危害着海洋渔业、近岸旅游业以及海洋经济的发展,同时也给人类健康带来严重威胁。赤潮生物的防治一直是人们关注的话题,本文对赤潮的危害及防治对策进行详细的阐述。     

加强海洋木质渔船建造与检验的管理确保安全生产

<正> 渔业船舶是从事渔业生产的重要生产工具和设备。如何保证建造的船只能达到国家颁发的《木质海洋渔船建造及检验规定》标准,一直是船检部门及造船单位不断探讨的问题。1 乐亭县海岸线长达49km,从事海洋渔业生产的船只1511艘,直接从事渔业生产的劳力约1.2万人。海洋捕捞生产总值1993年为3980万元,是我省海洋捕捞生产的大县之一。随着水产品价格的放开和大幅度的提高,     

有害赤潮藻对鱼类影响的研究进展

赤潮灾害的多发性和普遍性极大危害了海产养殖业和渔业资源,严重破坏了正常的海洋生态系统,直接威胁着人类的生存环境和健康水平[1,2]。在赤潮灾害中,鱼类的大量死亡带来的危害和损失占相当大的比重[3],在我国,1998年春季南海的一次特大赤潮造成了大规模的养殖鱼死亡,直接经济损失超过3亿元。在这类赤潮灾害中不仅渔业资源和鱼类养殖业遭受了极大的破坏,海洋生物的种群结构乃至整个海洋生态系统也受到了影响,毒素在鱼类体内的累积威胁着食用者的生命安全[4]。因此,科学家们针对有害赤潮藻及其毒素对鱼类的影响开展了一些调查和研究工作…     

青岛近海赤潮灾害分级与时空分布及赤潮生物的变化

根据赤潮发生面积和赤潮藻类的危害类型,将青岛近海发生的赤潮划分为特大、重度、中度、轻度和轻微共计5个灾害级别。结果表明,1990-2013年青岛近海共计发生赤潮33次,以轻微灾害和轻度灾害为主,其它级别尚未发生;其中,发生面积小于10 km2赤潮占总数的51.5%,60.6%的赤潮由基本无害的赤潮种类引起,发生范围以胶州湾和浮山湾近海为主;赤潮次数和面积基本呈现4~5年的波动周期,高发期集中在每年的6-8月;主要赤潮生物种类是红色中缢虫(Mesodinium rubrum)和夜光虫(Noctiluca scintillans);引发赤潮的生物种类逐渐增多,甲藻比例升高,罕见种类逐渐出现。赤潮种类的变化反映出青岛近海浮游植物的种类组成发生了改变,与期间青岛近岸海洋环境的变化密切相关。     

天津沿海遭受风暴潮袭击海洋渔业损失较大

2003年10月10、11日二天,由于受大风、暴雨、天文大潮的影响,天津市沿海部分渔船、养殖池塘、滩涂贝类资源遭到不同程度的破坏,部分渔民生产生活受到影响,初步统计直接经济损失3639万元,其中:捕捞渔船受损156艘,一人失踪,经济损失1000万元;地撩网大部分被冲毁,经济损失144万元;养殖池塘被冲毁18010亩,经济损失2495万元。受灾害破坏严重的汉沽区营城镇被撞毁渔船106艘,造成经济损失1220万元,有的渔船进水沉没,有的被撞损,同时,全镇被冲毁的养殖虾池有1650亩,造成经济损失1151万元。塘沽区北塘渔民协会所属津塘渔03307渔船在新港东突堤港池内…     

赤潮对沿海渔业的影响与防治对策

随着近海局部海域环境条件的变化，海水中某些微小生物在短时间内突发性繁殖，而形成赤潮。近年来赤潮发生频率逐年增多。其中1998年-2002年的5年间发生赤潮221起。而2007年我国海域发生赤潮82次，累计发生面积约11610km^2，因赤潮造成的直接经济损6000万元。这些赤潮多数发生在近海港湾、给沿海渔民带来巨大的经济损失。广东近年来对水域环境进行不少保护措施，但近海水环境并不乐观。因此，为了确保海洋渔业减少损失，我们要了解赤潮形成原因，对渔业的影响，及防范措施，采取有效的对策，尽量减少对国民经济和人民健康生活不必要的损失。     

Economic impact of juvenile fishing in a tropical multi-gear multi-species fishery

In open access marine fisheries, the non-targeted catches in the form of juveniles are detrimental, as this would reduce future yield and subsequent recruitment to the fishery. The proliferating impact of juvenile fishing is much more intense in a multi-gear multi-species fishery like Indian marine fisheries, where intra- and inter-sectoral conflicts exist. Marine fishing in India is contributing significantly to the country's economic growth and the coastal livelihood security. Although the recent changes in the techno-harvesting pattern of inshore fisheries of the country has led to a remarkable increase in fish landings, the problem of by-catch and targeted juvenile fishing is ever increasing. The present analysis shows that the contribution in the form of annual average profit by various craft–gear combinations is often not sufficient to compensate the overall loss generated by the same to the fishery through the harvest of juvenile fishes. Even though the fishermen gain some transient economic incentives from the juveniles landed, the estimated economic loss calculated was at about US$ 19,445 million year⁻¹ from the mechanised as well as motorised sector. Both intergenerational and conventional discounting was applied to show the net present value (NPV) of future loss due to juvenile fishing. Some of the less capital intensive gears also substantially contribute towards the economic deficit caused by juvenile fishing. We suggest that, while considering the ecosystem impacts of accidental by-catch and intentional juvenile fishing, the economic impacts also should be taken into account prior to formulating any management measures. The study provides an insight to the cost of juvenile fishing in a multi-species multi-gear fishery, where a homogeneous management system is ineffective. The possible causes of increased growth overfishing in the country and subsequent economic loss to the industry are also discussed.     

Growth overfishing in the brown shrimp fishery of Texas, Louisiana, and adjoining Gulf of Mexico EEZ

Growth overfishing in the brown shrimp, Farfantepenaeus aztecus, fishery in inshore (estuarine) and offshore (Gulf of Mexico) territorial waters of Texas and Louisiana, and adjoining waters of the United States’ (U.S.) Exclusive Economic Zone (EEZ), and its potentially detrimental economic consequences to the harvesting sector, have not been among major concerns of Federal and State shrimp management agencies. Three possible reasons include (1) environmentally influenced variations in recruitment that cause wide fluctuations in annual landings, which tend to obscure effects of fishing, (2) competition between inshore and offshore components of the harvesting sector, and (3) partitioning of management jurisdiction among a Federal council and two State agencies. Wide variations in landings led to beliefs that high levels of fishing mortality were tolerable and recruitment overfishing was of no major concern. This encouraged somewhat laissez-faire management approaches that allowed fishing effort to increase over the years.Our objectives were to determine whether growth overfishing occurred in this fishery during 1960–2006, and whether and how decreases in size of shrimp within the landings, in response to increases in fishing effort, affected inflation-adjusted annual (calendar year) ex-vessel value of the landings, i.e., their value to the harvesting sector. Growth overfishing occurred in the early 1990s, and then abated as fishing effort declined due to rising fuel costs and competition from imported shrimp. However, inflation-adjusted annual ex-vessel value of the landings peaked in 1985, prior to growth overfishing.Management actions implemented in 2001 for Texas’ territorial waters, and in the EEZ off Texas and Louisiana in 2006, should limit future fleet expansion and increases in fishing effort, thereby reducing the chances of growth overfishing and its potentially detrimental economic impacts on the harvesting sector. Growth overfishing should be included among the guidelines for future management of this brown shrimp fishery.     

山东半岛沿海渔民转产转业的路径选择

近年来，由于我国近海渔业资源不足与捕捞力量过剩之间的矛盾，山东半岛沿海渔民转产转业问题越来越受到关注。文章依据山东半岛渔业及相关产业的发展特点和规律，对山东半岛沿海渔民转产转业的路径进行探讨和分析，提出以海水养殖业、水产加工业、滨海旅游业、休闲渔业等传统和新兴产业为主的路径选择。同时结合实际提出了实现山东半岛渔民转产转业的四项关键措施。     

Contribution of marine fisheries to worldwide employment

Marine fisheries contribute to the global economy, from the catching of fish through to the provision of support services for the fishing industry. General lack of data and uncertainty about the level of employment in marine fisheries can lead to underestimation of fishing effort and hence over‐exploited fisheries, or result in inaccurate projections of economic and societal costs and benefits. To address this gap, a database of marine fisheries employment for 144 coastal nations was compiled. Gaps in employment data that emerged were filled using a Monte Carlo approach to estimate the number of direct and indirect fisheries jobs. We focused on estimating jobs in the small‐scale fishing sector. We characterized small‐scale fishing as (i) primarily geared towards household consumption or sale at the local level; (ii) conducted at a low level of economic activity; (iii) minimally mechanized; (iv) conducted within inshore areas; (v) minimally managed; and/or (vi) undertaken for cultural or ceremonial purposes. In total, we estimated that 260 ± 6 million people are involved in global marine fisheries, encompassing full‐time and part‐time jobs in the direct and indirect sectors, with 22 ± 0.45 million of those being small‐scale fishers. This is equivalent to 203 ± 34 million full‐time equivalent jobs. Study results can be used to improve management decision making and highlight the need to improve monitoring and reporting of the number of people employed in marine fisheries globally.     

TECHNOLOGICAL ADAPTATION TO HARMFUL ALGAL BLOOMS: SOCIOECONOMIC CONSEQUENCES FOR THE SHELLFISH FARMING SECTOR IN BOURGNEUF BAY (FRANCE)

The economic impacts of harmful algal blooms (HABs) on the shellfish farming sector depend on their frequency, duration and intensity. Safeguarding storage and accelerated detoxification are technical solutions that could mitigate the effects of these events. This article first analyzes the economic feasibility of the technological changes that can be adopted by the shellfish farming sector in France. It then examines their associated social impacts. Finally, an application is carried out on the Bourgneuf Bay production area. The economic analysis addresses three issues related to HABs: (1) the economic performance of the shellfish farms in Bourgneuf Bay, (2) the costs of these new technologies, and (3) the economic viability of such an investment. Results suggest that only a few economically viable farms would be able to implement these technologies, yet this would not be an option for smaller, less profitable farms. Individual action within the context of a “laissez-faire” public policy, taking into account the need for technological equipment, would result in a concentration of the sector to the benefit of the largest capitalist farms, with negative effects on employment and the distribution of economic rent. Alternative ways for implementing these technological changes would require collective actions or public support.     

Port location for inshore fleets affects the sustainability of coastal source–sink resources: Implications for spatial management of metapopulations

This paper focuses on the consequences of a geographical differentiation in reproductive potential through a species range not being recognized in the management of a coastal fishery resource. A dynamic spatial model with age-structure and bioeconomic components was built to explore the potential effects of fishing port location on metapopulations with a source–sink structure. Management of this type of fishery using marine protected areas (MPA) with or without considering the location of source and sink components is also addressed. An array of unit areas for a multi-age semi-sedentary resource was fed with recruits generated by a Beverton–Holt spawner–recruit relationship driven by the adult biomass in a source area. This contributes recruits both to source areas, and adjacent sink areas which do not produce recruits. Recruits are allocated to unit areas in the array according to a negative binomial distribution, allowing age structures to build up in each. Exploitation is from one of two ports, either situated close to the source area or distant from it; it being assumed (as for inshore fleets) that distance traveled is a key variable. Effort exerted per unit area is therefore determined by dynamic site-specific profits. Because fishing costs increase with distance, the alternative port locations are predicted to have substantially different impacts on biological and economic performance variables when there are no spatial management measures in place. Closing half the source area to fishing mitigates substantially the effect of port location, and improves all performance variables regardless of port location. The greatest positive impacts of a closure occur where the main port harvesting the resource is the one nearest the source area being protected.

When a spatial closure is applied, the average distance harvesters travel from a port close to the source is predicted to increase for all levels of fishing intensity, while distances traveled by fishermen from a port near the sink areas are predicted to decrease. If an MPA is established outside the source area, it is predicted to result in deteriorating production and net revenues because fishing intensity will tend to increase in the unrestricted source area.     

Response of benthic fauna to experimental bottom fishing: A global meta‐analysis

Bottom‐contact fishing gears are globally the most widespread anthropogenic sources of direct disturbance to the seabed and associated biota. Managing these fishing disturbances requires quantification of gear impacts on biota and the rate of recovery following disturbance. We undertook a systematic review and meta‐analysis of 122 experiments on the effects‐of‐bottom fishing to quantify the removal of benthos in the path of the fishing gear and to estimate rates of recovery following disturbance. A gear pass reduced benthic invertebrate abundance by 26% and species richness by 19%. The effect was strongly gear‐specific, with gears that penetrate deeper into the sediment having a significantly larger impact than those that penetrate less. Sediment composition (% mud and presence of biogenic habitat) and the history of fishing disturbance prior to an experimental fishing event were also important predictors of depletion, with communities in areas that were not previously fished, predominantly muddy or biogenic habitats being more strongly affected by fishing. Sessile and low mobility biota with longer life‐spans such as sponges, soft corals and bivalves took much longer to recover after fishing (>3 year) than mobile biota with shorter life‐spans such as polychaetes and malacostracans (<1 year). This meta‐analysis provides insights into the dynamics of recovery. Our estimates of depletion along with estimates of recovery rates and large‐scale, high‐resolution maps of fishing frequency and habitat will support more rigorous assessment of the environmental impacts of bottom‐contact gears, thus supporting better informed choices in trade‐offs between environmental impacts and fish production.     

传统捕鱼权与专属经济区制度

根据1958年通过的《领海及毗连区公约》和1982年通过的《联合国海洋法公约》确立的领海制度,沿海国在其领海内享有专属捕鱼权。在20世纪80年代以前,经过国际社会的长期讨论与实践,传统捕鱼权得到了多数沿海国的认可与尊重,即沿海国在其专属渔区或管辖范围内拥有优先权,而其他国家在其国民长期以来惯常捕鱼的区域享有继续捕鱼的权利。但是,1982年《联合国海洋法公约》确立的专属经济区制度却否定了其他国家的国民在沿海国专属渔区或管辖范围内享有的传统捕鱼权。鉴于传统捕鱼权在专属经济区中的地位,当我国与有关国家进行东、黄海海域划界时,应强调地质、地貌、海岸线的长度、渔业资源的合理保护和对渔业资源的公平利用等,特别是经济因素,以争取合理的利益。     

Catching industrial fishing incursions into inshore waters of Africa from space

Small‐scale fisheries contribute substantially to the sustainability of coastal communities by providing livelihood and economic opportunities and ensuring food security. However, their geographic range of operation overlaps with that of industrial fisheries, increasing the resource competition, risk of vessel collision and inter‐sector conflicts, while jeopardizing the sustainability of fish stocks. When industrial vessels venture into waters that are reserved to artisanal fisheries, their operations become illegal. In Africa, the extent of such operations, beyond their legal implications, has resulted in severe economic, food security and maritime safety issues. In this paper, we use automatic identification system data derived from satellite technology to predict fishing operations and find that industrial fleets spend 3%–6% of their time fishing within inshore areas reserved for small‐scale fisheries between 2012 and 2016, of the total 4.2 million industrial fishing hours within the Exclusive Economic Zones of African countries. We assessed the total fishing effort by this form of illegal fishing operations at 166 million kWhours at least out of 4.9 billion kWhours in total. We discuss this dangerous form of illegal fishing, which often results in deadly collisions with small‐scale sector operators, increases competition and conflicts over fisheries access, threatens the sustainability of fish stocks, and calls for better governance, and protection.