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1.
Chih-Shin Chen 《Marine Policy》2012,36(3):623-629
Precious corals have been commercially exploited because of their legendary and cultural importance for many centuries in the Mediterranean and for almost one century in the Northwest Pacific. Although the precious coral fishery in Taiwan dates back to the 1920s, relevant studies on biology and ecology of resources are relatively scarce. The management of the precious coral fishery in Taiwan was officially instituted in January 2009, when data on the catch and effort of the fishery were recorded. In this study, the catch-effort data of the fishery were examined to explore the temporal and spatial patterns in composition and abundance of Corallium and Paracorallium spp. around Taiwan. A total landing of 3233.0 and 2906.8 kg precious corals were recorded for 2009 and 2010, respectively. Less than 5% of those amounts were from live colonies. A high proportion of fossilized colonies in the catch reflect the non-selective nature of the fishing gear; however, the factors that cause colonies to collapse are not exclusive to the impact of the fishery. Momo coral was dominant in the production for both years, followed by Miss coral. The total production of precious corals correlated positively with fishing efforts, while a weak relationship was found between the production of live colonies and fishing efforts. The fishing efforts mainly aggregated in designated fishing ground A (DFG-A) for both years, while the production of live colonies mainly occurred in DFG-E. The monthly occurrence rate of live colonies decreased over the past 2 years. Although fluctuating significantly, the CPUE of dominant species exhibited an apparent decreasing pattern. High aggregation of the fishing efforts in specific regions and low numbers of live colonies in the production should be carefully taken into account when amending management regulations in the future. The establishment of marine protected areas, in addition to the strict controls that already apply, should be considered to not only sustain the population structure of the sessile animals but also their function in the marine ecosystem. 相似文献
2.
《Marine Policy》2013
Precious corals (Coralliidae) have been a part of numerous aspects of human life and culture for several millennia. They differ from reef-building corals and primarily inhabit deep waters. Their characteristics of a slow renewal rate and high commercial value make them a frangible resource that is easily overexploited. Proposals to manage the main species with high commercial value through trade controls and listing in Appendix II were submitted to the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) in 2007 and 2010. Two of the main arguments for the northern Pacific precious coral CITES proposal were the more than 60–80% decline of Corallium secundum and C. sp. nov. in landings since 1980s and lack of proper management. Although both proposals were rejected, they have sparked debates regarding the benefits of managing coral resources through trade controls and fisheries management. In this study, several arguments related to this topic on northern Pacific precious corals are presented, in the following three dimensions: (1) a reconstructed historical landing series from official FAO data and information on the history of coral fishing have scientifically indicated that the substantial decline in landings in the late 1980s was caused by the abandonment of fishing grounds and a shift in the target species; (2) enhanced management plans, which incorporate effective monitoring, control, and surveillance (MCS) measures, have been implemented in the two main countries that fish precious coral; and (3) the influence of socioeconomic factors must be considered when assessing CITES listing applications. Recommendations for achieving sustainable coral resource conservation are also provided. 相似文献
3.
当前,对渔业资源评估模型的诊断与选择,主要依赖于模型对观察数据的拟合度,很少评价模型的预测能力、并将其作为评价渔业资源评估与管理质量的依据。为此,本文利用后向预报方法评价了印度洋黄鳍金枪鱼(Thunnus albacores)资源评估模型的预测能力,并在此基础上分析了印度洋黄鳍金枪鱼的资源评估与管理质量。研究表明,在利用贝叶斯剩余产量模型对印度洋黄鳍金枪鱼进行资源评估时,存在如下问题:(1)拟合较好的模型其预测能力较差;(2)利用不同时段数据拟合模型时,采用DIC(Deviance Information Criterion)选择的最佳模型缺少稳定性;(3)不同模型估计的TAC (Total Allowable Catch)存在较大差异。据此可以判断,利用贝叶斯剩余产量模型对印度洋黄鳍金枪鱼进行资源评估与管理效果较差。本研究结果表明:(1)利用后向预报方法可评价模型的预测能力、DIC选择模型的稳定性,从而能在一定程度上判断模型模拟的种群演化动态是否正确、资源评估结果是否存在问题;(2)利用后向预报方法可揭示评估结果的不确定性及其可能引起的渔业管理风险,从而有利于避免渔业管理风险、实现渔业管理目标。 相似文献
4.
《Marine Policy》2013
Many conventional management strategies have been demonstrated to be ineffective in achieving sustainable fisheries, and new approaches are required to overcome existing environmental, social and economic problems. Adaptive co-management represents the combination of a learning-by-doing approach (adaptive management) involving all related and legitimate stakeholders in the decision-making process (collaborative management). In this study, the relevant experiences from a fishery in southern Brazil are reported. The first section of the paper summarizes the broad history of national fisheries and their management. Then the southern Brazilian artisanal penaeid-trawl fishery is briefly described and the three main problems associated with the common gears used are discussed, including their (1) poor size and species selectivities, (2) poor efficiencies, and (3) their mechanical impacts on benthic habitats. Finally, a framework is proposed to address the environmental and socio-economic issues in the fishery and its implementation discussed via an adaptive co-management approach. 相似文献
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6.
Barbara Calcinai Carlo Cerrano Nozomu Iwasaki & Giorgio Bavestrello 《Marine Ecology》2008,29(2):273-279
Precious corals represent peculiar substrata for several species of boring sponges that exploit their carbonatic scleraxis, strongly decreasing their commercial value. Here we describe a new species of the genus Alectona from Japan recorded in a colony of Paracorallium japonicum (Kishinouye, 1903). The spicular complement of the new species consists of diactinal spicules covered by mushroom-like tubercles, often modified into styloid forms, and fusiform amphiasters with two or sometimes four verticils, each generally made up of six short tubercled rays. A complete survey of the literature on boring sponges recorded in precious corals in the Mediterranean Sea and Pacific Ocean indicates that the species of the family Alectonidae are the most strictly associated to this kind of substratum. Their world distribution, in fact, partially or totally overlap that of their coral hosts. 相似文献
7.
随着人类活动对于海洋资源的过度开发,渔业资源的衰退趋势愈发显著。因此,渔业资源亟待科学合理的理论指导来保护和利用有限的渔业资源。Ecopath生态通道模型是一种研究生态系统特征与变化的经典模型,除了可用于分析生态系统结构与功能以及评估生态系统的成熟稳定程度外,该模型还可以评估物种的生态容量,为增殖放流活动等渔业资源提供保护措施,因此被广泛应用于渔业资源生态容量研究。本文综述了生态容量的概念以及目前国内研究生态容量的常见方法,对Ecopath模型的发展历史做了简要概述,介绍了模型的原理、建立、调试方法以及使用Ecopath模型评估物种生态容量的操作方法,随后对模型中的各项参数指标做了详细的介绍。本文根据Ecopath模型在我国渔业资源研究中的应用方向进行了分类讨论,并对我国当前基于Ecopath的水域生态容量研究进展进行了汇总,对比了不同类型生态系统之间生态特征参数的异同,重点归纳了不同水域生态系统下的物种生态容量评估研究,最后提出了模型的限制性以及发展前景。 相似文献
8.
《Marine Policy》2016
Catch shares, where annual catch limits are divided among individuals, communities or cooperatives, are a commonly used fisheries management strategy to increase profits and reduce overcapitalization. Usually these quota shares can be sold or leased, which is theorized to allow for greater utilization of fleet-wide quota. However, this catch-quota balancing may not be achieved in multispecies trawl fisheries where it is difficult to selectively target valuable species while avoiding overfished species. Two similar catch-share-managed, multispecies trawl fisheries were compared to evaluate whether catch shares lead to catch-quota balancing. The U.S. West Coast Groundfish fishery has several species with low total allowable catches (TACs) while the Canadian British Columbia Trawl fishery has comparatively higher TACs. Results indicate that the West Coast fishery had a statistically significant decrease in catch-quota ratios from 0.41 in the three years before catch shares to 0.29 in the three years after catch shares. In contrast, the BC fishery experience no statistically significant change in fishery-wide average catch-quota ratios, which were 0.70 in the three years before and 0.62 in the three years after catch shares. In the West Coast fishery, the risk of exceeding quotas for some species may be so high that fishers are unable to achieve high degrees of catch-quota balancing and instead focus on species that can be easily selected with changes in fishing behavior. Multispecies fisheries management has direct tradeoffs between maximizing yield and achieving conservation goals, and these results may highlight the tradeoff between rebuilding overfished species by reducing TACs, and the achievement of catch-quota balancing. 相似文献
9.
An Irish commercial fishery for orange roughy began in the Northeast Atlantic in 2001 with the assistance of government grants. The fishery began as an open access, non-quota fishery. The rapid boom and bust of many deep water fisheries was experienced. Landings peaked in 2002 and then dropped significantly the following year. Many vessels were forced out of the fishery due to high costs and rapidly declining stocks. By 2005 the fishery was largely closed. Applying a bioeconomic analysis, this paper shows why the fishery no longer exists and discusses both the external and opportunity costs of the fishery. A bioeconomic model is applied to the available data to assess the open access effort and harvest with and without government grant aid. The results suggest that in the absence of subsidies, deep water trawling would not have been viable. In addition to the financial costs such as high fuel consumption, there are also externalities associated with deep water trawling. Orange roughy is closely associated with deep water ecosystems such as seamounts and cold water corals. This paper examines the costs of damage to cold water corals. These costs include the loss of fish habitats and lost future use and preservation values. 相似文献
10.
In 1998 a management system based on individual transferable quota (ITQ) was introduced in the Tasmanian rock lobster fishery. This marked the continuation of a management trend that has favoured economic efficiency at the cost of reduced employment and greater restrictions on access to the fishery. The authors discuss management trends in the fishery in the context of Tasmania's history, and social and political characteristics, which it is argued, have shaped development of Tasmania's resource management culture. Implications for social equality, economic well-being and environmental sustainability are discussed. In conclusion the difficulty of reforming policy that has been shaped by vested interests and which establishes rent-seeking activity is considered. 相似文献
11.
HU Wenji YE Guanqiong LU Zhenbin DU Jianguo CHEN Mingru CHOU Loke Ming YANG Shengyun 《海洋学报(英文版)》2015,34(2):45-54
世界范围内,海洋渔业资源广泛面临着过度捕捞的压力.鱼类的不同生活史特征可表征不同的生活史对策,其变化可揭示鱼类种群对渔业捕捞压力的响应.台湾海峡及其邻近海域的主要渔场30多年来面临着过度捕捞的压力,导致了鱼类群落结构发生改变.本研究分析了该海域51种主要经济鱼类的生态参数,系统研究了其生活史特征及其变化.采用主成分分析法可将51种鱼类分成5个不同的生活史对策组,分组结果表明超过60%的鱼类被归纳入第5组,即近r对策组,且多为中上层鱼类.在此基础上收集相关历史数据,对其中25种经济鱼类进行生活史变化分析,讨论不同鱼类种群对渔业开发的响应.分析结果表明,在长期的渔业开发活动下多数鱼类表现出小型化、低龄化、早熟和生长率加快等趋势.此外,本研究计算了每种鱼类的开发率以进一步研究渔业捕捞压力对鱼类种群的影响,发现其中4种底层和近底层鱼类的生活史特征变化显著,提示某些物种可能对捕捞压力更敏感.本研究可为渔业管理和保护提供重要的科学依据. 相似文献
12.
《African Journal of Marine Science》2013,35(3):601-611
The sparid Dentex macrophthalmus is a widespread, important fishery species along most of the West African coast from southern Namibia to the Mediterranean. In southern Angola it is an important artisanal species targeted predominantly by handline fishers. A biological and fisheries study was conducted on this species in southern Angola between June 2008 and July 2009. It was the dominant species in the artisanal fishery, accounting for 99% of the sparids captured and 67% (by mass) of the total catch. The life history of D. macrophthalmus was characterised by slow growth (females: Lt = 309[1 ? e?0.06(t + 5.43)], males: Lt = 248[1 ? e?0.16(t ? 1.77)]), advanced age at maturity (females: 7.4 years, males: 6.0 years) and high longevity (females: 36 years, males: 38 years). The sex ratio was 1:1 male:female. The length- and age-frequency distributions and macroscopic observations suggested that the species is a late gonochorist. Males and females reached 50% maturity at 151 and 166 mm fork length respectively. Although individuals with ripe gonads were found during most of the year, the peak spawning period appeared to be in December and January. Despite a life history that renders D. macrophthal-mus vulnerable to overexploitation, only 38% of artisanal fishers noticed a decline in the catches of this species. Potential reasons for this include: technology creep; limited pressure on the juvenile portion of the stock as a result of late recruitment (above the length of 50% maturity); the ‘basin affect’, whereby depleted areas are reseeded by areas (e.g. deeper water) inaccessible to the linefishery; and a deep-water reserve of large individuals. It is recommended that precautionary management strategies be implemented until the age estimates are revised by the countries in which this species forms significant fisheries. 相似文献
13.
分析日本渔业协同组合的建立对日本渔业管理活动的改进,针对这种政府、渔业协同组合和渔民的行为选择结果能够达到相对均衡状态,并且能够有效弥补政府单一监管模式的不足的管理模式,本文从博弈论角度分析渔民、政府、渔业协同组合的行为选择依据,得出了渔业协会是政府有效监管的必要前提,进而对我国渔业管理提供很好的借鉴意义。 相似文献
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15.
In response to the shortcomings of the EU's Common Fisheries Policy, the European Commission has suggested regionalising fisheries management. Examples already exist of the more decentralised management of certain fisheries. Since 2007, the Commission has requested national eel management plans (EMPs) from all EU eel-fishing nations, giving national management bodies considerable freedom to develop their own EMPs. To examine the prerequisites for decentralisation, the Swedish EMP was chosen as a case. The European eel is critically endangered due to overfishing and environmental degradation. Analysis of the Swedish EMP reveals serious flaws: the conflict between the objectives of species and fishery preservation has not been clarified nor is the prioritisation clear. The plan has not been critically reviewed and alternative options are not considered. Though the basic data are uncertain, this uncertainty is viewed as support for not adopting any safety margin. Management is therefore directed towards mitigating the negative effects of fishing and other human activities rather than realising the conservation objective. The efficiency of the various protection measures is also disputable; for example, translocation is problematic, as translocated (i.e., stocked) eels display impaired navigational abilities. Another problematic aspect of this conservation strategy is the slow implementation of the EMP. In conclusion, this study emphasises the necessity of legal and social science as well as natural science research to evaluate the efficiency and implementation of fishery management. 相似文献
16.
南海鱼类生物多样性与区系分布 总被引：7，自引：0，他引：7
分析了南海鱼类生物多样性与区系分布的生态地理条件,鱼类生物多样性特征。校核整理了南海鱼类2 321种,分属于六鳃鲨等35目,以鲈形目占绝对优势(979种),并以珊瑚礁栖,典型暖水种的隆头鱼科为优势科(占117种),而蝴蝶鱼和石斑鱼分别达到34种、31种,列为优势属,从而构成南海富有潜势的群落结构。文中进一步论述了南海鱼类区系属于以印度-西太平洋为主体的区系特征。 相似文献
17.
小黄鱼是我国近海四种最重要的经济鱼类之一,在过去的几十年中小黄鱼种群及其两个地理亚种群经历了巨大的变化。小黄鱼的种群动力学研究,对于维持这一重要渔业的可持续管理是至关重要的。目前仅有的两个小黄鱼种群动力学模型只涵盖了较短的时间,且没有关注其空间差异。本文研究了1968年至2015年间黄渤海和东海小黄鱼的种群动力学模型,包含和不包含空间分层结构的两种贝叶斯模型被用于分析其种群动力学的大尺度空间异质性。本文分析了不同的假设,来研究小黄鱼种群动力学潜在的变化趋势。研究结果表明小黄鱼种群动力学特征具有明显的时间和空间变化。种群的增长速度从20世纪八十年代开始增加,而可捕系数从1981年到2015年增加了两倍多。与黄渤海亚种群相比,东海的小黄鱼亚种群生长速度更快,遭受的捕捞压力也更大。基于最大可持续产量MSY的参考点表明,无论是整个小黄鱼种群还是两个亚种群,近年来都有非常高的过度捕捞风险。因此我国小黄鱼的渔业管理急需更加保守的管理策略,同时考虑其地域差异。本文所用的方法可以应用于其他种类的资源评估和渔业管理,尤其是具有空间异质性和数据有限的种类。 相似文献
18.
Bernerd Fulanda Jun OhtomiElizabeth Mueni Edward Kimani 《Ocean & Coastal Management》2011,54(5):401-414
The present study assessed trends in resource-use, partitioning and management in the Ungwana Bay fishery, Kenya, using surplus production models. The fishery is one of East Africa’s important marine fisheries sustaining a bottom trawl commercial fishery and a resident-migrant artisanal fishery. Two models: Schaefer (1954) and Gulland and Fox (1975) were applied to catch-effort data over a 21-year period to model maximum sustainable yield (MSY) and optimal effort (fMSY) to examine the status of resource exploitation and provide reference points for sustainable management. In the artisanal fishery, model MSYs range from 392-446 t to 1283-1473 t for shrimps and fish respectively compared to mean annual landings of 60 t for shrimp and 758 t for fish. These landings represent <50% of the model MSYs suggesting under exploitation in the sub-sector. Moreover, current fishing effort applied stands at <0.5 fMSY. On the other hand, mean annual landings in bottom trawl commercial fishery, at about 330 t for shrimps and 583 t and fish represent about 90% of the model MSYs of 352-391 t and 499-602 t for shrimps and fish respectively. Therefore, the bottom trawl commercial fishery is likely under full exploitation. Similarly, the current effort is estimated at >0.7 fMSY. Resource management in the bay is faced with numerous problems including resource-use conflicts, poor economic conditions in artisanal fishery, poor legislation, and inadequate research augmented by poor reporting systems for catch-effort statistics. Thus, the fishery lacks clearly defined exploitation regimes. Fisheries research and assessment of the marine resources are important for sustainability of the fishery. Moreover, income diversification in the poverty ridden artisanal fishery would go a long way in addressing resource-use conflicts and use of deleterious fishing methods in the sub-sector. Borrowing from the successes of the Japanese community-based fisheries resource management (CBFRM) which has easily resolved numerous fisheries management issues in coastal small-scale commercial fisheries, and the beach management unit (BMU) system which has been applied to the artisanal fisheries of south coast Kenya with enormous benefits, it is envisaged that a hybrid CBFRM-BMU system presents the best approach to sustainable resource-use in the Ungwana Bay fishery. 相似文献
19.
本研究于2020年7月在大亚湾及大鹏半岛沿岸开展造礁石珊瑚的分布、覆盖率、死亡率、硬珊瑚补充量和物种多样性调查。结果表明：24个站位共发现造礁石珊瑚9科17属44种以及5个未定种,其中裸肋珊瑚科的种类最多,有7属27种,其次为鹿角珊瑚科和滨珊瑚科,均有2属6种;中央列岛沿岸造礁石珊瑚平均覆盖率为12.0%,三门岛沿岸平均覆盖率为12.9%,大鹏半岛沿岸平均覆盖率为5.2%;以坚实滨珊瑚（Porites solida）、翼形蔷薇珊瑚（Montipora peltiformis）、五边角蜂巢珊瑚（Favites pentagona）和多孔同星珊瑚（Plesiastrea versipora）等为优势种;造礁石珊瑚物种多样性较高。与历史数据相比,大亚湾及大鹏半岛沿岸造礁石珊瑚退化严重,活珊瑚覆盖率锐减,优势种由分支状珊瑚逐步转变为皮壳状或亚团块状珊瑚。此外,本研究构建了近岸造礁石珊瑚生态脆弱性评价体系,并对目前大亚湾及大鹏半岛沿岸造礁石珊瑚进行了生态脆弱性评价。结果显示,中央列岛、三门岛和大鹏半岛东侧海域造礁石珊瑚处于低或中脆弱状态;较场尾、杨梅坑、西冲和大鹏半岛西侧海域造礁石珊瑚处于高或很高脆弱状态,在环境压力影响下其受损可能性较高。在海水养殖、渔业捕捞、滨海旅游和船舶航行等日益频繁的人类活动下,大亚湾及大鹏半岛沿岸造礁石珊瑚整体处于中高脆弱状态,建议加强珊瑚礁监测,并采取相应的保护措施。 相似文献
20.
《African Journal of Marine Science》2013,35(1):33-42
The South African abalone Haliotis midae resource is widely perceived as being under threat of over-exploitation as a result of increased poaching. In this paper, reservations are expressed about using catch per unit effort as the sole index of abundance when assessing this fishery, particularly because of the highly aggregatory behaviour of the species. A fishery-independent survey has been initiated and is designed to provide relative indices of abundance with CVs of about 25% in most of the zones for which Total Allowable Catchs (TACs) are set annually for this fishery. However, it will take several years before this relative index matures to a time-series long enough to provide a usable basis for management. Through a series of simple simulation models, it is shown that calibration of the survey to provide values of biomass in absolute terms would greatly enhance the value of the dataset. The models show that, if sufficient precision (CV 50% or less) could bc achieved in such a calibration exercise, the potential for management benefit is improved substantially, even when using a relatively simple management procedure to set TACs. This improvement results from an enhanced ability to detect resource declines or increases at an early stage, as well as from decreasing the time period until the survey index becomes useful. Furthermore, the paper demonstrates that basic modelling techniques could usefully indicate which forms of adaptive management experiments would improve ability to manage the resource, mainly through estimation of the level of precision that would be required from those experiments. The results of this study are particularly applicable to fishing zones for which there are insufficient other data to perform a standard stock assessment. 相似文献