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41.
In response to fisheries decline in the Mexican Caribbean and continuing deterioration of the Mesoamerican Reef, conservation NGOs have begun to negotiate and collaboratively design a network of no-take zones (NTZs) with three fishing cooperatives in the Sian Ka’an Biosphere Reserve (SKBR), among other places along the coast of Quintana Roo. Spiny lobster (Panulirus argus) is the target of the main fishery within cooperative concessions. Fishers are uniquely positioned to enforce and monitor NTZs and evaluate their effectiveness. This study analyzes fishers' perceptions as indicators of social acceptance of NTZs, and identifies facilitating factors and challenges of the community-based process. Consistent with similar studies, responses of fishers (89 out of a population of 124) to a semi-structured interview showed that perceptions of NTZs largely reflect fishers' concerns and interests. A high proportion of fishers accurately identified main NTZ objectives of regulation, conservation and economic improvement, as well as NTZ locations. Further, fishers cared about ecosystem sustainability and, because NTZs would not significantly limit their main economic activity, endorsed the initiative while expecting additional benefits. Declining trends in lobster catch influenced a perceived need for NTZs. Major concerns were that illegal fishers would reap NTZ benefits and that economic impacts and benefits were uncertain. Most fishers found the decision-making process inclusive, were willing to take responsibility for enforcing NTZs and believed people leading the process were trustworthy. Differences in endorsement of NTZs among cooperatives points to the importance of understanding fishers’ incentives to collaborate, and the leadership and organizational dynamics which shape participatory processes. This analysis highlights challenges in advancing NTZs in complex ecological, socio-economic and regulatory contexts. It underscores the need for community-based processes that transcend understanding of conservation measures but also invests in sustainable, operative and trustful working relationships, as well as the urgency of interdisciplinary approaches in ensuring effective design and implementation of this relatively new fishery management tool.  相似文献   
42.
【目的】调查了解镇江豚类保护区鱼类资源状况,丰富鱼类资源本底数据。【方法】于2013、2016和2019年,分别开展3次渔业资源调查,对该区域鱼类种类组成、优势种、体型大小及群落多样性进行统计分析。【结果】共记录鱼类68种属于7目13科47属;鲤形目(Cypriniformes)鱼类种类占比较为稳定,鲇形目(Siluriformes)鱼类资源量有下降趋势,鲈形目(Siluriformes)鱼类种类占比上升明显;不同年份优势种替代较为明显;2016年的物种丰富度指数和多样性指数最高,分别为6.528、3.026。【结论】保护区鱼类资源较为丰富,但不同年份鱼类群落变化较为明显,渔业资源面临小型化趋势。  相似文献   
43.
44.
A large artisanal fleet made up of small-sized vessels fishes along the Galician coastline using passive gear and traps. The aim of this study is to analyse the economic profitability of this fleet in the last 5 years by looking at the average rate of return on the vessel and the investment payback period. The results show a slight drop in the return per vessel half-way through the period studied caused by the effects of the Prestige oil spill, to quickly recover over the following 2 years. Considerably high profitability rates from fishing activity were observed, especially in the second half of the period, and slightly lower payback periods, in general, than the average life of a standard fleet vessel.  相似文献   
45.
Collection of marine invertebrates for use as fishing bait is a substantial activity in many parts of the world, often with unknown ecological consequences. As new fisheries develop, it is critical for environmental managers to have high quality ecological information regarding the potential impacts, in order to develop sound management strategies. Crab-tiling is a largely unregulated and un-researched fishery, which operates commercially in the south-west UK. The target species is the green crab Carcinus maenas. Those crabs which are pre-ecdysis and have a carapace width greater than 40 mm are collected to be sold to recreational anglers as bait. Collection involves laying artificial structures on intertidal sandflats and mudflats in estuaries. Crabs use these structures as refugia and are collected during low tide. However, the effect that this fishery has on populations of C. maenas is not known. The impact of crab-tiling on C. maenas population structure was determined by sampling crabs from tiled estuaries and non-tiled estuaries using baited drop-nets. A spatially and temporarily replicated, balanced design was used to compare crab abundance, sizes and sex ratios between estuaries. Typically, fisheries are associated with a reduction in the abundance of the target species. Crab-tiling, however, significantly increased C. maenas abundance. This was thought to be a result of the extra habitat in tiled estuaries, which probably provides protection from natural predators, such as birds and fish. Although crabs were more abundant in tiled estuaries than non-tiled estuaries, the overall percentage of reproductively active crabs in non-tiled estuaries was greater than in tiled estuaries. As with most exploited fisheries stocks, crabs in exploited (tiled) estuaries tended to be smaller, with a modal carapace width of 20–29 mm rather than 30–39 mm in non-tiled estuaries. The sex ratio of crabs however; was not significantly different between tiled and non-tiled estuaries. These results illustrate the potential to manage fished populations using habitat provision to mitigate the effects of fishing pressure.  相似文献   
46.
随着渔业经济的发展,捕捞强度过大使得渔业资源严熏衰退,渔村社区面临转型的困境。以调查村为例从产业结构、管理体制、文化教育管理、生活方式等四个方面对其现实的状况与困境进行分析,并在此基础上提出转型的相应对策措施,以期为相关政府部门的决策提供参考和借鉴。  相似文献   
47.
随着渔业经济的发展,捕捞强度过大使得渔业资源严重衰退,渔村社区面临转型的困境.以调查村为例从产业结构、管理体制、文化教育管理、生活方式等四个方面对其现实的状况与困境进行分析,并在此基础上提出转型的相应对策措施,以期为相关政府部门的决策提供参考和借鉴.  相似文献   
48.
In this study we examine physiological responses of Peruvian hake (Merluccius gayi peruanus) to changes in their population structure and physical environment during the period 1971–2004. In particular, we assess the relative investment of energy in growth and/or reproduction of small (20–35 cm) and large (35–50 cm) hake. We calculated the (i) condition (Fulton’s K), (ii) gonad and (iii) gut fullness indices for 42,761 female hakes sampled from commercial landings; these indices indicate fish somatic, reproductive and feeding condition, respectively. Using Generalized Additive Models we then examined potential relationships between these indices and sea surface temperature anomalies and date. Drastic energy exhaustion and a decrease in female hake fecundity were observed during El Niño events. The long-term trend showed a general increase in condition factor and a decrease in gonad index for large hake between 1971 and 2004. Small hake exhibited a different trend with an increase in reproductive activity, which was accompanied by an earlier maturation. We hypothesise that the observed low investment of energy in reproduction by large female hake might be related to the lack of large males, due to a sex-selective fishery and the impact of El Niño. We suggest that fishing diminished hake reproductive capacity, modified the sex ratio in favour of females and increased population vulnerability to environmental stress, in particular to the El Niño. The impact of multidecadal variability and predators like the squid, Dosidicus gigas, remain unresolved until longer time series become available.  相似文献   
49.
根据长山群岛 1965-2016 年渔业统计资料,分析长山群岛海域主要捕捞渔获物产量、平均营养级 (Mean trophic level, MTL)、渔业均衡指数 (Fishing in balance index,FiB) 年际变化,探讨其海洋渔业资源利用状况,并利用小波分析方法研究52年来渔获物 MTL 周期变化特征。研究表明: (1) 长山群岛捕捞产量、MTL 和 FiB 指数呈阶段性变化; (2) 长山群岛渔业资源开发经历初期开发、扩张捕捞、过度捕捞、资源破坏等四个阶段,渔业资源环境正在逐渐恶化;(3) 受人类捕捞活动影响,MTL 在 15~19 年和 24~34 年两种时间尺度下呈周期波动,30 年为第一主周期,17 年为第二主周期。长山群岛渔业资源破坏日益严重,未来几年平均营养级将呈下降趋势。为防止渔业资源进一步衰退,应加强捕捞活动管理力度,落实海洋渔业资源保护制度;完善预警机制,构建海洋渔业资源监测系统;同时应积极调整长山群岛渔业产业结构,提高资源产出效率.  相似文献   
50.
人工鱼礁建设具有生态效果、经济效果和社会效果。为科学指导人工鱼礁的建设方向,进一步促进海洋牧场建设以及海洋渔业资源和海洋生态环境的可持续发展,文章采用改进的层次分析法,从人工鱼礁与社会的适应性、对社会环境的影响、对社会生活的影响以及对其他行业发展的影响4个方面,选取政策符合性等10个评价指标,通过问卷调查的方式,对南麂列岛海域人工鱼礁的社会效果进行评价,填补该研究领域的空白。研究结果表明:根据各评价指标的权重和效果判定值,南麂列岛海域人工鱼礁产生了较好的社会效果,其中海洋生态环境、项目长远性、改善渔民生活质量和海洋捕捞业等指标发挥作用较大;未来将开展长期和连续的调查研究,提高评价可信度。  相似文献   
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