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蓝点鲅渔业的最佳经济效果 总被引：3，自引：0，他引：3
蓝点鲅（Scomberocmorus Niphonius Cuvier & Valennes）是我国渔业的重要捕捞对象之一。本文用生物经济模式（基于 Schaefer 模式和 Fox 模式）讨论了蓝点鲅渔业的经济效益、能源消耗和就业等问题。对其最大经济效益(Umax)、最适能源消耗(Oopt)和最适经济捕捞努力量(foop)等数值作了估算,列于表2。如果以最大经济效益为这个渔业的管理目标,将捕捞努力量控制在最适经济捕捞努力量水平(foop 约为 290O),就能获得最大经济效益(Umax=19.65百万元)。把这个结果与最大持续产量的结果相比,渔业的经济效益将增加15.5%,能源消耗减少26.8%,但产量将下降7.2%,约2000吨。如果以增加就业为这个渔业的管理目标,捕捞努力量可控制在5400左右、和最大经济效益的结果相比,捕捞力量可多安排76.8%,但是渔业经济效益下降35.2%,能源消耗将增加78.9%。 相似文献
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闽东渔场渔业资源可持续产量和最适捕捞力量估算及近期捕捞结构和捕捞力量调整意见 总被引：1，自引：0，他引：1
本文根据1990—2000年水产统计资料和实地广泛收集闽东渔场定置网、拖网(含对拖、单拖)、流刺网和钓等四种作业的大量样本船，以各类样本船的平均功率计算闽东历年四种作业的总功率。应用数学模式估算出闽东渔场四种作业类型最大持续产量(May)和最适捕捞力量(fmay)，并提出闽东渔场近期捕捞结构和捕捞力量调整的意见。 相似文献
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利用2011年莱州湾中国对虾放流回捕生产调查统计和生物学测定数据,构建了包括资源模块、经济模块、决策模块的资源-经济模型,模拟了不同管理决策对放流经济效果的影响.结果表明,放流规模和捕捞强度不变时延迟开捕,总成本降低,渔民捕捞收益和社会经济效益先增加后减少,存在一个使放流经济效益达到最大值的最佳开捕日期：例如,当放流规模为738亿尾、捕捞死亡系数为0.03时,10月8日开捕可以获得最大的社会经济效益19.30万元;放流规模和开捕日期不变时扩大捕捞力量,总成本增加,同样存在一个最优捕捞规模使放流经济效益达到最大,但并非捕捞规模越大获得的经济收益越大;开捕日期和捕捞规模不变时,社会经济效益与放流规模成正比.在放流实践中,管理者应合理设置放流数量、捕捞规模和开捕日期,通过科学管控争取达到最佳的放流效果. 相似文献
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我们将模型Y/R=(?)用于研究秋汛对虾渔业不同的开捕期和捕捞死亡对世代相对产量(Y/R)的影响。根据渤海对虾渔业的实际情况,在限定捕捞死亡F_旬≤0.3(捕捞力量约相当于1,000对标准机帆船)的条件下,获得最大世代相对产量的最佳开捕期为9月21日。当前秋汛渤海对虾渔业的捕捞力量(约1,700—1,800对标准机帆船)太大,额外消耗能源和渔业经济效益很差。秋汛对虾渔业有明显的生长型捕捞过度的倾向。秋汛对虾渔业管理主要是开捕期与捕捞力量的管理和合理分配资源问题。限定虾流网、机帆船和机轮拖网三种主要网具的数量和它们的开捕期,是合理利用和分配资源的有效途径。 相似文献
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调整秋汛对虾渔业开捕期和捕捞力量，以获得世代最大产量，已有许多讨论。这是以一个简单生物项为秋汛对虾渔业的管理目标。生物项作为管理目标是不够的。它的内容，它的系统范围都太小，不能与广泛的社会利益相适应。在渔业管理决策时，必需要考虑经济与社会等有关的因素。包括渔业经济效益，能源消耗、就业等等内容。本文将讨论秋汛对虾渔业的最大经济效益等因素，提供一些科学证据，供决策参考。 相似文献
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本研究基于B-H模型创建了一种多鱼种管理方法,即把针对单鱼种的“开捕年龄”和“捕捞死亡系数”管理目标替换成面对多鱼种的“开捕网目尺寸”和“捕捞努力量”管理目标,从而实现多鱼种管理。利用文献参数,对东海两种主要经济鱼种带鱼和小黄鱼的综合管理进行了尝试和探讨。结果显示,带鱼和小黄鱼由于体型和个体大小差距较大,最适产量重叠范围较小,两个鱼种不适宜综合管理;可以针对不同渔场、不同专捕渔船进行单独管理。该模型具直观、易判、及时等优点;同时存在短期有效、要求体形相近等缺点。若要推广该模型,需要积累足够的基础数据以获取必要的模型参数;另外还需要探讨捕捞努力量标准化方法,进一步提高模型准确性。 相似文献
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本文根据1995—2007年水产统计资料和近期海洋捕捞作业结构，应用Schaefer和Fox数学模型得出汕头市拖、围可持续产量和最适捕捞力量，并提出汕头近海近期捕捞结构和捕捞力量调整意见。 相似文献
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应用营养动态模式和Cushing模式估算台湾海峡及其邻近海域渔业资源生产力分别为 3 0 6.0 9× 10 4t和3 0 3 .84× 10 4t;Gulland和最大持续产量Yms简单模式估算该海域的最大持续产量分别为 15 5 .0 6× 10 4t和 15 2 .4 9× 10 4t ;Schaefer和Fox剩余产量模式估算其最大持续产量分别为 187.0 8× 10 4t和 15 7.89× 10 4t,扣除非可捕群体后 ,实际为 15 9.0 2× 10 4t和 13 4 .2 1× 10 4t;估算以 1996年福建动力拖网渔船单位kW渔捞效率为标准的最适捕捞力量分别为 168.0 4× 10 4kW和 199.4 4× 10 4kW。 相似文献
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Villy Christensen 《Fish and Fisheries》2010,11(1):105-110
It has been generally accepted for more than half a century that the fishing sector stood to gain from managing fisheries at the effort level producing maximum economic yield (MEY) rather than at the higher effort level producing maximum sustainable yield (MSY). However, the acceptance is built on evaluating only the revenue and cost structure for the fishing fleet, not for the overall fishing sector including processing, distribution and marketing of fish products. Considering these links of the fish value chain moves the MEY-level closer to, but slightly below the MSY-level. For society as a whole, this means that MSY is the more appropriate target reference level. 相似文献
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The relationship between fishing methods, fisheries management and the estimation of maximum sustainable yield 总被引：2，自引：0，他引：2
Mark N Maunder 《Fish and Fisheries》2002,3(4):251-260
The allocation of effort among fishing gears is as important as controlling effort with respect to both sustainable yield and ecosystem management. Differences in age‐specific vulnerability to the fishing method can modify the maximum sustainable yield (MSY) that is obtainable from a fish stock. Different gears or methods are more or less selective for the species targeted, and MSY is rarely, if ever, attainable simultaneously for all species. The different fishing methods capture different types of nontarget species. Some methods will often be more profitable than others, and different user groups will prefer different methods. In many fisheries, it is unlikely that fishing can be limited to a single gear or method, so compromises among them will be required. Global MSY is discussed as a possible reference point for fisheries management. The yellowfin tuna fishery in the eastern Pacific Ocean (EPO) shows all the above characteristics and is used to illustrate effort allocation among fishing methods. 相似文献
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We examine the claim in Christensen that Maximum Economic Yield (MEY) is equal to Maximum Sustainable Yield (MSY). The basis for this claim is that MEY considers only the ‘catching’ of fish and that when the full value‐chain is considered; it is the MSY level that maximizes economic value. We argue that to maximize society’s benefit from a given sector of an economy, resources need to be allocated across all sectors such that additional net benefits from employing one more unit of society’s resources are equalized across all sectors of the economy. In this way, the opportunity cost of employing society’s resources across all economic sectors is minimized. In an economy where all resources are fully utilized, further value added in the value chain for fish is an additional cost and has the effect of reducing fishing effort and optimum yield rather than the opposite. In a less developed economy or a developed one in recession where all resources are not fully used, the multiplier effect could be important, and if it is high for fisheries it would be an argument to maximize sustainable yield and effort. We show, using current input‐output data, that this is not the case. Furthermore, from a simple principle of optimization, we know that to optimize a sector that consists of many segments through time, one has to optimize every portion of the chain through time. 相似文献
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绿鳍马面鲀资源评析与合理利用 总被引：17，自引：0，他引：17
本文依据1984年1—4月对1255尾绿鳍马面鲀的年龄观察资料，得到各年龄的平均体长和相应的平均体重，求得生长参数，并根据最高年龄求得其自然死亡系数，还根据该种群的生长参数和自然死亡系数，用Ricker模式进行评析，估算出绿鳍马面鲀渔业的最佳捕捞水平和最佳开捕年龄。同时，根据1977—1985年的渔业统计资料，以机轮拖网投网次数为标准捕捞努力量单位，运用Schaefer模式，对绿鳍马面鲀渔业进行评析，求得其最大持续产量MSY和其相应的捕捞努力量水平ASY。据此估测，作者认为目前绿鳍马面鲀的利用已达较充分的程度，近两年有捕捞过度的趋势。为此，作者提出应降低目前的捕捞水平和推迟开捕年龄等具体建议。 相似文献
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闽南地区近海定置,拖,围网渔业最适捕捞力量及其管理措施 总被引：2，自引：0，他引：2
采用 Schaefer 剩余产量模式估算了闽南近海三大作业——定置网、拖网和灯光围网的渔业资源可捕量和最适捕捞力量,结果定置网的 MSY为5.55万 t,f_(opt)为33745张;拖网的 MSY 为15.92万 t,f_(opt)为2222艘;灯光围网的 MSY 为10.12万 t,f_(opt)为472组。根据评估结果就现有捕捞船(网)数量,提出了削减定置网和拖网作业的捕捞力量,发展灯光围网渔船的调整方案,以及合理利用和科学管理近海渔业资源的具体措施。 相似文献
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闽东渔场鱼类资源生态容量和最大可持续开发量 总被引：6，自引：1，他引：5
以海洋生态系统营养动力学为理论依据,根据历次调查所获得的闽东渔场初级生产力资料,通过对该渔场浮游植物有机碳含量和生态效率的测算、52种主要鱼类营养级及其有机碳含量的检测,采用营养动态模型和Cushing模型估算鱼类资源生态容量(自然生产量),采用Cadima模式和MSY简单模式估算鱼类资源最大可持续开发量。估算结果:闽东渔场鱼类资源生态容量平均为6.308×10~5t,最大可持续开发量为3.268×10~5t。1994年以来闽东渔场实际年渔获量3.435～4.685×10~5t,平均4.267×10~5t,已连续9年超过鱼类资源最大可持续开发量,呈现过度捕捞态势。必须实行渔获量负增长制度才能使鱼类资源得到有效恢复。 相似文献
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Policy needs to improve marine capture fisheries management and to define a role for marine protected areas in Indonesia 总被引：2，自引：0，他引：2
P. J. MOUS J. S. PET Z. ARIFIN R. DJOHANI M. V. ERDMANN A. HALIM M. KNIGHT L. PET-SOEDE & G. WIADNYA 《Fisheries Management and Ecology》2005,12(4):259-268
Abstract Management of Indonesia's marine capture fisheries faces a huge dilemma: evidence suggests that most, if not all, of Indonesia's capture fisheries are fully or overexploited, but the fishery sector is still expected to contribute to the increase of Indonesia's gross national product (GNP) through an increase in total catches. Furthermore, the current practice of using catch-effort data and Maximum Sustainable Yield (MSY) models to inform Indonesia's fisheries policies is flawed, putting sustainability and long-term profitability of Indonesia's fisheries at risk. It is argued that the following shift in capture fisheries management policy must be achieved to ensure the survival of Indonesia's fish stocks and fisheries:
1 a shift in fisheries policy from development-oriented management towards management for sustainability;
2 acceptance by fisheries managers that 'untapped resources' may not exist or cannot be exploited profitably;
3 acceptance by fisheries managers that any transfer of fishing effort between fishing grounds may contribute to collapse of local fisheries;
4 a shift in fisheries management from MSY models to eco-system based management, wherein Marine Protected Areas should play an important role. 相似文献
1 a shift in fisheries policy from development-oriented management towards management for sustainability;
2 acceptance by fisheries managers that 'untapped resources' may not exist or cannot be exploited profitably;
3 acceptance by fisheries managers that any transfer of fishing effort between fishing grounds may contribute to collapse of local fisheries;
4 a shift in fisheries management from MSY models to eco-system based management, wherein Marine Protected Areas should play an important role. 相似文献