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1.
刺网选择性对鱼类表型性状的选择作用研究 总被引：2，自引：0，他引：2
本研究从刺网选择性对鱼类表型性状的影响入手,应用数值模拟方法,模拟了一个具有一定体长特征的鱼类种群,利用具有多项选择参数(曲线标准差σ,最适体长l0,选择性因素R0)的刺网曲线对其进行长期捕捞作用,并在去除捕捞的情况下探讨这种影响的稳定性。结果表明,刺网捕捞作业长期作用于鱼类种群,会对种群体长组成产生深远的影响,开发率(E)越大,效果越明显。当刺网最适捕捞体长与初始种群优势体长重合时(l0=15),造成种群体长分布峰值的分化;如果l0>15,则导致种群体长组成向小型化方向偏移;反之则会造成种群体长组成向大型化方向偏移;而且这种影响可能伴随遗传因素,具有不可逆性。 相似文献
2.
拖网选择性引起的鱼类表型性状选择差的初步研究 总被引：5，自引：0，他引：5
本文应用数值模拟的方法,研究了拖网选择性引起的鱼类表型性状(生长速率K、极限体长L∞、初次性成熟年龄Am)的选择差,通过假设不同的白噪音CV、自然死亡系数M、极限体长L∞、种群的样本大小Ss及网目尺寸Ms来估算鱼类表型性状的选择差在最大捕捞死亡系数逐渐加强时的变化情况。模拟结果表明捕捞死亡系数越大,造成的K、L∞、Am选择差也越大,并且Am的选择差增大的速率比K、L∞的小。白噪音越大,自然死亡系数越大,种群受捕捞影响产生的K、L∞、Am的选择差越大;极限体长的大小和种群的样本大小对K、L∞、Am的选择差的影响不大;网目尺寸越大,K、L∞、Am的选择差越小。随着最大捕捞死亡系数的增大,种群的生长速率变大,极限体长变小,初次性成熟年龄提前。表明了捕捞压力造成鱼类生存环境的变化,鱼类种群发生自适应进化响应,表现在表型性状的变化,且捕捞强度越大,环境差异越大,导致的表型性状选择差越大。 相似文献
3.
脂肪是原生质的组成成分之一，也是能量代谢的重要原料。鱼类对栖息环境条件变化的适应及其本身的各个生命阶段新陈代谢的变化，必然在脂肪的代谢上有所反映。
把鱼类含脂量的变化，作为一项生态-生理学指标与鱼类的生物学状况和环境条件联系起来，在渔业生物学研究中应用，已经取得了一些成果。近20年来，许多学者已经证明，鱼类含脂量的变化与鱼类的行动、成活率和数量变化等有着密切的关系，也是饵料保障的较好指标。而有关大黄鱼含脂量变化的研究，则至今尚未见有报道。
本文主要对大黄鱼肌肉和肝的含脂量的个体变化与季节变化进行一些分析，并对肥满系数与含脂量的关系，大黄鱼合理捕捞期等问题做了初步讨论。这将对渔业资源的合理利用以及种群生态学的研究提供资料。 相似文献
4.
根据已开发鱼类种群的自然死亡率（M）在鱼类资源评估中的重要作用,讨论了1种应用实际种群分析（VPA）（亦即世代分析方法）估算鱼类自然死亡率的方法.文中假设了捕捞努力量（E）已知和未知2种情况,并同时求出了其他种群参数,如可捕系数,补充量等.在蒙特卡罗模拟分析中,假设了4种模拟渔业（管理良好的渔业,掠夺式渔业,恢复性渔业和稳定性渔业）对该方法进行了验证.并将von-Bertalanffy生长方程（VBGF）引入VPA模型来估算鱼类的自然死亡率.当CV等于20%时,在4种模拟渔业中鱼类各龄自然死亡率（Ma）的EP均小于10%.在已知单位捕捞努力量渔获量数据时,计算北大西洋长鳍金枪鱼（Thunnus alalunga）的M等于0.119,这个结果比先前假定的值（0.3）小,但考虑到该鱼种所承受的高的捕捞压力作者认为该估计值是合理的. 相似文献
5.
东海捕虾桁拖网选择性能不佳,对渔业资源的保护和渔业的合理管理带来了负面的影响.刚性栅栏是实现拖网渔具种类选择性捕捞的主要装置,本文根据在吕四渔场开展刚性栅栏海上生产试验,结合SELECT模型分析不同栅条间距(15、20和25mm)的刚性栅栏对短吻舌鳎、小黄鱼和棘头梅童鱼的分隔效率.结果表明,随着栅条间距的增大,栅栏对鱼类的重量分隔率逐渐减小,分隔栅栏对鱼类的50%选择体长(L50S))逐渐增大;对于短吻舌鳎,个体接触分隔栅栏的概率可使用常数来表示,即接触概率与个体尺寸无关,接触概率在0.2-0.4之间,并随着栅条间距的增大而增大(不显著,P>0.05):对于小黄鱼和棘头梅童鱼,所有进入网囊的个体都将接触刚性栅栏;不同鱼类接触栅栏概率的显著差异说明不同鱼类在网囊中的不同行为习性. 相似文献
6.
黑脊倒刺喜巴（Spinibarbus caldwelli）是分布于中国南方各水系，具有重要经济价值鱼类。文中对来自赣江、九龙江、漓江等3水系的瑞金、长泰、桂林等3个黑脊倒刺喜巴种群共61个样品的线粒体DNA细胞色素b基因（mtDNA cyt b）进行PCR扩增和测序。对序列进行分析。结果发现，在全长（1141bp）cyt b共检测到45个变异位点，61个样品分属16个单倍型，与其它鲤科鱼类比较，黑脊倒刺钯的遗传多样性水平比较低。分子方差分析（AMOVA）及系统发育分析显示，瑞金和长求种群没有显著遗传差异，而它们与桂林种群存在显著遗传分化，提示黑脊倒刺啻巴可能存在多个地理种群。 相似文献
7.
基于生态系统的渔业管理的理念已得到广泛认同,但其在海洋牧场建设中的应用仍非常少见。本研究根据2020-2021年在蜈支洲岛海域开展的渔业资源底拖网调查数据,构建了海洋牧场鱼类群落的质量谱模型（SSM）,反映了海洋牧场中食物网的复杂结构以及种间相互作用,以评估捕捞对海洋牧场鱼类群落的影响。研究通过对两种管理策略（单物种管理和多物种管理）的模拟,分析特定种类的捕捞死亡系数变化对鱼类群落产生的影响,并利用群落总生物量、质量谱斜率、平均最大质量、平均质量和大型鱼类指数5种群落生态指标监测了鱼类群落的特征状态。单物种管理策略结果显示,蜈支洲岛海洋牧场生态系统呈现下行控制效应,肉食性鱼类对浮游生物食性鱼类存在着强烈的调控作用。捕捞死亡系数变化后,不同物种间竞争捕食等复杂的相互作用会产生营养级联效应。多物种管理策略结果显示,灰海鳗（Muraenesox cinereus）的捕捞死亡系数对群落质量谱斜率影响最大,大头狗母鱼（Trachiocephalus myops）和灰海鳗的捕捞死亡系数对鱼类群落生物量和群落结构及功能的影响最大。研究结果对于保护和维持鱼类群落稳定方面具有重要意义,能够帮助管理者更好... 相似文献
8.
浙江近海大黄鱼的季节生长 总被引：6，自引：1，他引：6
在自然环境的季节循环中,鱼类生长的季节周期性是阐明鱼类生物学特性变化的主要指标之一。大黄鱼 Pseudosciaena crocea(Rich.)是我国沿岸海区的主要捕捞对象;捕捞具有明显的季节性。因此,进行大黄鱼季节生长的研究,不仅可为合理利用资源、提高种群生产力等问题提供必要的生物学依据,而且对进一步探讨生长过程的规律,也具有重要意义。本文对浙江近海大黄鱼(春季生殖鱼群)的季节生长作一比较详细的分析;同时对季节生长的特点及其与耳石生长的关系进行了初步讨论。其次,对调整大黄鱼捕捞时期问题也提出了初步意见。 相似文献
9.
适用于短生命周期种类资源评估模型的研究现状与展望 总被引：1，自引：0，他引：1
《海洋湖沼通报》2015,(3)
近几十年来随着传统鱼类资源衰退,短生命周期种类的资源量和捕捞产量出现了增长,并已成为世界海洋捕捞业的重要捕捞对象,为使渔业资源可持续利用,必须制定合理的渔业管理计划,实现对渔业资源的科学管理。对渔业资源进行科学的评估是制定渔业管理计划的基础,渔业资源评估模型则是进行渔业资源评估的重要工具,对短生命周期种类资源进行科学评估和管理是一个极为重要的课题。但是短生命周期种类具有生命周期短、生长快、资源丰富以及产卵种群多的特点,资源量极易受海洋环境影响的独特的生活史特征,使得世界各国对短生命周期种类资源评估和管理的研究处在发展初期。本文首先介绍了短生命周期种类的生物学特点,接着简要介绍了传统资源评估模型的分类,最后详细阐述了目前应用于短生命周期种类的资源评估模型与方法,同时,本文对渔业资源评估模型中存在的问题进行了探讨,并对其未来的发展进行了展望。 相似文献
10.
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
11.
Size at age, growth rates, seasonality of spawning, and size at maturity were described for the silver sweep Scorpis lineolatus off the coast of New South Wales, Australia. Estimates of age were made by counting annual zones in sections of otoliths. The ageing technique was validated using young‐of‐the‐year fish, staining fish with tetracy‐cline, and by marginal increment analysis. Silver sweep exhibited extreme longevity with an observed maximum age of 54 years and more than 50% of the fishery being greater than 15 years old. Growth was rapid during the first few years before reaching sexual maturity at 2–3 years and at a length of c. 17 cm fork length, after which growth slowed dramatically. Silver sweep displayed a winter spawning period. The fishery is unusual in that despite heavy fishing pressure and rapidly declining catches the age structure of the catch suggests a population that has been subjected to minimal fishing mortality. It is proposed that the large declines in commercial landings may be the result of serial depletion on local reefs and that current landings are being taken from schools of fish that have" receiveddate="little fishing pressure historically. 相似文献
12.
Monthly fishery survey data of the small yellow croaker Larimichthys polyactis in the southern Yellow Sea from2003 and 2013 were employed to evaluate the variation in the resource distribution and biological characteristics(especially body length and sex ratio) in the population on a decadal scale.The results indicated that the small yellow croaker migrated from the Shawai fishing ground to the Dasha fishing ground in spring and was mainly distributed in the central and western parts of the Dasha fishing ground in April and May.Larimichthys polyactis in the Dasha fishing ground migrated eastward to offshore wintering grounds in autumn and reached the central Dasha fishing ground in October and November.The small yellow croaker entered the western waters of the Shawai fishing ground in winter.A large number of age 0+ fish occurred in the Shawai and Jiangwai fishing grounds in October of 2003 and 2013.The body lengths of the spawning stock and wintering stock in 2013 were larger than those in 2003,and the monthly sex ratios(female to male) were significantly less than 1 in both years.The monthly distribution of this fish in the southern Yellow Sea was consistent with a previous finding that "the stock migrated between the wintering grounds in the west of Jeju Island and the Lüsi spawning grounds" but tended to move more northward,with the spawning grounds extending outward.In the past decade,body length variation experienced a decline after an increase,rather than a steady decrease.The sex ratio in the single-stick stow net showed a tendency to increase over the decade,but was either less than or more than 1 depending on the fishing gear;therefore,further studies should be conducted to determine the sex structure. 相似文献
13.
厦门海域渔业资源评估 总被引：7，自引：0，他引：7
以初级生产力和渔业统计资料为材 ,分别应用Tait沿岸海域生态系能流分析法、营养动态法和Cushing等 3种模式 ,估算厦门沿岸海域的渔业资源自然生产量。同时 ,分别应用Schaefer和Fox两种剩余产量模式估算最大持续产量和最大持续捕捞力量。前 3种模式估算该海域的资源生产量分别为 2 0 1 0 5t,1 8463t和 1 7489t,平均 1 8686t。后两种模式估算最大持续产量平均值分别为 9639t和 91 0 4t。估算的最大持续捕捞力量 :5种作业综合总功率为 1 5976kW ;以厦门机定置渔船单位功率渔捞效率为标准估算的总功率为 2 7351kW ;以厦门机刺网渔船单位功率渔捞效率为标准估算的总功率为 432 1 3kW。 1 997年实际渔获量和捕捞力量均超过了估算的最大持续产量和最大持续捕捞力量。文中还讨论了捕捞力量的调整问题。 相似文献
14.
黄海是中国大陆和朝鲜半岛之间的陆架浅海,北起鸭绿江口,南迄长江口北,西北部与渤海相通,南部和东海相连。这个海域位于暖温带,既有暖流的进入,又有沿岸流和冷水团终年存在。这样的环境条件,决定了海洋动物区系和渔业资源中以暖温性鱼类(小黄鱼、真鲷、蓝点鲅、青鳞鱼、皱唇鲨、孔鳐等)为主、同时兼有暖水性(鲐鱼、鳓鱼等)和冷温性(太平洋鲱、鳕鱼 相似文献
15.
东、黄海底拖网渔业渔捞努力量修正方法的探讨 总被引：1，自引：0，他引：1
渔捞努力量在渔业资源研究中是一个重要参数。在以往的东、黄海底拖网渔业资源研究中,投网次数常作为渔捞努力量的度量单位。在底拖网渔业中有很多影响渔捞努力量的因素,其中船型大小、实际捕捞时间的长短以及网具改进是主要因素。本文针对这三个因素应用上海市海洋渔业公司的资料,提出了一种修正方法,并对修正后标准渔捞努力量的效果进行了分析探讨。 相似文献
16.
我国海洋渔业地理信息系统发展现状 总被引：1，自引：0，他引：1
详细总结了我国海洋渔业地理信息系统的研究与应用现状,远洋渔业地理信息系统主要应用于金枪鱼、鱿钓业和秋刀鱼的资源分布、渔获量与渔场环境关系、渔情预报、渔场图绘制等方面,近海主要用于分析东海渔业资源分布和漂移特征、渔场环境分布、部分种类渔获量分布与环境关系及渔情预报等方面。除渔业资源与渔场领域外,渔业地理信息系统还被应用到渔船跟踪、捕捞违法行为判别、渔业信息发布和水产品查询,以及渔港建设等领域,国内学者在进行渔业地理信息系统技术应用的同时,还注重了其技术的研究及改进。 相似文献
17.
In the Northeast US fishery managers have attempted to control marine recreational fishing mortality through annual adjustments to the number and/or size of fish that can be kept. These measures, with a few exceptions, have generally failed to prevent recreational fishing mortality rates from exceeding annual target levels. In this study, we show that one of the reasons why keep limits may have failed is that a substantial number of anglers obtain little value from being able to keep self-caught fish. Our findings are based on a telephone survey administered to marine anglers in all of the coastal counties in the Northeast US in 2004/2005. To evaluate the importance of keeping self-caught fish, we provide estimates of the size of the marine angling population in the Northeast US that keeps fish for food or income and also for those that fish primarily for recreation and place little or no value on keeping fish. Demographic characteristics of the two groups of anglers are compared statistically and differences related to consumption of self-caught marine resources and to health warning advisories are discussed. We also estimate the size of the Northeast US angling population that relies on their self-caught marine resources as a cost-saving food source or as a supplement to household income. This information could improve the effectiveness of fisheries regulations and the ability of policy analysts to predict how anglers might be affected by proposed fishery management actions. 相似文献
18.
Maximum sustainable yield (MSY) has been adopted as the primary management goal by several inter-government fishery organisations, and in the United States it forms the cornerstone of federal fishery management policy. MSY became a strategic goal for the management of Europe's fisheries following the resolution of the World Summit on Sustainable Development in 2002 to restore or maintain fish stocks to MSY levels by 2015. Calculation of MSY requires information on the rate at which biomass increases through growth and reproduction and the rate at which it decreases through natural mortality and fishing. Population-selection, which measures the age-specific rates of fishing mortality, is a key component for the calculation of yield as a function of fishing mortality and MSY, yet selection rarely features in either management advice or sensitivity analyses. Effective management of selection can potentially lead to increases in long-term yield, but before taking action managers need to understand what long-term increases are possible. Using a hypothetical stock, equilibrium yield curves were calculated for three scenarios in which the shape of the population-selection curve varied. The results illustrate the potential extent of variation in MSY and the corresponding fishing mortality required to achieve it (FMSY) that may result solely due to changes in population selectivity. They show that relatively subtle changes in selection can produce substantial differences in MSY and FMSY. The results are discussed with specific reference to the development of long-term management targets and the mechanisms by which managers might try to influence population-selection. 相似文献
19.
Qiang Wu Qingpeng Han Yue Jin Tao Yang Zhongyi Li Xiujuan Shan Xianshi Jin 《海洋学报(英文版)》2022,41(12):80-86
With the decline in fish resources worldwide, the ecological dominance and economic importance of crustaceans have obviously increased. Among crustacean species, mantis shrimps are increasingly dominant in many coastal waters of the world. In China, Oratosquilla oratoria is the most widely distributed and productive species of mantis shrimp, and its relative resource density is the highest in the Bohai Sea. In this study, we analysed the long-term and monthly population characteristics of O. oratoria in the Bohai Sea, including its relative resource density, body size and spatial distribution. The results showed that the relative resource density of O. oratoria in the Bohai Sea increased from 3.59 kg/h in 1982 to 14.48 kg/h in 2018, and the percentage of this species that serves as a fishery resource increased from 4.22% in 1982 to 35.27% in 2018, based on the mean relative resource density in May and August. The relative resource density of O. oratoria in the fishing moratorium season from May to August was significantly higher than that in the other months of fishing season, and the relative resource density decreased rapidly after the fishing moratorium ended. The relative resource density of O. oratoria was the highest in summer (August), followed by in autumn (October) and spring (May), and it was the lowest in winter (January). The relative resource density of O. oratoria in the western Bohai Sea was higher than that in the eastern Bohai Sea. The mean body weight of O. oratoria in the Bohai Sea decreased from 21.95 g in 1982 to 14.34 g in 2018, based on the mean body weight in May and August. The body size of O. oratoria in the fishing moratorium season was significantly higher than that in the fishing season, and the body size decreased rapidly after the fishing moratorium ended. Overall, in the context of declining resources of most fishery species, the relative resource density of O. oratoria increased due to its hardiness and adaptability, and its body size decreased under intensive fishing over the past 30 years. The fishing moratorium system had a great influence on the population dynamics of O. oratoria in terms of the relative resource density and body size in the Bohai Sea. 相似文献