Fishery stock assessment of Kiddi shrimp (Parapenaeopsis stylifera) in the Northern Arabian Sea Coas

来源 :Chinese Journal of Oceanology and Limnology | 被引量 : 0次 | 上传用户:jiushiaijiujiu
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
Pakistani marine waters are under an open access regime.Due to poor management and policy implications,blind fishing is continued which may result in ecological as well as economic losses.Thus,it is of utmost importance to estimate fishery resources before harvesting.In this study,catch and effort data,1996-2009,of Kiddi shrimp Parapenaeopsis stylifera fishery from Pakistani marine waters was analyzed by using specialized fishery software in order to know fishery stock status of this commercially important shrimp.Maximum,minimum and average capture production of P.stylifera was observed as 15 912 metric tons(mt)(1997),9 438 mt(2009) and 11 667 mt/a.Two stock assessment tools viz.CEDA(catch and effort data analysis) and ASPIC(a stock production model incorporating covariates) were used to compute MSY(maximum sustainable yield) of this organism.In CEDA,three surplus production models,Fox,Schaefer and Pella-Tomlinson,along with three error assumptions,log,log normal and gamma,were used.For initial proportion(IP) 0.8,the Fox model computed MSY as 6 858 mt(CV=0.204,R~2=0.709) and 7 384 mt(CV=0.149,R~2=0.72) for log and log normal error assumption respectively.Here,gamma error produced minimization failure.Estimated MSY by using Schaefer and Pella-Tomlinson models remained the same for log,log normal and gamma error assumptions i.e.7 083 mt,8 209 mt and 7 242 mt correspondingly.The Schafer results showed highest goodness of fit R~2(0.712) values.ASPIC computed MSY,CV,R~2,F_(MSY)and B_(MSY) parameters for the Fox model as 7 219 mt,0.142,0.872,0.111 and 65 280,while for the Logistic model the computed values remained 7 720 mt,0.148,0.868,0.107 and 72 110 correspondingly.Results obtained have shown that P.stylifera has been overexploited.Immediate steps are needed to conserve this fishery resource for the future and research on other species of commercial importance is urgently needed. Pakistani marine waters are under an open access regime. Due to poor management and policy implications, blind fishing is continued which may result in ecological as well as economic losses.Thus, it is of utmost importance to estimate fishery resources before harvesting. In this study , catch and effort data, 1996-2009, of Kiddi shrimp Parapenaeopsis stylifera fishery from Pakistani marine waters was analyzed by using specialized fishery software in order to know fishery stock status of this very important shrimp. Minimum, minimum and average capture production of P. CEFA (catch and effort data analysis) and ASPIC (a stock production model in Chinese) were tested as 15 912 metric tons (mt) (1997), 9 438 mt (2009) and 11 667 mt / a .wo stock assessment tools viz. covariates) were used to compute MSY (maximum sustainable yield) of this organism. CEDA, three surplus production models, Fox, Schaefer and Pella-Tomlinson, along with three error assumptions, log, log normal and gamma, were used. Fo r initial proportion (IP) 0.8, the Fox model computed MSY as 6 858 mt (CV = 0.204, R ~ 2 = 0.709) and 7 384 mt (CV = 0.149, R ~ 2 = 0.72) for log and log normal error assumption respectively. Here, gamma error produced minimization failure. Estimated MSY by using Schaefer and Pella-Tomlinson models remained the same for log, log normal and gamma error assumptions ie7 083 mt, 8 209 mt and 7 242 mt correspondingly. The Schafer results showed showed The highest goodness of fit R ~ 2 (0.712) values.ASPIC computed MSY, CV, R ~ 2, F_ (MSY) and B_ (MSY) parameters for the Fox model as 7 219 mt, 0.142, 0.872, 0.111 and 65 280, while for the Logistic model the computed values ​​remained 7 720 mt, 0.148, 0.868, 0.107 and 72 110 correspondingly. Results obtained have been shown that P. stylifera has been overexploited. Immediate steps are needed to conserve this fishery resource for the future and research on other species of commercial importance is urgently needed.
其他文献
Calanus sinicus,the dominant copepod in the Yellow Sea,develops a large oil sac in late spring to prepare for over-summering in the Yellow Sea Cold Water Mass(Y
名著中的动作描写有多种表达功能。一、凸现性格特征于是他噗嗤一笑,磕了磕吸尽了的烟灰,……慢吞吞、笑嘻嘻地吐了一口痰,把嘴一抹说道:“………你怎么知道我是共军呢?嗯?!
《全日制义务教育普通高级中学英语课程标准》将突出学生的参与意识和实践活动,提高学生运用英语的能力作为英语教学的重要内容。在现代英语教学中,教师是教学情境的设计者,是引导建构的促进者,是学生遇到困难时的帮助者,是学生能力和良好个性品质的培养者,所以教师应注重培养学生的积极性、主动性、独立性和创造性。基于以上观点,在首师大虚拟学习社区智能教学支撑平台的支持下,我讲授了这一节课。我提前在网上公布本节课的
李比希是19世纪德国一位著名的化学大师,对无机化学、有机化学、生物化学都曾有过重大贡献,被西欧许多国家评为科学院院士或名誉院士。就是这样一位名人,竟有一件事让他抱憾
A three-dimensional numerical model was established to simulate the hydrodynamics within an octagonal tank of a recirculating aquaculture system.The realizable
本期谈论的话题是“考试后如何反思与总结”,怎样对待每次考试,如何从每次考试中总结经验教训,这是大家关注的问题.虽然老师常强调学习过程比考试结果更为重要,但考试后的总
按照接受美学的理论,作为人类审美活动的一种重要载体,文学及文学作品通过情感投射和移情的作用,让读者与作者在文本中相遇,实现一种理想状态的“共鸣”。在文学作品创作和接
一、中学“复数”教材在演变 现代科学技术的迅速进展,迫使人们不断地探索改革中学数学教材,以满足科技、生产和进一步学习的需要。中学复数教材的演变便是一例。 回顾我国
我们生活在一个光明的世界里,早晨,太阳从东方冉冉升起,朝霞映红了海面;中午烈日当空,光芒万丈;傍晚,几度夕阳红;还有光怪陆离的霓红灯在装点着繁华都市的夜空,使黑夜变得绚
综观近年各类数学竞赛试卷,有关完全平方式的题目屡见不鲜.常用的公式有: ①完全平方公式:a2±2ab+b2=(a±b)2. ②三项式完全平方公式:a2+b2+c2+2ab+2bc+2ca=(a+b+c)2. 由此