Effects of Trawl Selectivity and Genetic Parameters on Fish Body Length Under Long-Term Trawling

来源 :Journal of Ocean University of China | 被引量 : 0次 | 上传用户:xucaijuan302
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
Long-term fishing pressure affects the biological characteristics of exploited fish stocks. The biological characteristics of hairtail(Trichiurus lepturus) in the East China Sea are unable to recover because of long-term trawling. Fishing induces evolutionary effects on the fish’s biological characteristics. Evidence of these changes includes small size at age, a shift to earlier age structure, and early maturation. Natural and artificial selection usually affect the fish’s life history. Selection can induce different chances of reproduction, and individual fish can give a different genetic contribution to the next generation. In this study, analysis of time-dependent probability of significance and test of sensitivity were used to explore the effects of fish exploitation rate, mesh size, and heritability with long-term trawling. Results showed that fishing parameters were important drivers to exploited fish population. However, genetic traits altered by fishing were slow, and the changes in biological characteristics were weaker than those caused by fishing selection. Exploitation rate and mesh size exhibited similar evolutionary trend tendency under long-term fishing. The time-dependent probability of significance trend showed a gradual growth and tended to be stable. Therefore, the direction of fishing-induced evolution and successful management of fish species require considerable attention to contribute to sustainable fisheries in China. Long-term fishing pressure affects the biological characteristics of exploited fish stocks. The biological characteristics of hairtail (Trichiurus lepturus) in the East China Sea are unable to recover because of long-term trawling. Evidence of evolutionary effects on the fish’s biological characteristics. Evidence of these changes includes small size at age, a shift to earlier age structure, and early maturation. Natural and artificial selection generally affect the fish’s life history. Selection can induce different chances of reproduction, and individual fish can give a different genetic contribution to the next generation. In this study, analysis of time-dependent probability of significance and test of sensitivity were used to explore the effects of fish exploitation rate, mesh size, and heritability with long-term trawling. Results showed that fishing parameters were important drivers to exploited fish population. However, genetic traits altered by fishing were slow, and the chan ges in biological characteristics were weaker than those caused by fishing selection. Exploitation rate and mesh size successfully similar evolutionary trend tendency under long-term fishing. Therefore, the time-dependent probability of significance trend showed one gradual growth and tended to be stable. direction of fishing-induced evolution and successful management of fish species require displayed to contribute to sustainable fisheries in China.
其他文献
期刊
对于幼儿而言,尤其是五到六岁的幼儿,他们的本性就是爱玩,喜欢游戏,游戏是他们每天的重心,那么要想让幼儿的各方面能力得到发展,就需要将游戏和幼儿教学有效地进行结合.阅读
为实现大运河动态监测和管理,根据空间信息科学和历史文化遗产保护理论,探讨基于空间信息技术的京杭大运河历史文化环境保护方法流程和技术路线,研制了大运河历史文化环境保护支持系统,并实际应用于南水北调东线一期工程的大运河历史文化环境保护研究工作,产生了一系列专题研究成果。结果表明,空间信息技术可以为历史文化环境保护提供强有力的技术支持和可靠保障,可以为缓解大运河历史文化环境保护与南水北调工程建设的矛盾、
【摘要】本文针对高中学生解读史料的现状,制定了史料解析原则,通过培养学生史料信息提取能力、理解能力、评价能力,有效提高了学生的史料解析能力。  【关键词】高中生 史料解析能力 培养  【基金项目】本文系河南省基础教育教学研究项目《高中文科生史料解析能力的培养研究》(河南省教育厅教基研〔2014〕795号,立项编号:JCJYB141125012)研究成果。  【中图分类号】G633.51【文献标识码
导入作为英语课堂教学的首要环节,在初中英语课堂中发挥着举足轻重的作用.一个好的英语课堂导入可以在短时间内集中学生注意力,激发学生兴趣,调动学生主动性与积极性,从而提
2014年,对于我们后塍小学来说是比较特殊的一年。我带了三年的班级,突然面临学校的合并分拆,使原来八个班级重新组合,尤其是还有两个班级是从民工子弟学校调来的,全部是新市民学生
摘 要:在新《纲要》中明确指出:“幼儿园的教育活动,就是教师以多种形式有目的、有计划地引导幼儿生动活泼、主动活动的教育过程”。而要想引导幼儿积极地进行活动,游戏是最好的方式。对于幼儿来说,他们喜欢游戏,特别是户外游戏。基于此,为了促使农村幼儿园更好地进行户外游戏,以及对其进行观察,在接下来的文章中,将以农村幼儿园进行户外游戏的重要性为切入点,重点对其进行有效户外游戏的措施展开详细分析。  关键词:
新学期开始了,我发现小俊这个孩子像换了个人:上课没几分钟就坐不住了,不是眼睛盯着窗外,就是钻在课桌下面做小动作,实在无聊了,就去找周围的同学海聊……提不起一点儿学习的
当车企遭遇互联网的冲击,当主流芯片厂商纷纷进军车载系统领域,汽车产业传统的研发、生产模式也必将出现重大变革。之前福特虚拟现实设计实验室,工程师只需要头戴3D成像设备,在专
【摘要】多媒体巧妙运用于语文课堂教学,可以充分激发学生的学习兴趣,化抽象为形象,帮助学生突破课文难点的学习,还能拓展学习空间,培养学生的语文综合能力。作为新科技时代的教师,我们应当把多媒体巧妙运用于教学中,优化语文课堂教学效果。  【关键词】多媒体 语文 教学 效果  【中图分类号】G623.2【文献标识码】A 【文章编号】2095-3089(2016)03-0050-01  多媒体教学,作为学校