福建省内陆捕捞渔具的作业类型及其数量组成分析

本文根据2009年8月至12月福建省捕捞业渔具渔法普查资料,分析整理了福建内陆地区捕捞业渔具渔法现状调查数据.结果表明:福建内陆地区捕捞渔具有刺网类、钓具类、笼壶类、拖网类、张网类、陷阱类、耙刺类、地拉网类、敷网类、掩罩类、抄网类和杂渔具等12个类别、21种作业型式、渔具总数量123204张(个、顶等).按渔具类别划分...     

温州市张网捕捞能力的分析

根据2003年温州市4个地区张网渔业调查数据,运用数据包络法分析其捕捞能力。结果表明,2003年温州市张网平均利用率为89.2%。考虑了协同作用后,把占有率也当作产出,平均利用率提高至95.2%,能力产量达到109453 t。如果要保持现有产量,则可减船71艘。     

Examining changes in participation in recreational fisheries in England and Wales

Abstract Inland fisheries in England and Wales have high economic and social values. Managing participation to maximise fishery performance is key to maintaining this status. The capital value of fishing rights for migratory salmonid fisheries is €165 million. Coarse fisheries contribute €1030 million to the economy. The central tenet to increasing participation in recreational salmonid fisheries is that an increase in stock size will result in more anglers accessing the fishery. This was examined for salmon on the rivers Usk and Lune where exploitation restrictions increased the number of salmon available to anglers. On the River Lune, the number of salmon available post‐intervention increased by 66%. There was no significant increase in catch while the number of anglers decreased by 16.3%. On the River Usk, the closure of the net fishery potentially resulted in an additional ～1200 salmon being available. Following closure, there was no significant change in rod catch or in the number of anglers. Increased participation is dependent less upon stock manipulation for coarse fisheries and more upon facilitating the activity. In recent years, urban fishery development programmes have provided improved access to local fishing opportunity. Also, new anglers have been targeted through campaigns such as Get Hooked on Fishing and the Scout Angler Badge.     

我国综合养鱼生态模式及其发展思路

我国主要的综合养鱼生态模式有渔农综合经营型,渔牧综合经营型,渔、农、牧综合经营,农庄式立体种养生态系统等。然而劳动力素质限制了其综合利用水平的提高,水质污染影响渔业可持续发展,综合养鱼生态系统基础研究滞后及渔业产业化经营程度不高均是亟待解决的问题。并指出了促进综合养鱼生态模式的发展思路。     

北京市水生动物防疫工作现状和发展对策

当前我国渔业正处于从传统渔业向现代渔业转变的关键时期,坚持用科学发展观指导新时期水产养殖业发展,是促进渔业经济增长方式转变,保证水产养殖持续健康发展的前提。应将以人为本的科学发展观、人与自然和谐发展、循环经济、资源节约和环境友好的思想、理念,落实到水产养殖业未来的发展中。     

Decreasing shrimp (Pandalus borealis) sizes off Newfoundland and Labrador – environment or fishing?

During the 1990s, carapace length statistics including minimum size caught (L_min), mean male and female lengths, size at sex transition (L₅₀) and maximum size (L_max) of northern shrimp (Pandalus borealis) decreased in commercial and survey catches off Newfoundland and Labrador. Decreased growth rates caused by decreases in per‐capita food availability due to large population increases, exacerbated by increased metabolic demands from higher water temperatures in the mid‐1990s, appear to be the main cause of the size decrease. Fishing could have had an accelerating effect on environmentally driven decreases in shrimp growth and size by ‘cropping’ the largest shrimp from the population. The greatest decreases in shrimp size occurred in Hudson Strait and the adjacent northern shelf, the area which also has the highest densities and largest shrimp. We hypothesize that the greater size decrease here resulted from decreased primary production from decreased nutrient flux into the euphotic zone, caused by increased atmospheric warming, freshwater runoff and stratification during the warming trend of the 1990s.     

金枪鱼围网渔船的设计特点

在收集大量资料的基础上 ,分别就金枪鱼围网鱼船主要尺度的选择、最佳船型的论证、航速性与稳性以及总布置特征进行了阐述 ,并且提供部分近似公式及有关数据以供设计时应用。最后 ,对金枪鱼围网渔船的鱼舱设置及与保鲜方法的关系作了介绍     

Influence of terminal rig configuration on the anatomical hooking location of line-caught yellowfin bream, Acanthopagrus australis

Abstract  Experiments were carried out to test the dependence of anatomical hooking location on terminal rig configuration, and identify strategies by which hook ingestion can be minimised to reduce post-release mortality of angled yellowfin bream, Acanthopagrus australis (Günther). Eighty-five anglers targeted yellowfin bream using different designs and sizes of circle and J hooks and recorded technical, environmental and biological data for each landed fish. Considerably fewer fish (16.6 and 8.5%, respectively) ingested hooks than those hooked in the mouth (82.1 and 88.6%), and a greater percentage of J hooks were ingested than circle hooks or a J hook modified with a 15-mm horizontal bar. Irrespective of hook type, the rate of ingestion also declined with increasing hook weight and decreasing fish size. In cage experiments, significantly more hooks baited with natural soft baits (e.g. intestines and cephalopods) were ingested than those baited with artificial baits, crustaceans or teleosts, while in the field fewer hooks were ingested using artificial bait (e.g. bread and pellets) than terrestrial animals, teleosts, crustaceans, teleost or terrestrial animal intestines, cephalopods or polychaetes. Similarly, rigs with floats, short traces or a sinker only on the hook, along with angling in environments with at least some current reduced ingestion. Based on this study, anglers targeting yellowfin bream should be encouraged to use circle or modified J hooks and, regardless of the hook design, the largest hook size possible attached to short traces or a sinker only and hard baits.     

微电脑在二片式对拖网设计上的应用及捕捞效果分析

本文分析了二片式对拖网设计软件设计的基本原理及渔获效果的对比。结果表明,本软件设计先进、科学,具有良好的适用性、精确性、高度灵活性和快速简便性等优点;利用本软件设计的网具,具有良好的渔获效果。     

遗传算法及其在渔饲料配方中的应用

首先阐述了参数编码、初始群体、适应度函数、遗传操作以及算法控制参数等遗传算法基本原理,然后着重介绍其在渔饲料配方中的应用,在该应用中采用了实数编码、基于线性排名的选择、算术杂交和非一致变异等遗传算法方法。结果表明,在渔饲料配方优化中应用遗传算法要优于目前饲料配方软件中大多采用的常规应用数学的优化方法。主要体现在单位产量饲料配方中的成本价格前者要低于后者。由于遗传算法能够解决因子较多,非线性程度高的问题,从而得出的饲料配方能更好的符合相关鱼种的营养含量标准。