拉格朗日插值法在渔业资源评估上的应用

应用拉格朗日插值法拟合鱼类体长与体重之间的函数关系 ,使用计算机VB语言进行编写程序 ,与常用的线性回归法、Ricker法进行比较 ,得出体长与体重的关系式为Pn(x) =∑nk=0yklk(x)=∑nk=0(∏nj=0j≠kx-xjxk-xj)yk 。     

A taxonomical and ecological survey of rotiffer communities in Krottensee (Austria)

The composition and distribution of benthic, periphytic and planktonic rotifers in different habitats in Krottensee were investigated. Sixty-five rotifer taxa were identified, their relative abundance estimated. Classification of the data set by cluster analysis allowed the recognition of distinct habitat groups confined to acid bog ponds, macrophytes, sediments and open water. Five groups of rotifer taxa were identified on the basis of their habitat preferences and the occurrence of the taxa. Highest diversities were found on macrophytes and in acid bog ponds.     

中国辽宁-浙江沿海地区川蔓草分布现状、生态特征及其主要威胁

川蔓草(Ruppia)是一种广泛分布在咸水、半咸水生境中的广义海草, 其形成的川蔓草床具有重要的生态学价值。然而, 对于其在中国境内的分布情况尚缺乏大范围的调查。基于此, 本研究于2016—2019年对中国辽宁-浙江沿海区域的川蔓草分布情况进行了初步调查, 探究了调查区域内川蔓草的生境分布类型, 及生态特征, 分析了川蔓草床的主要威胁, 并提出了对川蔓草床科学管理的建议。结果表明: 川蔓草在中国浙江省、江苏省、山东省、天津市、河北省、辽宁省均有分布; 分布面积超过2 100 ha; 该区域内分布的川蔓草物种均为中国川蔓草, 主要分布生境包括咸水养殖池塘、咸水沟渠(池塘)、盐场、瀉湖(湖泊)、潮间带(围堰)5类; 人类活动影响(人工清捞、施药、河道工程等)与极端气候事件(极端干旱事件)都会导致川蔓草床退化, 但大部分川蔓草床可以依靠沉积物中的种子库在环境适宜时进行种群恢复; 不同生境中的川蔓草种群特征差异较大, 因此, 对不同生境中的川蔓草应制定差异性管理措施。     

Spatial patterns and environmental risks of ringnet fishing along the Kenyan coast

Ringnet fishing began in the early 20th century and is practised worldwide, mainly to target nearshore pelagic species. The method was introduced to Kenya’s coastal waters by migrant fishers from Tanzania. However, the impacts of this fishing gear remain poorly assessed. We assessed the spatial distribution of ringnet fishing effort and its possible effects on ecosystem components, such as coral reefs, marine megafauna and marine protected areas, on the south coast of Kenya. We tracked 89 ringnet fishing trips made from December 2015 to January 2016 and used spatial multicriteria analysis to determine hotspots of possible environmental risks. The results showed that habitat type and bathymetric profile influenced the spatial distribution of ringnet fishing effort. Mixed seagrass and coral habitats had the highest concentration of the effort. Most of the habitats in the study area were moderately exposed to the impacts of the ringnet fishery. The study identifies high-risk areas that require spatial measures to minimise possible environmental risks of the gear both to habitats and to endangered sea turtles.     

A summary of the geology and oil habitat of the Eastern Flank Hydrocarbon Province of South Oman

The Eastern Flank Hydrocarbon Province borders the southeastern edge of the South Oman Salt Basin in the southern part of Oman. An intensive exploration programme by PDO over the past seven years has led to the discovery of almost 2 × 10⁹ m³ of oil with current production of some 15000 m³/d from six fields.In stark contrast to other oil habitats of the Arabian Peninsula, the main play involves rock units and geological events ranging in age from Late Precambrian to Quaternary Times, while trap development and charging are closely related to syn-tectonic salt dissolution.The principal reservoirs and seals are poorly consolidated, Palaeozoic clastics which drape, due to salt dissolution, over residual ‘cores’ principally composed of either Lower Palaeozoic sandstones (Haima Group), or Late Proterozoic carbonates (Huqf Group), or some combination of these. Oils have been geochemically correlated with algal source rocks of the Huqf Eastern Flank. Structures are considered to have been ‘charged’ from Late Mesozoic times onwards in conjunction with progressive subsurface salt removal and the onset of maturation of local source rocks. The effectiveness of ‘charging’ along the retreating salt edge is indicated by the small percentage of dry wells.Major oil zones are found in both anticlinal and truncation traps which are commonly developed around sandstone (Haima Group) cores. Oils show a wide range of characteristics but are typically heavy, early expulsion crudes, high sulphur with little associated gas. Bacterial transformation is not uncommon.Producing reservoirs mainly occur at relatively shallow depths (600–1200 m). Primary recovery factors of around 7% reflect the high density and viscosity of the Eastern Flank crudes and have initiated interest in Enhanced Oil Recovery (EOR) techniques. Two such pilot projects, involving steam and polymer flooding, are due to commence in 1984 and, if successful, will substantially increase the reserve base of these fields.     

几种养殖鲍同工酶生化遗传的比较研究

运用聚丙烯酰胺凝胶电泳对我国主要养殖鲍(皱纹盘鲍、盘鲍及九孔鲍)12种同工酶(LDH、ME、MDH、GPI、PGM、IDH、IDDH、SOD、EST、ODH、ADH、AAT)26个基因座位进行了分析．结果表明：EST、PGM可以作为区分三种(亚种)鲍的生化遗传标记；在所分析的位点中，未发现多态现象，表明三种养殖鲍杂合子缺失严重，其主要原因可能在于哑基因、近交与自然选择。     

人造海洋涌升流和海洋渔场

针对渔业资源日趋减少和鱼产品需求不断增加的矛盾，探讨了建造海底山脉、人工制造海洋涌升流、从而人工制造优良海洋渔场的可行性，分析了我国建造海底山脉的水深、海底和海流条件。介绍了建造海底山脉的建筑方法和国际上建造海底山脉的最新动态。论述了我国在200n mile以内建造海底山脉的有利条件。     

南海北部主要经济鱼类体长与体重关系

文中根据1997～1999年和2001～2002年期间在南海北部底拖网调查的43种共33 389尾鱼的体长（叉长、肛长）和体重数据,应用统计分析方法对各鱼种体长与体重关系进行分析.结果表明,43种鱼分别隶属于4目16科25属,相关系数R^2的范围为0.764～0.993,相关系数R^2值相对较高,其中58%的R^2值超过0.95.幂指数b值范围为2.50～3.44,平均2.90.盒须图分析表明,50%的b值在2.79～3.01范围.经初步分析,43种主要经济鱼类中,有16种为等速生长、22种负的异速生长和5种正的异速生长.