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首页> 外文期刊>ICES Journal of Marine Science >Cod in fjords and coastal waters of North Norway: distribution and variation in length and maturity at age
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Cod in fjords and coastal waters of North Norway: distribution and variation in length and maturity at age

机译：挪威北部峡湾和沿海水域的鳕鱼：成年时长和成熟度的分布和变化

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摘要

The distribution of cod along the Norwegian coast and in fjords from 62°N north to the Russian border was examined using data from annual trawl surveys carried out between 1995 and 2001. Based on differences in growth zones of the otoliths, cod are traditionally classified into two types: Northeast Arctic cod and coastal cod. Both types were found throughout the area investigated. The catch rate of both increased northwards and from offshore to inshore. In a statistical model of length at age, abiotic factors such as area and year of capture explained more of the variance than biotic factors such as sex, stage of maturity, and type of cod. Length at age increased in a southward direction and was higher for cod captured offshore than for those captured inshore. In a statistical model of the proportion mature at age, area, type, and year of capture explained more of the variance than sex and depth of capture. On average, coastal cod attained 50% maturity (M_(50)) more than a year younger than Northeast Arctic cod. Although there were relatively large differences in age at maturity between neighbouring areas, age at maturity was lowest in the south and inshore, and in general, lower inshore than offshore. As genetic analysis clearly indicates that cod in the study area consist of at least two genetically separated stocks, it is likely that the differences found here in age at M_(50) might have a genetic component.
机译：使用1995年至2001年之间进行的年度拖网调查数据，研究了鳕鱼在挪威海岸和北至北纬62°到俄罗斯边界的峡湾中的分布。根据耳石生长区域的差异，传统上将其划分为两种类型：东北鳕鱼和沿海鳕鱼。在整个调查区域都发现了这两种类型。北方和从近海到近海的捕捞率均增加。在年龄的统计模型中，非生物因素（例如捕获的面积和年份）比生物因素（例如性别，成熟阶段和鳕鱼类型）解释的差异更大。成年后的长度向南增加，在近海捕捞的鳕鱼比在近海捕捞的鳕鱼长。在年龄，区域，类型和捕获年份成熟的比例的统计模型中，解释的差异远大于性别和捕获深度。平均而言，沿海鳕鱼的成熟度比东北北极鳕鱼年轻50％（M_（50））。尽管相邻地区之间的成熟年龄差异较大，但南部和近岸的成熟年龄最低，通常，近岸低于近海。遗传分析清楚地表明，研究区域内的鳕鱼至少由两种遗传分离的种群组成，因此这里的M_（50）年龄差异可能具有遗传成分。

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