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首页> 外文期刊>ICES Journal of Marine Science >Current status and temporal trends in stocks of European eel in England and Wales
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Current status and temporal trends in stocks of European eel in England and Wales

机译：英格兰和威尔士欧洲鳗鱼的现状和时间趋势

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摘要

An extensive 4-year programme of catchment surveys, data collection, and model development for eels was undertaken to establish the status of the stocks in England and Wales, so that appropriate management action can be taken. Nine test catchments representing different geographical areas and catchment types were studied, covering 14 rivers, two estuaries, and a fresh-water lagoon. Data were collected via electric fishing, fykenetting, fixed eel racks, and elver traps. In all, 13 500 eels were caught, weighed, and measured, and the sex and age of a subsample of 1400 determined. Despite declining recruitment, eel stocks in some, perhaps many, west coast rivers are probably still at or near to carrying capacity, with male-dominated populations. In other rivers, particularly those towards the southeast of England, current and historical data indicate declining female-dominated stocks. For rivers where recruitment is not limiting, there appears to be a direct relationship between the standing stock of eels and the mean nitrate level. This relationship potentially facilitates the application of a biomass-based biological reference point for eels for application to individual catchments. The data also suggest that it may be possible to develop reference points based on mean eel length or sex ratio.
机译：为了确定鳗鱼在英格兰和威尔士的种群状况，开展了一项为期四年的广泛的流域调查，数据收集和鳗鱼模型开发计划，以便采取适当的管理措施。研究了代表不同地理区域和集水区类型的9个测试集水区，覆盖了14条河流，两个河口和一个淡水泻湖。数据通过电钓鱼，鱼钩，固定的鳗鱼架和诱捕器收集。总共捕获，称重和测量了13500条鳗鱼，并确定了1400个子样本的性别和年龄。尽管招募人数减少，但在西海岸的一些甚至许多河流中，鳗鱼种群仍可能处于或接近载畜量，其人口以男性为主。在其他河流，特别是英格兰东南部的河流中，当前和历史数据表明，以女性为主的种群正在减少。对于没有限制补充的河流，鳗鱼的存量与平均硝酸盐水平之间似乎存在直接关系。这种关系潜在地促进了基于鳗鱼的基于生物质的生物参考点的应用，以应用于各个流域。数据还表明，有可能根据平均鳗鱼长度或性别比得出参考点。

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