Modelling of unexploited and exploited populations of eels, Anguilla anguilla (L.), in the Thames Estuary
Modelling of unexploited and exploited populations of eels, Anguilla anguilla (L.), in the Thames Estuary
复制标题
泰晤士河口未开发和已开发的鳗鱼种群模型，Anguilla anguilla (L.)
DOI：
10.1111/j.1095-8649.1990.tb03600.x
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发表时间：
1990
影响因子：
2
通讯作者：
B. Knights
中科院分区：
文献类型：
--
作者：
I. Naismith;B. Knights
在一年中的不同时间，在泰晤士河口的不同区域用网捕鳗鱼，并对鳗鱼的性别、年龄和胃内容物进行检查。计算了鳗鱼每3厘米长30厘米的瞬时死亡系数(Z)，并用其构建了一个分区模型，以评估自然死亡和捕捞死亡以及迁徙对雄性和雌性不同生命阶段的影响。增长率良好，渔业死亡率影响低，并被移民/移民(可能还有当地移民)的影响所掩盖。依赖密度的死亡率似乎影响不大。文中还讨论了雄性主宰淡水水域，雌性主宰盐碱地，以及食物可获得性和密度的可能影响。结论是，该种群并未被过度开发，但鳗鱼的招募相对较低。讨论了增加捕捞的方法，以及增加雌性鲸鱼产量的方法，以增加对泰晤士河和其他欧洲河流的麋鹿补充。
Eels were fyke-netted in different zones of the Thames Estuary at various times of year and subsamples sexed, aged and stomachcontentsexamined. Instantaneous mortality coefficients (Z) were calculated for each 3 cm length class for eels > 30 cm and used to construct a compartmental model to assess effects of natural and fishing mortality and migration on different life stages of males and females. Growth rates were good and fishing mortality effects low and masked by effects of emigration/immigration (and, possibly, local migrations). Density-dependent mortality appeared to be having minor effects. Males dominate freshwater sites, females the more saline zone and possible implications of food availability and density are discussed. It is concluded the stock is not being over-exploited but that elver recruitment is relatively low. Means of increasing exploitation are discussed, as are ways of increasing production of females to enhance elver recruitment to the Thames and other European rivers.