Fluctuations in European eel (Anguilla anguilla) recruitment resulting from environmental changes in the Sargasso Sea
Fluctuations in European eel (Anguilla anguilla) recruitment resulting from environmental changes in the Sargasso Sea
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DOI：
10.1111/j.1365-2419.2007.00453.x
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发表时间：
2008-01-01
影响因子：
2.6
通讯作者：
Rivot, Etienne
中科院分区：
文献类型：
--
作者：
Bonhommeau, Sylvain;Chassot, Emmanuel;Rivot, Etienne
欧洲鳗鱼数量的减少现在已被广泛观察到，涉及大量因素，如过度捕捞、污染、栖息地丧失、水坝建设、河流阻塞、寄生虫和环境变化。在本研究中，我们分析了马尾藻海和大西洋环流的环境条件对欧洲玻璃鳗鱼招募成功的影响。在最近11年的时间里，我们发现了一个很强的正相关性之间的原始指数的玻璃鳗鱼招聘和鳗鱼产卵区的初级生产力（PP）。此外，PP与温度呈负相关，在马尾藻海。因此，我们使用海水温度作为海洋生产的逆代理。在过去四十年中，人们发现在补充量和海水温度的长期波动之间存在着密切的负相关关系。这些发现得到了加强，检测到的制度转变之前，在玻璃鳗鱼招聘在20世纪80年代初开始下降的海水温度。相比之下，测量海洋环流，即纬度和强度的墨西哥湾流的综合指数的变化，似乎并不能解释玻璃鳗鱼招聘的变化。我们的研究结果支持了一个强大的自下而上的控制leptocephali的生存和生长的PP在马尾藻海的短期和长期的时间尺度上的假设。我们认为，自20世纪80年代初以来，在鳗鱼产卵区的海洋变暖已经修改了海洋生产，并最终影响了欧洲鳗鱼在生命早期阶段的存活率。
European eel decline is now widely observed and involves a large number of factors such as overfishing, pollution, habitat loss, dam construction, river obstruction, parasitism and environmental changes. In the present study, we analyzed the influence of environmental conditions in the Sargasso Sea and Atlantic ocean circulation on European glass eel recruitment success. Over a recent 11-yr period, we showed a strong positive correlation between an original index of glass eel recruitment and primary production (PP) in eel spawning area. Moreover, PP was negatively correlated with temperature in the Sargasso Sea. Therefore, we used sea temperature as an inverse proxy of marine production. A close negative relationship has been found over the last four decades between long-term fluctuations in recruitment and in sea temperature. These findings were reinforced by the detection of a regime shift in sea temperature that preceded the start of the decline in glass eel recruitment in the early 1980s. By contrast, variations in integrative indices measuring ocean circulation, i.e. latitude and strength of the Gulf Stream, did not seem to explain variations in glass eel recruitment. Our results support the hypothesis of a strong bottom-up control of leptocephali survival and growth by PP in the Sargasso Sea on short and long time scales. We argue that sea warming in the eel spawning area since the early 1980s has modified marine production and eventually affected the survival rate of European eels at early life stages.