Vertical migrations of fish larvae: Eulerian and Lagrangian observations in the Eastern English Channel
Vertical migrations of fish larvae: Eulerian and Lagrangian observations in the Eastern English Channel
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鱼类幼虫的垂直迁移：东英吉利海峡的欧拉和拉格朗日观测
DOI：
10.1093/plankt/22.10.1813
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发表时间：
2000
影响因子：
2.1
通讯作者：
L. Lago
中科院分区：
文献类型：
--
作者：
A. Grioche;X. Harlay;P. Koubbi;L. Lago
东英吉利海峡以其强大的水动力而闻名。潮汐流和余流受到西南主导风的加强，并将沃茨从英吉利海峡漂流到北海。先前的空间研究表明，幼虫的平流可能不同，从一个物种到另一个。比目鱼（Pleuronectes flesus）的幼虫在近海被发现，向北漂流，直到鳍形成;然后在海岸附近被发现。然而，唯一的（Solea solea）幼虫留在沿海沃茨在其发展。幼虫的空间分布的差异被认为是有关的垂直迁移和平流之间的相互作用，由替代潮流，导致选择性的潮流运输。为了描述这些幼虫的垂直分布，使用了两种策略。首先，在同一地理位置每隔1.5 h采集样本，持续41 h，进行欧拉研究。鱼类浮游生物收集在水体中使用邦戈网和一个超底栖多网雪橇，在四层以上的海床，0.1和1.4米之间。其次，为了使水的运动被忽略，拉格朗日研究进行了使用邦戈网每3小时，以下漂流浮标3天。结果表明，即使在最年轻的阶段，唯一的幼虫能够进行潮汐和昼夜垂直迁移。我们假设，它们可能会限制其平流到北海，因为它们在退潮和夜间向上迁移，这可能使它们能够留在同一地区处理电流。比目鱼仔鱼开始垂直迁移的时期为脊索屈曲期，此时比目鱼仔鱼的北漂行为结束。幼虫到达水柱的底部，特别是在退潮时，它们集中在底部上方的前40厘米处。这种行为有利于它们在流动过程中的平流，从而有效和快速地向海岸输送。
The Eastern English Channel is known for its strong hydrodynamics. Tidal and residual currents are reinforced by the south-western dominant wind and drift waters from the English Channel to the North Sea. Previous spatial studies have shown that the advection of larvae could differ from one species to another. Flounder (Pleuronectes flesus) larvae were found offshore, drifting to the north until the fins were formed; then they were found near the coast. However, sole (Solea solea) larvae remained in coastal waters during their development. The difference in larval spatial distribution is assumed to be related to the interaction between vertical migration and advection by alternative tidal currents, leading to a selective tidal stream transport. To describe the vertical distribution of these larvae, two strategies were used. First, a Eulerian study was carried out with samples taken at the same geographical location every 1.5 h for 41 h. Ichthyoplankton were collected in the water mass using a Bongo net and with a suprabenthic multi-net sledge, at four layers above the sea bed, between 0.1 and 1.4 m. Secondly, to enable water movement to be disregarded, a Lagrangian study was carried out by using a Bongo net every 3 h, following a drifting buoy for 3 days. The results show that even during the youngest stages, sole larvae are able to perform tidal and diel vertical migration. We assume that they may limit their advection to the North Sea because of their upward migration during ebb and at night, which may enable them to remain in the same area dealing with the currents. Flounder larvae begin their vertical migration at the stage of notochord flexion, which ends their drift to the north. The larvae reach the bottom of the water column, particularly during ebb when they are concentrated in the first 40 cm above the bottom. This behaviour favours their advection during flow, leading to efficient and fast transport towards the coast.