Tuna food habits related to the micronekton distribution in French Polynesia
Tuna food habits related to the micronekton distribution in French Polynesia
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DOI：
10.1007/s00227-001-0776-3
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发表时间：
2002-05-01
期刊：
影响因子：
2.4
通讯作者：
Josse, E
中科院分区：
文献类型：
--
作者：
Bertrand, A;Bard, FX;Josse, E
胃内容物分析通常用于研究鱼类摄食行为和营养状况。然而，这些数据的解释取决于鱼觅食行为，为一个给定的环境，以及如何代表胃内容物的猎物分布。在法属波利尼西亚进行的一项研究方案范围内对金枪鱼的摄食行为进行了研究。金枪鱼猎物分布的特点是使用声学测量和远洋拖网，此后，这种分布进行了比较，使用仪器延绳钓捕获金枪鱼的胃内容物。声学、中上层拖网和胃内容物分析提供了描述中上层营养生境和更好地了解金枪鱼-猎物关系的补充要素。热带海洋环境中金枪鱼食物供应减少的传统概念似乎是相对的。金枪鱼能够在白天潜水足够的时间来利用迁徙的微浮游生物物种，从而获得常规的食物来源。大眼金枪鱼（Thunnus obesus）尤其如此，它们具有实现这一目的的生理生态能力。长鳍金枪鱼（T. alalunga），其潜水深度超过400米，仍然不太清楚，因为对它们的垂直行为知之甚少。黄鳍金枪鱼（T.分布在较浅的沃茨的黄鳍金枪鱼（黄鳍金枪鱼）可以更好地利用从珊瑚礁输出的幼鱼和甲壳类动物的生物量。对被动渔具延绳钓金枪鱼的胃充满度分析表明，金枪鱼的胃一般处于空的状态。这一结果表明，大多数金枪鱼觅食的大型猎物聚集在研究领域的迅速饱和和逃脱延绳钓捕获和采样。其结果是，根据延绳钓对金枪鱼摄食行为的研究可能有偏差，特别是当出现大规模的猎物聚集时，如在趋同区。另一个潜在的后果是延绳钓金枪鱼捕获率可能因猎物丰富程度而异。延绳钓金枪鱼捕获率有时可能反映的是猎物的相对丰度，而不是金枪鱼的相对丰度。本文的电子补充材料可通过位于http://dx.doi.org/10.1007/s00227-001-0776-3的Springer LINK服务器获得。
Stomach content analyses are commonly used to study both fish feeding behaviour and trophic conditions. However, the interpretation of such data depends on fish foraging behaviour for a given environment and how representative the stomach contents are to the prey distribution. Tuna feeding behaviour was studied within the context of a research programme conducted in French Polynesia. Tuna prey distribution was characterised using acoustic measurements and pelagic trawls; thereafter, this distribution was compared with the stomach contents of tuna caught using an instrumented longline. Acoustic, pelagic trawling and stomach content analyses give complementary elements to describe the pelagic trophic habitat and to better understand tuna-prey relationships. The classic concept of a reduced food availability for tunas in the tropical pelagic environment seems relative. Tunas able to dive enough during daytime to exploit the migrant micronektonic species secure a source of regular food. This is particularly true of bigeye tuna (Thunnus obesus), which have ecophysiological capacities for this purpose. The behaviour of albacore tuna (T. alalunga), which dive >400 m in depth, remains less clear, as little is known about their vertical behaviour. Lastly, yellowfin tuna (T. albacares), which are distributed in more superficial waters, can better exploit the biomass of juvenile fish and crustaceans exported from the reefs. Analysis of the stomach fullness of tuna caught by longline, a passive gear, generally showed an empty state. This result suggests that most tuna foraging on large prey aggregations present in the study area are quickly satiated and escape longline capture and sampling. A consequence is that studies of tuna feeding behaviour based on longlining may be biased, particularly when large aggregations of prey are present such as in convergence zones. Another potential consequence is that longline tuna catch rates could differ according to prey richness. Longline tuna catch rates may sometimes reflect the relative abundance of prey rather than relative tuna abundance. Electronic supplementary material to this paper can be obtained by using the Springer LINK server located at http://dx.doi.org/10.1007/s00227-001-0776-3.