Plasticity in vertical behaviour of migrating juvenile southern bluefin tuna (Thunnus maccoyii) in relation to oceanography of the south Indian Ocean
Plasticity in vertical behaviour of migrating juvenile southern bluefin tuna (Thunnus maccoyii) in relation to oceanography of the south Indian Ocean
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DOI：
10.1111/j.1365-2419.2009.00509.x
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发表时间：
2009-01-01
影响因子：
2.6
通讯作者：
Hindell, Mark A.
中科院分区：
文献类型：
--
作者：
Bestley, Sophie;Gunn, John S.;Hindell, Mark A.
电子标签提供了关于高度洄游海洋捕食者的栖息地利用和行为的前所未有的信息，但很少有分析在动物行为与其海洋环境之间建立定量联系。在本文中，我们使用南方蓝鳍金枪鱼幼鱼（Thunnus maccoyii，SBT）的档案标签数据来（i）开发一种新方法，根据水柱结构（即来自标签的深度温度数据）来描述整个年度迁徙周期中使用的海洋栖息地，以及（ii）模拟SBT的垂直行为如何随栖息地类型和其他因素而变化。利用这种方法，我们确定了南印度洋亚热带环流南缘和亚南极锋北缘之间幼年 SBT 占据的八种栖息地类型。尽管鱼类内部和之间存在明显的高度变异性，但混合效应模型确定了对栖息地、月相、迁徙状态和昼夜期的一致行为反应。我们的结果表明，SBT 不会维持首选的深度或温度范围，而是表现出高度可塑性的行为来响应环境的变化。我们从潜在的直接原因（生理的、生态的）角度讨论了这种可塑性，并参考了种群评估中使用的基于生境的渔业数据标准化所面临的挑战。
Electronic tagging provides unprecedented information on the habitat use and behaviour of highly migratory marine predators, but few analyses have developed quantitative links between animal behaviour and their oceanographic context. In this paper we use archival tag data from juvenile southern bluefin tuna (Thunnus maccoyii, SBT) to (i) develop a novel approach characterising the oceanographic habitats used throughout an annual migration cycle on the basis of water column structure (i. e., temperature-at-depth data from tags), and (ii) model how the vertical behaviour of SBT altered in relation to habitat type and other factors. Using this approach, we identified eight habitat types occupied by juvenile SBT between the southern margin of the subtropical gyre and the northern edge of the Subantarctic Front in the south Indian Ocean. Although a high degree of variability was evident both within and between fish, mixed-effect models identified consistent behavioural responses to habitat, lunar phase, migration status and diel period. Our results indicate SBT do not act to maintain preferred depth or temperature ranges, but rather show highly plastic behaviours in response to changes in their environment. This plasticity is discussed in terms of the potential proximate causes (physiological, ecological) and with reference to the challenges posed for habitat-based standardisation of fishery data used in stock assessments.