Mission impossible: unlocking the secrets of coral reef fish dispersal
Mission impossible: unlocking the secrets of coral reef fish dispersal
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不可能的任务：解开珊瑚礁鱼类扩散的秘密
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发表时间：
2015
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通讯作者：
G. Jones
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作者：
G. Jones
在过去 15 年里，我们对珊瑚鱼幼虫每一代的传播距离和方向的了解已经发生了变化。各种方法的新发现，包括幼虫的化学标记、遗传亲子分析、种群水平的遗传分析、耳石化学特征和生物物理模型，都表明幼虫在离家较近的地方定居的比例比以前认为的要高。相对扩散频率似乎随着距源的距离而下降，虽然平均扩散距离可能很小，但扩散核可能有长尾。自我招募水平随着隔离或捕获而增加，而水动力强迫将拉长大型海洋系统中的扩散尾部。中上层幼虫持续时间 (PLD) 不同的物种具有广泛重叠的扩散核心，尽管具有较长 PLD 和中上层卵的物种可以进一步扩散。新的情况表明，珊瑚礁鱼类种群对当地干扰具有天生的适应能力，当地管理可以实现生物多样性保护和渔业目标。亲子分析似乎是描述完整扩散核、验证其他遗传方法以及生物物理和空间明确的人口模型的最有前途的方法。面对日益增加的人类压力，必须强调识别和保护关键亚群，以实现元种群的持久性。
确定珊瑚礁鱼类幼虫在产卵和定居到珊瑚礁之间的短暂时间内的去向曾经被认为是不可能的。然而，对于所有生物体来说，世代之间的联系对于理解种群如何持续存在、物种如何适应环境以及它们如何受到人类行为的影响至关重要。在 20 世纪 90 年代之前，在第一本关于珊瑚礁鱼类生态学的书 [2230] 中，珊瑚礁鱼类种群被认为是“开放的”，通过海洋流驱动的幼虫长距离扩散连接起来。当时，证据似乎很有说服力。众所周知，中上层幼虫持续时间 (PLD) 可以持续数周 [1443, 2571]，在此期间，洋流可以将幼虫运送到海洋各地 [1411]。
Our knowledge of the distance and directions that reef fish larvae disperse each generation has been transformed over the last 15 years. New discoveries from a diversity of approaches, including chemical tagging of larvae, genetic parentage analysis, population-level genetic analyses, otolith chemical signatures, and biophysical modeling, have all indicated a higher proportion of larvae settle closer to home than previously thought. The relative dispersal frequencies appear to decline with distance from source, and while average dispersal distances may be small, dispersal kernels are likely to have a long tail. Levels of self-recruitment increase with isolation or entrapment, while hydrodynamic forcing will stretch the dispersal tail in large oceanic systems. Species that differ in pelagic larval durations (PLDs) have broadly overlapping dispersal kernels, although species with longer PLDs and pelagic eggs can disperse further. The emerging picture suggests reef fish populations have an innate resilience to local disturbances and that local management can achieve both biodiversity conservation and fisheries objectives. Parentage analysis appears to be the most promising approach for describing full dispersal kernels, validating other genetic approaches, and biophysical and spatially explicit demographic models. Emphasis must be placed on identifying and protecting key subpopulations for meta population persistence in the face of increasing human pressures.
The task of establishing where coral reef fish larvae go in that brief period between spawning and settlement to the reef was once considered impossible. Yet for all organisms, the link between generations is fundamental to understanding how populations persist, how species adapt to their environment, and how they are affected by human actions. Prior to the 1990s and in the first book on the ecology of coral reef fishes [2230], reef fish populations were assumed to be "open", connected by larval dispersal over long distances driven by oceanic flows. At the time, the evidence seemed convincing. It was known that the pelagic larval duration (PLD) could last for weeks [1443, 2571] and in that time currents could transport larvae across oceans [1411].