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首页> 外文期刊>ICES Journal of Marine Science >School-based indicators of tuna population status
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School-based indicators of tuna population status

机译：基于学校的金枪鱼种群状况指标

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摘要

Theory and limited observation suggest that fish schools consist of more individuals of similar size when populations are large than when they are small. The hypothesis that population size might be indicated by school structure is tested for southern bluefin tuna (SBT), a commercially important large pelagic species, which has undergone an estimated 60% reduction in juvenile biomass since 1960. Fish size data are used to determine whether there have been changes in schooling behaviour that can be used as simple indicators of abundance. During tagging studies, juvenile SBT are removed sequentially from a school, measured, tagged, and released. These sequential size measurements are used here to describe school composition from different years in two locations using simple school metrics (including mean fish size, variance in size, and mean difference in size between sequential fish). Trends were significant in most metrics over the 40-year period analysed, and were inversely related to independent estimates of population size. Simple school metrics are cost-efficient and easily interpreted by stakeholders. Monitoring population trends in near real time through school composition metrics may indicate further decline or recovery of SBT and, therefore, assist future management of tuna and other schooling species.
机译：理论和有限的观察结果表明，种群数量多于鱼类种群少时，鱼群由更多类似大小的个体组成。对南方蓝鳍金枪鱼（SBT）（一种商业上重要的中上层鱼类）的种群结构可能表明种群规模的假设进行了检验，自1960年以来，该物种的少年生物量已减少了60％。鱼的大小数据用于确定是否上学行为发生了变化，可以用作简单的丰度指标。在标记研究期间，将少年SBT依次从学校中移除，测量，标记和发布。这些连续大小的度量在这里用于使用简单的学校指标（包括平均鱼的大小，大小的变化以及连续鱼之间的大小的平均差异）来描述两个位置不同年份的学校组成。在分析的40年中，大多数指标中的趋势都非常显着，并且与人口规模的独立估计值呈负相关。简单的学校指标具有成本效益，并且可由利益相关者轻松解释。通过学校组成指标近乎实时地监测人口趋势可能表明SBT进一步下降或恢复，因此有助于将来对金枪鱼和其他学校物种的管理。

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