标记重捕法在中华白海豚种群动态研究的应用及建议

Mark-recapture technique for demographic studies of Chinese white dolphins—applications and suggestions

早期的中华白海豚考察主要依赖样线调查法了解其资源分布,而近期研究更多采纳标记重捕法获取种群动态信息。在辨识个体的基础上,后者能够获取多种种群参数开展种群生存力分析。本文回顾在我国海域开展的中华白海豚种群动态研究进展及各地区种群标记重捕数据的累积情况;通过数据模拟评估努力值如何影响种群大小统计的误差和偏差;综合阐述野外考察方案设计、标志筛选和数据处理对数据分析的潜在影响;强调模型拟合优度检验和模型选择的重要性;最后,针对比较不同时期或不同方法获取中华白海豚种群信息时的常见误解提出我们的意见。本文旨在帮助完善我国中华白海豚的后期资源监测工作。

Early studies of Chinese white dolphins applied primarily line-transect survey techniques to acquire distribution data and generate abundance estimates, while many recent studies rely on mark-recapture techniques to gain insights into population dynamics and demography. The application of an individual photo-identification approach provides the means to estimate vital population parameters with mark-recapture models which in turn facilitate population viability analysis. Here, we review the application of the photographic mark recapture technique in demographic studies of Chinese white dolphins in China waters; we summarize the quality assessment of individual mark recapture databases; ran simulations to evaluate how survey effort may impact the accuracy and precision of population size estimates; discuss how the survey design, selection of individual-ID marks and data filtering may impact the mark-recapture analysis; and we point out how to minimize the bias associated with data over-dispersion through model selection according to goodness-of-fit testing. We discuss also conceptual challenges that may lead to misinterpretation of data when comparing results from different studies that used different field techniques. With improved understanding of analytical principles behind the data gathering, we hope that demographic studies of Chinese white dolphins in the region will expand and improve in the near future.