Illegal fishing, unregulated bycatch, and market demand for certain products (e.g., fins) are largely responsible for the rapid global decline of shark and ray populations. Controlling trade of endangered species remains difficult due to product variety, taxonomic ambiguity, and trade complexity. The genetic tools traditionally used to identify traded species typically target individual tissue samples, and are time-consuming and/or species-specific. Here, we performed high-throughput sequencing of trace DNA fragments retrieved from dust and scraps left behind by trade activities. We metabarcoded “shark-dust” samples from seven processing plants in the world's biggest shark landing site (Java, Indonesia), and identified 61 shark and ray taxa (representing half of all chondrichthyan orders), more than half of which could not be recovered from tissue samples collected in parallel from the same sites. Importantly, over 80% of shark-dust sequences were found to belong to CITES-listed species. We argue that this approach is likely to become a powerful and cost-effective monitoring tool wherever wildlife is traded.

中文翻译：

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鲨鱼尘：应用加工残留物的高通量 DNA 测序来监测受威胁的鲨鱼和鳐鱼的贸易

非法捕捞、不受管制的兼捕以及对某些产品（例如鱼翅）的市场需求是全球鲨鱼和鳐鱼种群数量迅速下降的主要原因。由于产品多样性、分类学模糊性和贸易复杂性，控制濒危物种贸易仍然很困难。传统上用于识别贸易物种的遗传工具通常针对单个组织样本，并且非常耗时且/或具有物种特异性。在这里，我们对从贸易活动留下的灰尘和废料中回收的痕量 DNA 片段进行了高通量测序。我们对来自世界上最大的鲨鱼登陆点（印度尼西亚爪哇）的七个加工厂的“鲨鱼尘”样本进行了元条形码编码，并鉴定了 61 个鲨鱼和鳐类群（占所有软骨鱼类的一半），其中一半以上无法恢复来自从同一地点平行收集的组织样本。重要的是，超过 80% 的鲨鱼尘序列被发现属于 CITES 所列物种。我们认为，无论在哪里进行野生动物交易，这种方法都可能成为一种强大且具有成本效益的监测工具。