Sentinel Sharks: tracking anthropogenic contamination in the marine ecosystem

在上个世纪，人为活动迅速增加了进入海洋环境的金属流入，这些金属可以在海洋顶级消费者中进行生物积累和生物放大。这可能会引起亚致死效应，对人类海产品消费者产生广泛影响。鲨鱼的椎骨可以提供它们生活的水域的终身记录，这意味着鲨鱼可能在很长一段时间内充当人类影响的哨兵。我们将使用来自英国各地的捕鱼垃圾，对一种顶级海洋捕食者——小斑点猫鲨进行金属暴露取样。我们将通过在英国各地水质不同的地方取样软组织和鲨鱼椎骨来比较当前和历史的金属暴露。在分析椎骨时，我们将评估“人类暂停”（由于SARS - CoV-2导致的人类活动质量减少）对海洋顶级捕食者污染物的影响。此外，我们将测试寄生虫以不同于宿主的速度积累金属的假设，这可能对鲨鱼的健康有益。我们将采用激光烧蚀等离子体源质谱法（LA-ICP-MS）测定鲨鱼椎骨、组织和寄生虫的微量元素组成，并将其与生态标记物进行比较。通过这样做，我们将能够确定哪些元素可用于追踪人为水污染，它们对人为污染变化的敏感性以及寄生在生物积累中的作用。工作将由来自卡迪夫和埃克塞特大学的跨学科团队监督，该团队由生态学家，渔业专家和地球化学家组成，并由利益相关者管理小组加入；Cefas。

Over the last century anthropogenic activities have rapidly increased the influx of metals entering the marine environment, which can bioaccumulate and biomagnify in marine top consumers. This may elicit sublethal effects, having broad implications for human seafood consumers. Shark vertebrae can provide a lifelong record of the water in which they dwell, implying that sharks may act as sentinels of anthropogenic influences over a long time. Using fishing discards from across the UK we will sample metal exposure in a top marine predator, the small-spotted catshark Scyliorhinus canicula. We will compare current and historic metal exposure by sampling soft tissues and shark vertebrae at locations across the UK that differ in water quality. In analysing vertebrae, we will assess the impact of the 'anthropause' (the mass reduction in anthropogenic activities due to SARS CoV-2) on contaminants in marine top predators. In addition, we will test the hypothesis that parasites accumulate metal at a different rate than the host, potentially providing a fitness benefit to the shark. We will use laser ablation plasma source mass spectrometry (LA-ICP-MS) to determine the trace element composition of shark vertebrae, tissue and parasites and compare this to ecological markers. In doing so, we will be able to identify which elements can be used to trace anthropogenic water pollution, their sensitivity to changes in anthropogenic pollution and the role of parasitism in bioaccumulation. Work will be supervised by an interdisciplinary team from Cardiff and Exeter University consisting of ecologists, fishery experts and geochemists joined by a stakeholder management group; Cefas.