Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, USA.
Institute of Marine Research, Post Office Box 1870, Bergen, Norway.
Commun Biol. 2024 Oct 29;7(1):1386. doi: 10.1038/s42003-024-06952-6.
Sensing limitations have impeded knowledge about how individual predator-prey interactions build to organized multi-species group behaviour across an ecosystem. Population densities of overlapping interacting oceanic fish predator and prey species, however, can be instantaneously distinguished and quantified from roughly the elemental individual to spatial scales spanning thousands of square kilometres by wide-area multispectral underwater-acoustic sensing, as shown here. This enables fundamental mechanisms behind large-scale ordered predator-prey interactions to be investigated. Critical population densities that transition random individual behaviour to ordered group behaviour are found to rapidly propagate to form vast adversarial prey and predator shoals of capelin and surrounding cod in the Barents Sea Arctic ecosystem for these keystone species. This leads to a sudden major shift in predator-prey balance. Only a small change in local behaviour triggers the shift due to an unstable equilibrium. Such unstable equilibria and associated balance shifts at predation hotspots are often overlooked as blind spots in present ocean ecosystem monitoring and assessment due to use of highly undersampled spatio-temporal sampling methods.
感知能力的局限性阻碍了我们对单个捕食者-猎物相互作用如何在整个生态系统中构建到有组织的多物种群体行为的了解。然而，通过广域多光谱水下声学传感，可以即时区分和量化重叠相互作用的海洋鱼类捕食者和猎物物种的种群密度，从基本的个体到跨越数千平方公里的空间尺度，如图所示。这使得可以研究大规模有序的捕食者-猎物相互作用背后的基本机制。研究发现，临界种群密度会迅速传播，形成广阔的敌对鳕鱼和毛鳞鱼群，从而使关键物种巴伦支海北极生态系统中的随机个体行为转变为有序的群体行为。这导致了捕食者-猎物平衡的突然重大转变。由于不稳定的平衡，仅当地行为的微小变化就会引发这种转变。由于使用高度欠采样的时空采样方法，这种不稳定的平衡和相关的捕食热点的平衡转变经常被忽视，成为当前海洋生态系统监测和评估中的盲点。
