What a massacre! What a feast! Of hotspots and blind spots!
"With a new mapping method, MIT scientists observed millions of capelin fish shoaling off the Norwegian coast. A vast swarm of cod devoured the capelin, in the largest predation event yet recorded. ..."
From the abstract:
"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."
Fig. 1: Instantaneous wide area population density images of overlapping species showing transition from random individual behaviour to ordered adversarial group behaviour in rapid formation and propagation of capelin prey and engulfing cod predator shoals.
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