Multi-predatory feeding aggregations in the Norwegian Sea: prevalence and ecological importance

Multi-predatory feeding aggregations (MPFAs) occur when several predator species concurrently exploit shared, spatially and temporally aggregated prey. Although MPFAs are well described in some marine ecosystems, their prevalence in the Norwegian Sea has historically been underestimated. Here, we synthesize existing biological, acoustic, visual and behavioural evidence to reinterpret classical predator-prey observations through the lens of MPFAs. Our reassessment revealed that numerous events previously described as single-predator interactions actually represent multi-species feeding assemblages involving marine mammals, large predatory fishes and seabirds. These MPFAs primarily target highly abundant pelagic schooling fishes, such as Norwegian spring-spawning herring, northeast Atlantic (NEA) mackerel, blue whiting and capelin. We compiled, to our knowledge, the first region-wide overview of documented and inferred MPFAs in the Norwegian Sea, characterizing species assemblages, ecological settings and behavioural mechanisms. We further discussed how predator physiology, group foraging strategies, prey schooling dynamics and oceanographic features interact to create conditions favourable for MPFAs. Recognizing MPFAs as common and ecologically influential phenomena has important implications for understanding food webs and ecosystem-based fisheries management. Therefore, we recommend that future research in the region explicitly incorporate MPFAs through multi-sensor observational approaches, behavioural analyses and integration into ecosystem models to better represent the functional role of predators in the NEA. This article is part of the theme issue 'Multi-predator feeding aggregations in pelagic waters'.