Anticyclonic Eddies Aggregate Pelagic Predators in a Subtropical Gyre
September 07, 2022
Using a large-scale fishery dataset in the North Pacific Subtropical Gyre, we show a pervasive pattern of increased pelagic predator catch inside anticyclonic eddies relative to cyclones and non-eddy areas.
Ocean eddies are coherent, rotating features that can influence pelagic ecosystems across many levels. These features may increase productivity of nutrient-poor regions, accumulate prey and effect habitat conditions in the water column. However, in nutrient-poor subtropical gyres—the largest marine biome—the role of eddies in influencing behaviour throughout the pelagic predator community remains unknown despite predictions for these gyres to expand and pelagic predators to become increasingly important for food security.
Our results indicate that increased mesopelagic prey abundance in anticyclone cores may be attracting diverse predators, forming ecological hotspots where these predators aggregate and exhibit increased abundance. In this energetically quiescent gyre, we expect that isolated mesoscale features (and the habitat conditions in them) exhibit primacy over peripheral submesoscale dynamics in structuring the foraging opportunities of pelagic predators. Our finding that eddies influence coupling of epi- to mesopelagic communities corroborates the growing evidence that deep scattering layer organisms are vital prey for a suite of commercially important predator species and, thus, provide valuable ecosystem services.
Arostegui MC, Gaube, P, Woodworth-Jefcoats PA, et al.. 2022. Anticyclonic eddies aggregate pelagic predators in a subtropical gyre. Nature (2022) https://doi.org/10.1038/s41586-022-05162-6.