Large-scale climate control of zooplankton transport and biogeography in the Kuroshio-Oyashio Extension region

We studied decadal-scale climate control of zooplankton biogeography driven by Kuroshio Extension (KE) dynamics using long-term zooplankton data and an advection model driven with currents from the Earth Simulator eddy-resolving ocean model. Passive tracer model experiments indicated that warm-water species transported from the south were retained in the Kuroshio-Oyashio Extension (KOE) region during years with a weak KE. A 2.5year lag in the North Pacific Gyre Oscillation (NPGO) index was significantly correlated with the KE strength and with warm-water species abundance. These findings indicate that climate signals from the central and eastern North Pacific propagated westward, influencing not only transport in the KOE region but also regional ecosystem variability. Because the NPGO controls important aspects of the transport dynamics and ecosystem variability in the eastern North Pacific, this study provides additional evidence that large-scale climate patterns drive coherent changes in ecosystems throughout the North Pacific by impacting regional-scale transport dynamics.