Paradoxical regional contrasts in the resilience of marine zooplankton to climatic warming

To investigate the integrated response of plankton to climate warming, we measured simultaneous shifts in abundance, geographic range and phenology of eight copepod taxa across the North Sea and NE Atlantic over 6 decades. Here we show that the North Sea warmed about twice as rapidly as the NE Atlantic, yet its species showed greater resilience, maintaining more stable abundance and ranges. In contrast, the NE Atlantic experienced declining copepod populations and greater range shifts (up to 139 km northwards per decade). Regionally specific conditions (high food abundance and/or advection) in the North Sea, may have contributed to this resilience. Most taxa exhibited consistent seasonal shifts with warming (up to ~39 days earlier °C-1) in both areas. In the North Sea, species with greater range shifts also had more pronounced phenological shifts, suggesting a link between the two responses. Climate - smart marine management needs to incorporate this variable ecosystem resilience under warming, moving beyond temperature-centric models of the stability of ecosystems.