Regime shifts are characterized by sudden, substantial and temporally persistent changes in the state of an ecosystem. They involve major biological modifications and often have important implications for exploited living resources.
In this study, we examine whether regime shifts observed in 11 marine systems from two oceans and three regional seas in the Northern Hemisphere (NH) are synchronous, applying the same methodology to all. We primarily infer marine pelagic regime shifts from abrupt shifts in zooplankton assemblages, with the exception of the East Pacific where ecosystem changes are inferred from fish.
Our analyses provide evidence for quasi-synchronicity of marine pelagic regime shifts both within and between ocean basins, although these shifts lie embedded within considerable regional variability at both year-to-year and lower-frequency time scales. In particular, a regime shift was detected in the late 1980s in many studied marine regions, although the exact year of the observed shift varied somewhat from one basin to another.
Another regime shift was also identified in the mid- to late 1970s but concerned less marine regions. We subsequently analyse the main biological signals in relation to changes in NH temperature and pressure anomalies. The results suggest that the main factor synchronizing regime shifts on large scales is NH temperature; however, changes in atmospheric circulation also appear important.
We propose that this quasi-synchronous shift could represent the variably lagged biological response in each ecosystem to a large-scale, NH change of the climatic system, involving both an increase in NH temperature and a strongly positive phase of the Arctic Oscillation. Further investigation is needed to determine the relative roles of changes in temperature and atmospheric pressure patterns and their resultant teleconnections in synchronizing regime shifts at large scales.
General news | 2017-12-12
See video from eminar with Professor Rashid Sumaila, one of the world’s most innovative researchers on the future of the oceans
Research news | 2017-11-30
The PECS-II conference showcased place-based research and how it can help us work towards global sustainability in the Anthropocene
Research news | 2017-11-28
How urban greening and civic ecology projects can improve human well-being and restore crucial ecosystem services
Research news | 2017-11-27
What plantain farmers in Costa Rica can teach us about the inconsistent links between access to ecosystem services and well-being
Research news | 2017-11-23
Centre science director well established among world’s most top-cited and influential scientists
Research news | 2017-11-21
Large-scale changes in Arctic marine food web can be expected within 50 years, some good, but in the long run several critical