Early warning indicators are one of the fastest-growing fields in applied ecology. These indicators are based on theoretical predictions that key ecosystem parameters should follow predictable trends – like becoming more variable – as a sudden ecosystem reorganization becomes more likely. Monitoring changes in system properties such as population variability is therefore expected to give managers "early warning” that the system is approaching a tipping point into a less-desired state.

Early warning indicators have mostly been developed with mathematical models, laboratory experiments and studies of simple ecosystems like freshwater ponds. Our research concentrates on the next frontier - determining whether early warning indicators will work in the large, complicated settings that managers are concerned with, like ocean ecosystems. Support from The Pew Charitable Trusts allowed us to demonstrate, in a forthcoming paper in Ecosphere, which kinds of ecosystem change are most likely to produce early warnings. Additionally, a new project funded by the NOAA Fisheries and the Environment Program will summarize available time series from the Bering Sea, Gulf of Alaska and California Current to develop early indicators for biological response to the “warm blob” and other ecosystem perturbations.

Figure: The explosion in published studies on early warning indicators during 2006-2015.