Regime Shifts: Methods of Analysis

Abstract

The identification and detection of regime shifts pose many challenges. While there is general agreement that a regime shift consists of a restructuring of a marine ecosystem, the form of restructuring that constitutes a regime shift remains under debate. At present, we identify regime shifts through exploratory data analysis but what types of data are appropriate and how should the data be treated. There are many different possible variables to consider in describing a marine ecosystem. There are even many different categories of variables: physical, biogeochemical, habitat, and organismal (from bacteria and plankton through zooplankton to fish). It is possible to consider hundreds or indeed thousands of variables for a given marine ecosystem. Given the complexity of regime shifts, and the potential for misidentification, the selection of the data, and the approach taken to the analysis are important. The results of the analysis of very complex data sets can be quite sensitive to the approach taken to the analysis.