Characterising Regime Shifts in the Marine Environment: A North Atlantic Perspective

No abstracts are to be cited without prior reference to the author.

Recent years have seen a plethora of studies reporting that ‘regime shifts’ have occurred in the marine environment during the last century. In many cases the criteria used to distinguish a ‘regime shift’ have not been explicitly stated. In other cases a formal definition has been proposed and the data set assessed against it. Unfortunately, many studies have advanced a novel definition of a ‘regime shift’, which have resulted in a degree of circularity in the argument, are rarely quantitative, and do not distinguish between climatic and ecological regime shifts. Consequently, they throw little light on the drivers of ecological ‘regime shifts’. Characteristics of regime shifts emergent from a review of well-documented marine regime shifts purported to have occurred around the world are reported and used to explore causal drivers of North Atlantic regime shifts. The resulting set of ‘standard criteria’ are applied to recently observed extreme negatives in North Atlantic climate indices and predicted changes in biological communities are considered based on patterns observed following the late 1980s North Atlantic regime shift.