Unexpected ecosystem change: the role of multiple stressors and underlying mechanisms

Abstract

There is a rapidly increasing interest in both predicting and understanding the effects of climate change in marine ecosystems. Yet, this current flurry of research often ignores the effects of the combination of multiple stressors, in particular where local stressors (e.g. nutrient pollution) will combine with the increase in temperature and CO2. While these stressors in isolation can have relatively small effects on individual fitness and system function, when combined they can drive catastrophic system collapse. I will draw together recent work to identify the effects of multiple stressors in subtidal marine systems and discuss how they can drive ecosystem shifts. I will then discuss how recognition of the underlying physiological mechanisms and functional role of key species can be used to identify the potential for ecosystem shifts before they occur and management tools that can limit their impact.