by Sheril Kirshenbaum
Hughes, T. P., D. R. Bellwood, et al. (2005). “New paradigms for supporting the resilience of marine ecosystems.” Trends in and Evolution 20(7): 380-386.
A principle element of the article deals with the concept of phase shifts. These occur when stresses on a system and climate change result in dramatic shifts in species composition. Many historical conservation and management practices have been based on the notion that reducing current stress will automatically bring back original system conditions in a reasonably short time. However, this assumption ignores archeological and historical data on the ways marine ecosystems have been altered by our activities. “Recovery” may mean a different state altogether that prevents return to the original. As Hughes et al. point out, the management implications are tremendous because it is sustaining a resilient system is much easier than repairing it after a phase shift. Socio-economics are now beginning to acknowledge these concepts of alternate states, resilience and scale in developing theory for SESs to prevent phase shifts.
When a phase shift occurs, it may result in an alternate stable state. The new system may achieve a different level of equilibrium making it difficult or no longer possible to reverse to the original ‘Healthy state’ before the perturbation took place.
Hughes et. al. propose four key attributes to successful SES management which echo similar principles widely supported in the marine management realm. They highlight managing for uncertainty, building a knowledgebase, thinking in terms of a complex adaptive system, ecological feedback, supporting flexible institutions and social networks across levels of governance.