In this post we talk about a critical review entitled “Resilience in Ecotoxicology – towards a multiple equilibrium concept”.

This critical review discusses the resilience concept in the context of ecotoxicology with the ultimate aim of initiating a debate on the value of this concept for chemical stress-related research and ultimately the risk assessment of chemicals.

The concept of ecological resilience (graphic by M. Bundschuh)

As the term resilience describes stress-response patterns and has been adopted in several scientific disciplines, we discuss its potential merits for ecotoxicology. We start by defining resilience based on underlying mechanistic assumptions: engineering resilience (rebound) is used to describe the ability of organisms and systems to recover from adverse conditions (disturbances). Engineering resilience – the prevailing view of resilience in ecotoxicology – is thus defined as the rate of recovery. By contrast, the ecological resilience definition considers a systemic change; that is, when ecosystems reorganize into a new regime following disturbance. Under this new regime, structural and functional aspects can change considerably relative to the previous regime. Hence, the system does not recover in the classical sense. In this context, resilience can be considered as an emergent property of complex systems.

Although the differences of both definitions seem subtle, the implications and uses differ strongly. We argue that both definitions and uses have their place in ecotoxicology. While the usefulness of engineering resilience seems clear from ecotoxicological research in the last decades, ecological resilience may be useful for describing systemic ecological changes caused by chemical stress. Finally, we contend that engineering and ecological resilience help to distinguish ecotoxicological responses to chemical stressors mechanistically and, as such, may have implications for theory, policy and regulation.

The paper was authored by Mirco Bundschuh, Ralf Schulz and Ralf B. Schäfer, together with colleagues from the US (Craig R. Allen) and Sweden (David G. Angeler), and is published in Environmental Toxicology and Chemistry.