The resilience of marine systems is a function of the structure of the ecosystems (such as the types and numbers of species they contain), the components and functions of the habitats that support those species, and the interaction of this ecological system with physical attributes such as the dynamics of the ocean currents.
Assessing the resilience of marine systems is based on the concept that resilient systems do not remain unchanged, but that change occurs within limits. Resilience of ecosystems can be assessed by asking:
- What has been the past resilience of the system? What evidence is there of past resilience?
- What are the known pressures that will have to be dealt with? Is the management system prepared to deal with, or respond to, these anticipated pressures?
- Are the attributes of the ecosystems in good shape to permit a favourable response to unpredicted pressures or changes that may arise? Are the factors that affect the capacity to deal with surprises intact?
Keeping ecosystems resilient is an important attribute of ecosystems and a common generic goal of management, but rarely can resilience itself be quantified or measured. There are no national-scale reporting systems or datastreams that can provide useful surrogates to measure or report on the resilience of marine ecosystems, habitats or species. This section considers some of the important attributes of resilient systems in relation to the management of marine issues.