Most management systems aimed at maintaining or enhancing resilience in components of the marine environment focus on reducing the cumulative nature of multiple impacts and avoiding dramatic shifts in species composition, also known as regime shifts. This is because such shifts are often long-lasting and difficult to reverse (Hughes et al. 2005). However, there are few practical tools available to managers for anticipating and responding to such shifts across the broader environment (Levin & Möllman 2015).
Two useful tools for building resilience in larger socio-ecological systems are structured scenarios and active adaptive management (Folke et al. 2002). Socio-ecological systems are constantly changing, often unpredictably. A way of assessing potential impacts and the management systems that might be required to address these impacts is to investigate a range of scenarios producing projections or if–then case studies (e.g. if we follow a certain scenario, then this is the expected outcome for the future; Evans et al. 2015). Prominent examples of such scenario investigations are those for climate change conducted by the Intergovernmental Panel on Climate Change (IPCC), where a range of scenarios of greenhouse gas emissions, and the associated impacts on atmospheric terrestrial and marine systems are examined (IPCC 2014). By envisaging multiple alternative futures and actions that might attain or avoid particular outcomes (i.e. mitigative measures), resilience-building management policies can be identified that slow, or even reverse, undesired change (Folke et al. 2002).
Management that builds resilience can sustain socio-ecological systems in the face of surprise, unpredictability and complexity. Because of the unpredictability of change often occurring within these systems, any management frameworks aimed at building or maintaining resilience need to be flexible and open to learning through evaluation. They also need to have the capacity to innovate to ensure that any changes are responded to on relevant temporal and spatial scales (Folke et al. 2002). Governance may also need to be adaptive, crossing jurisdictional and sectoral boundaries as new information, such as that on cumulative impacts, becomes available (Schultz et al. 2015). Management frameworks require clearly articulated and defined management objectives, including desired future ecosystem states (Figure MAR40)—for example, a healthy, functioning reef. Key indicators that can be used to monitor the trajectory of the ecosystem against these objectives need to be identified (Hedge et al. 2013; see also Box MAR11) and, in association, reference points or thresholds that the system is to be maintained above. Assessments of the risk that these reference points or thresholds might be exceeded should be carried out (e.g. Hobday et al. 2011). Finally, modelling approaches for evaluating the consequences of differing management strategies in responding to changes to the system should be incorporated into the framework.