Ecosystem-based management is a strategy that considers the entire ecosystem in management decision-making. The Coorong Dynamics Model (CDM) underpins an ecosystem-based approach to inform management of the Ramsar-listed Coorong wetland, South Australia. The CDM is a spatially resolved model that simulates environmental conditions within the Coorong, and is comprised of a core hydrodynamic model coupled to a water quality and habitat model. As the CDM can simulate a wide range of ecosystem variables at high spatial and temporal resolution, a challenge remained in the assessment and evaluation of masses of modelled outputs to inform ecosystem management.
To resolve this challenge a framework was developed to support the evaluation of modelled scenario outputs and guide the interpretation of expected ecological responses. Development of the framework followed six steps: (1) define management objectives for the ecosystem, (2) identify critical ecosystem components, processes and services (CPS) and key threats, (3) identify indicators (biological, chemical and physical factors) that influence the status of each critical CPS and key threat, (4) identify indicator reference points (quantitative measures) that are reflective of important changes in the status of critical CPS and key threats to the strengthening of an indicator, (5) evaluate confidence in the CDM simulating indicator reference points, and (6) summarise and evaluate model outputs with indicator reference points for each critical CPS and key threat.
The framework is a tool capable of summarising CDM outputs in a manner that is quantitative, ecologically meaningful, timely, transparent, repeatable and accounts for uncertainty in predictions. Flexibility inherit within the framework ensures that it can be iteratively updated as new data and information become available and can inform water policy, management and decision-making. The framework serves as tool for continual improvement in the evidence-based management of the Coorong ecosystem.