An Ecosystem Approach to marine management is advocated globally by international bodies including the Convention on Biological Diversity, the Food and Agriculture Organization of the UN, and the European Union. In response, a plethora of computer-driven marine ecosystem models have been developed worldwide. The existence of multiple models has been recognized as an asset, notably due to higher confidence in convergent model results and a better cross-disciplinary understanding of model functioning in general.
Increasingly, researchers have been taking advantage of the proliferation of models to use a multi-modelling approach to inform environmental management in uncertain scenarios. Multi-modelling approaches such as model envelopes have been used for climatic predictions (IPCC2014) at the global scale, where similar-yet-different Earth System Models are used to draw envelopes of possible trajectories of global temperature under different Representative Concentration Pathway scenarios, thus integrating model uncertainty into the different projections. These multi-modelling approaches rely on addressing a single question with several ecosystem models defining common scenarios and applying them to different models. However, imposing a common scenario might lead to an under-use of model potential, or drift the model too far from its original scope and validated application. In these conditions, the comparison of models’ outputs fails to provide accurate information on both the core question being investigated and the models’ functionality.
The EuroMarine-funded foresight workshop M3E will seek to address this drawback of multi-modelling approaches by evaluating an alternative framework where different scenarios are designed for each model in order to answer a common question from different angles, as most appropriate per model. This new framework for multi-model comparison produces complementary results, providing insights on different aspects of ecosystem response to pressures,while providing areas of overlap among models that can compare model functioning. The M3E approach thus extracts the maximum potential use from available models.
The foresight workshop will:
- Establish a framework for defining a variety of scenarios adapted to the variety of model types that can be used to answer a common question.
- Propose guidelines to compare outputs of the same ecological compartment from different models, including determining the most appropriate levels of aggregation (temporal / spatial / functional groups),the most appropriate time horizon (short, medium, and/or long-term) and the most appropriate metrics (e.g. absolute or values, ranking, trends).
- Explore how to synthesize results in a single picture following a standardized process based on model relevance to provide management advice.
The organisers expect the workshop will lead to multiple publications relevant to the field. In particular, they expect to produce:
- A position paper presenting their alternative framework for multi-modelling. This paper will include a literature review of existing multi-models initiatives as context, and will propose a methodology to better use multiple models associated with scenarios variations in order to offer a more complete view of the ecosystem response to management questions. This methodology will be illustrated by a case study to outline how the different aspects of the key question being examined could be answered by each relevant modelling tool.
- One or two research papers applying this alternative multi-model framework to particular case studies and associated management questions. Possible candidates include southern Benguela, the Bay of Biscay and eastern English Channel ecosystems, where several models already exist (including ecosystem models Atlantis, OSMOSE and Ecopath, fleet dynamic models such as ISIS-Fish and bio-economic models such as IAM), but other ecosystems could be considered depending on participants. Possible management questions to be addressed include marine spatial planning (including multiple anthropogenic uses), harvest control rules and new policies such as the EU landing obligation.
The organisers expect that the outcomes of this workshop will provide the scientific community with an alternative multi-modelling methodology, using existing models according to their operational capacities. Additional impact is expected within the marine management community, which has been awaiting more appropriate models to evaluate the performances of management scenarios. Depending on the outcomes of the foresight workshop, funding for a broader project will be sought to generalize the proposed M3E framework and further develop methodologies associated with the identification of the right levels of aggregation and identification of synthesizing method to offer a global picture.