New approaches to simulating the complex interaction effects of multiple human impacts on the marine environment

The interplay of anthropogenic effects presents significant challenges to modelling and managing marine resources. The increasing awareness of the complexity of the interaction of human impacts has led to a demand for end-to-end (E2E) models that attempt to include all major processes in a single framework. These whole-of-system models are potentially very useful as numerical laboratories to explore the potential spectrum of responses from the interplay of anthropogenic effects. However, despite their limitations and early stage of development, the output of E2E models is under increasing social pressure to provide “simple” answers to highly complex problems. Here, we suggest some approaches that can be included in E2E models for considering the potential effects of complex interactions on community and ecosystem services. We show how assumptions and parameterizations made in existing E2E models can be altered to allow processes to shift with the dynamic response to both natural and human drivers. Alternative ways for interpreting complex model output, non-linearity, handling uncertainty, and how to include multispecies interaction effects within a framework of ecosystem-based management are suggested. We point out parts of the marine system that have been neglected in model development, but now should be included to understand interaction effects from multiple anthropogenic stressors. The E2E model framework also needs to be further expanded from an often-skewed focus on ecological systems to a more even-handed treatment of socio-ecological systems, including cultural aspects. Future progress in E2E models will require an interdisciplinary framework involving both qualitative and quantitative approaches, closer cooperation between empiricists and modellers, and the development of consistent terminology.