Marine Ecosystem Science on an Intertwined Planet.

Marine ecosystem science has developed since the 1940s, when humans obtained the ability to spend substantial time underneath the surface of the ocean. Since then, and drawing on several decades of scientific advances, a number of exciting research frontiers have emerged. We find: Under- standing interacting drivers of change, Identifying thresholds in ecosystems, and Investigating social-ecological dynamics to represent particularly interesting frontiers, which we speculate will soon emerge as new mainstreams in marine ecosystem science. However, increasing human impacts on ecosystems everywhere and a new level of global connectivity are shifting the context for studying, understand- ing, and managing marine ecosystems. As a consequence, we argue that ecosystem scientists today also need to address a number of critical challenges and devote new energy and expertise to Modeling the Anthropocene, Operationalizing resilience, and Understanding social-ecological dynamics across scales. This new deep dive into unknown waters requires a number of strategies to be successful. We suggest that marine ecosystem scientists need to actively: Prepare for the unexpected, cross boundaries, and understand our cognitive limitations to further develop the exciting field of marine ecosystem science.