Editorial: Managing for the Future: Challenges and Approaches for Disentangling the Relative Roles of Environmental Change and Fishing in Marine Ecosystems

7 pages, 1 figure.-- This RT originated from a session led by the CoArc project at the IMBeR 2019 Open Science Conference, Future Oceans2, held in Brest, France on 17-21 June 2019In the Anthropocene era, characterized by significant human impact on Earth's systems, the old saying “plus ça change, plus c'est la même chose” does not apply to the natural world. The oceans, long held to be relatively stable physically, biogeochemically and ecologically, are warming, acidifying, and de-oxygenating (Gruber, 2011; IPCC, 2019; Kwiatkowski et al., 2020). In short, marine ecosystems are changing (Doney et al., 2012; Hollowed et al., 2013; Gao et al., 2019), and in some areas of the globe, the change is very rapid (Henson et al., 2017; Johnson and Lyman, 2020). At the same time, human-induced stressors such as fisheries and pollution continue, with sometimes dramatic observed and predicted declines in commercial stocks (e.g., Vasilakopoulos et al., 2014; Lotze et al., 2019). Therefore, in the 21st century, fisheries and ocean managers require science advice that accounts for the cumulative effects of multiple stressors, fisheries removals, human-induced climate change, anthropogenic stressors, environmental variability, and trophic dynamics. Ongoing climate change and increasing pressure to intensify Blue Growth and the Blue Economy highlight the immediacy of the situation. There is strong need to better understand the impacts of these stressors and ecosystem variability so that we may proactively contribute to the management process. In parts of the world, such as the data rich northern hemisphere, over a century of monitoring marine fisheries and ecosystems has produced a substantial database from which to study ecosystem response to climate change. This has contributed to the development of policies for sustainable management of fisheries and ecosystems, and in some jurisdictions, development of ecosystem-based action plans, such as the Baltic Sea Plan (HELCOM, 2007) and the Norwegian Sea Integrated Management Plan (Norwegian Ministry of Climate and Environment, 2017). In other parts of the world where there may be lower availability of observational data, shorter time series and fewer resources, the challenge of understanding ecosystem variability and thus managing for the future may be greater. To date, we have had some success describing variability on multiple scales of space and time, and from the genetic to the ecosystem levels (e.g., Rijnsdorp et al., 2009; Petitgas et al., 2018). Managing for the future to mitigate the impacts of human-induced ecosystem change requires that we incorporate this variability, and its consequences, into management policies. This requires integration of empirical studies, modelling and the development of system indicators that describe relevant variability and change. This Frontiers research topic (RT) “Managing for the future: understanding variability and the relative roles of environment, climate, fishing, and trophic dynamics in marine ecosystems” explores these questions using theoretical, empirical, and modelling approaches across a variety of spatial scales and levels of description. Here we review the contributions from these studies and identify remaining challengesThis is a contribution of the CoArc project, which received funding from the Norwegian Foreign Ministry and its Arctic 2030 program. PR acknowledges support from the Research Council of Norway through ‘The Nansen Legacy project’ (RCN no. 276730). MC acknowledges funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No. 817578 (TRIATLAS project) and the Institutional Support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S) to the Institute of Marine Science (ICM-CSIC; Barcelona, Spain)Peer reviewe