Role of trophic models and indicators in current marine fisheries management

The previous decade has witnessed a flourishing of studies on how fisheries and marine food webs interact, and how trophic models and indicators can be used for assessment and management purposes. Acknowledging the importance of complex interactions among species, fishermen and the environment has led to a shift from single species to an ecosystem-wide approach in the science supporting fisheries management (e.g. Johannesburg Declaration, Magnuson-Stevens Act). Moreover, fisheries managers today acknowledge that fishing activities are linked to a range of societal benefits and services, and their work is necessarily a multi-objective practice (i.e. ecosystem-based management). We argue that the knowledge accumulated thus far points to tropho-dynamic models and indicators as key tools for such multi-dimensional assessments. Nevertheless, trophodynamic approaches are still underutilised in fisheries management. More specifically, most management decisions continue to rely on single species and sector-specific models. Here we review examples of applications of trophodynamic indicators within fisheries assessments in well-studied ecosystems, and discuss progress made (as well as lack thereof) towards increased integration of these metrics into marine resource management. Having clarified how trophic indicators fit within current policy and management contexts, we propose ways forward to increase their use in view of future management challenges.