Understanding and accurately predicting past and future changes

To understand and predict how human activities will affect marine ecosystems in the future, models need to be accurate in detecting and attributing the effects of specific drivers on past ecosystem changes. Previously FishMIP’s primary focus has been on reporting climate change effects on marine fish biomass in the absence of other direct human influences (Lotze et al., 2019; Tittensor et al., 2021; Tittensor et al., 2018; Heneghan et al., 2021). This has been due to the lack of standardized historical fishing effort data at the global scale, meaning that fishing has been incorporated in only a small subset of the global models, in a variety of ways. To systematically tease apart the relative and combined effects of global climate change and fishing, and the extent to which future fisheries are at risk under different management scenarios (Tittensor et al., 2021; Scherrer et al., 2020), a consistent approach for incorporating fishing drivers is needed. This is especially important for the development of scenarios describing how evolving socioeconomic and environmental conditions are likely to affect future fishing fleets, from artisanal to industrial scales, and to provide knowledge on the potential cumulative and interactive impacts of fishing and climate pressures on marine ecosystems (see Chapter C. 2).