Fish body mass and assimilation efficiency
We measured fish individual body lengths (cm) and body masses by weighing them on a semi-analytical balance (0.01 g precision). We calculated total community body mass (mg mass CPUE) for each of the 179 communities by summing all individual body masses (Figure S4). The assimilation efficiency, e (the proportion of energy assimilated into fish biomass from total consumed energy), was assigned for each trophic interaction based on consumed resources (Lang et al. 2017). We defined assimilation efficiency as: 0.158 for fish consuming detritus, 0.545 for fish consuming plants and algae, and 0.906 for fish consuming other live fishes or invertebrates (Lang et al. 2017).