Theoretical predictions on the relative importance of consumption (blue dash) and environmental stress (red solid) in structuring communities, with increasing distance along estuarine gradients (standardized to % of estuarine length), translating to increased physiological stress for marine organisms A the Consumer Stress Model (CSM) proposed by Menge and Sutherland (1987) suggests that predation decreases with increasing stress B the Prey Stress Model (recreated from Silliman and He 2018, Menge and Olson 1990) suggests that consumption increases with stress C the proposed Invasion Stress Model (simplified from Rubinoff and Grosholz 2023) suggests that in systems with introduced species, the effect of consumption is extended further along estuarine stress gradients relative to the CSM (panel ‘a’) due to shifts from native to non-native predators, but eventually predation declines D the Salinity Range Model (Attrill 2002) predicts that areas with the greatest range in salinity, mid estuary, would have the least diversity, while the less variable stretches, near the estuary’s mouth and head, would have more consumers.