Modeling northeast Atlantic marine food webs under global change scenarios.

Climate change and commercial fishing are prominent contributors to global change and can cause gradients in numerous biotic and abiotic variables, all of which can alter food web dynamics. This study aimed to predict future northeast Atlantic marine food webs based on allometric foraging behaviour. More than one thousand food webs from 1992 to 2016 spanning 2035 km² were modelled and calibrated based on a novel empirical dietary database containing >400,000 individual predator stomachs. A suite of flow and structural ecological metrics, such as connectance, mean trophic level, redundancy, and total energy flux, were calculated from the food web models, which due to their systemic nature can be used to infer ecological resilience of northeast Atlantic ecosystems. The relationship between the suite of ecological metrics, sea surface temperature and mean yearly fishing effort were tested using Bayesian Additive Regression Tree Models. Spatial and temporal variation was found in both structural and flow-based metrics providing evidence that climate change and commercial fishing are potential drivers of northeast Atlantic food web dynamics and in turn ecosystem resilience. For example, redundancy in trophic interactions, which provides buffering capacity to ecosystems in the face of stress, was found to increase with sea surface temperature. A primary goal is to provide robust understanding of food web structure and ecological resilience across multiple scales, helping to highlight vulnerable systems, communities, and species across the northeast Atlantic. This project has the potential to provide the scientific advice needed for climate change and sustainable fisheries management to be effective despite the uncertainty of global change.