Measuring resilience in aquatic trophic networks from supply–demand-of-energy relationships

The supply–demand curve is used to analyse the exchange of energy in food webs and measure its resilience. The slope of a supply–demand curve is an estimator of the redundancy of internal flows, which represents the energy in the reserve of the ecosystem, a concept defined as resilience. We found that resilience can vary according to the stress level to which the ecosystem is subjected. As an example, the pattern of variation of resilience due to the historical effect of climate change (almost six decades of a sustained perturbation of temperature increase) in the southern Gulf of Mexico indicates a significant decreasing trend of the resilience, which also represents a loss of vulnerability, suggesting that this measure of resilience could be of interest for the management of living resources. In a global sense, we also found a relationship suggesting that resilience tends to increase with latitude.