Energyscapes pinpoint marine megafauna feeding hotspots in the Mediterranean

Abstract

Ocean giants shape the structure and functioning of marine food webs via trophic top–down controls, landscapes of fear, vertical and horizontal redistribution of nutrients, energy, and matter. Yet, they face threats from overfishing, pollution, habitat degradation, and climate change, and one-third of marine megafauna species are at risk of extinction, ultimately endangering the resilience of entire ecosystems. In such a context, knowing when and where megafauna find resources to balance their substantial energy requirements is critical for their management. Through an energyscape approach integrating abundance censuses, diet, and energy requirements, we investigated the prey consumption patterns of Mediterranean marine megafauna during the summer. We thereby shed light on a diverse guild of species composed of fishes, mammals, reptiles, and birds and estimated that 4.1 million individuals consume 1.6 million tons of prey each summer, pelagic cephalopods being the primary food resource and cetaceans and tunas being key players in the community. Spatial patterns in prey consumption reflected the diverse distribution and needs of the megafauna species and underlined the critical importance of the western Mediterranean for the megafauna community. Conservation strategies should prioritize spatial and biological diversity to safeguard megafauna and ecosystem functions across the Mediterranean basin.