Ocean warming has been implicated in the observed decline of oceanic phytoplankton biomass. Some studies suggest a physical pathway of warming via stratification and nutrient flux, and others a biological effect on plankton metabolic rates; yet the relative strength and possible interaction of these mechanisms remains unknown. Here, we implement projections from a global circulation model in a mesocosm experiment to examine both mechanisms in a multi-trophic plankton community.
Large reductions in the abundance of exploited land predators have led to significant range contractions for those species. This paper shows similar responses in highly mobile tuna and billfish. It implies ecological extirpation of heavily exploited species across parts of their range.