Gradients in marine biodiversity

Abstract

Marine Biodiversity Marine animal biodiversity increases severalfold toward the tropics, but a general theory to explain this is lacking. Edgar et al. used extensive global surveys to address this question for fish and mobile invertebrates on rocky reefs over 100° of latitude. Regional diversity was highest near the equator, but local diversity reflected abundances that differed between fish, which peaked in the tropics, and invertebrates, which peaked at higher latitudes. These patterns correlated with temperature gradients for fish and nutrients for invertebrates. Thus, fish appear to have limited the local abundance and diversity of invertebrates in the tropics. Regionally, however, diversity depended strongly on the area of suitable reef habitat, raising alarm about the loss of biodiversity as tropical reefs decline. Sci. Adv. 10.1126/sciadv.1700419 (2017).