Their most important finding was that species richness -- the number of different species represented in the study regions -- has increased over the study period, driven by the northward migration of apex predators such as whales, sharks and seabirds. Mesopredators such as fish and crabs exhibited a relatively limited degree of northward migration, confined to the shallow continental shelf seas of the Pacific and Atlantic. Although the spatial extent varies, this northward expansion was driven by changes in either climate, productivity, or both.These climate-driven biodiversity changes, in turn, led to alterations in potential species associations due to habitat overlap between taxa from different marine communities during unprecedented periods of temperature and sea ice changes.