MIAMI — When a major hurricane, extreme heat or other climate threat devastates an ocean’s lifeblood, its recovery could be aided by the presence of sharks. Sharks as oceanic medics? That’s the idea behind a study on sharks and their role in the ocean. The study, led by researchers at Florida International University, was published this week in the Journal of Animal Ecology. Decimate sharks and you’ve made oceans less resilient to extreme climate events, said the FIU scientists.