Oceans without sharks would be far less healthy – new research
Gray reef sharks and blacktip reef sharks near Tahiti, French Polynesia. Alexis Rosenfeld/Getty Images Michael Heithaus, Florida International University There are more than 500 species of sharks in the world’s oceans, from the 7-inch dwarf lantern shark to whale sharks that can grow to over 35 feet long. They’re found from polar waters