Up to a third of all shark species face some threat of extinction, according to the International Union for Conservation of Nature.
They are slaughtered around the world for their fins, which are prized in Chinese culture and used to make soup.
Sharks are often caught, their fins sawed off and then discarded still alive only to tumble uncontrollably in the water until they die.
The new refuges established this month are in addition to several others that have recently begun to provide protection for sharks.
Venezuela and the European Union have banned the practice of cutting off shark fins and discarding the body at sea in their territorial waters.