Scientists in South America are studying the shark species thought to be responsible for a spike in deadly attacks since 1990. Marine biologist Danni Washington and shark conservationist Paul de Gelder join a team tracking tiger sharks off a pristine tropical archipelago in Brazil.  

A 14-foot giant mako shark is spotted in the waters of Portugal's Azores region. Underwater cinematographer Joe Romeiro and his marine biologist wife, Lauren, search the teeming depths around the ancient islands to capture the beast on film.