The brothers, longtime sport fishermen who live in Massachusetts, released a juvenile tiger shark in late July after catching it from a beach. “Immediately I started yelling to my brother, ‘It’s a tiger, it’s a tiger shark!’ The adults are also more dangerous to humans than most shark species, though unprovoked fatal bites are rare. Young tiger sharks are historically less common than adults in northern waters, which makes the brothers’ discovery even more surprising, Chisholm said. For the Rouette brothers, the encounter with a tiger shark provided a thrill they won’t forget.