In Fijian mythology, Dakuwaqa is a shark-god. He was greatly respected by fishermen because he protected them from any danger at sea and sometimes protected them from evil denizens of the sea.
He was once going inland to conquer Kadavu Island through the river when another god challenged him in the form of an octopus. After a great battle, the octopus won forcing Dakuwaqa to promise to never attack Kadavu again.
That is how Dakuwaqa became the god and protector of Kadavu.