A University of Hawai'i study suggests that shark-diving tours off O'ahu have not resulted in more danger to humans.

The report also suggests that the two shark tours that operate along O'ahu's North Shore are not causing harm to shark habitat.

The study's authors reviewed tour boat logbooks and tested boat captains on identifying sharks that congregate around the cages that hold tourists who pay to see the animals up close.

They concluded that while some shark species appear to be growing in numbers and others are declining, the tours were causing no change in the overall shark population.

They also determined that the type of sharks attracted to the cages rarely bite people.

The study was published in the journal Environmental Conservation.