Why they bite

KAILUA-KONA — A rising tide of shark bites off the Maui coast over the previous two decades appeared to indicate that sharks in the area had acquired a disturbing affinity for the taste of human flesh.

“Over the past 20 years, Maui has had almost double the number of shark bites than any other island,” said Carl Meyer, principal investigator at the Hawaii Institute of Marine Biology.

Between 2012 and 2014, a total of 19 shark bites occurred, including eight bites in 2013 alone. Before 2012, there had never been more than three documented shark bites in one year stretching all the way back to 1980.

Concern and questions over the troubling trend was great enough that the Department of Land and Natural Resources commissioned a study.

“There was concern at the time that sharks were behaving differently on Maui,” said Bruce Anderson, administrator of the DLNR Division of Aquatic Resources. “We really had very little information at the time on why sharks were behaving the way they were, and really how they are behaving at all in this area.”

The Department of Health contributed roughly $186,000 to the study, Anderson said. The Pacific Islands Ocean Observing System, Ocean Tracking Network and Wildlife Computers also provided funding support.

Utilizing satellite tracking and acoustic tracking technology, Meyer and his team kept tabs for up to two years on 41 tiger sharks they tagged and captured around Maui and Oahu.

The research showed the sharks favor waters between Maui, Lanai, Molokai and Kahoolawe islands. The area is rich with coral reefs that offer habitat for fish and other marine life that sharks like to eat.

Together, Maui and nearby islands have more preferred shark habitat than all the other main Hawaiian Islands combined, Meyer said.

Maui sharks tend to stay in these waters. But the area also draws sharks that normally live in Oahu waters, particularly during mating season.

The study also looked at frequency of tiger shark visits to certain recreational ocean sites off Maui and Oahu. The tracking showed individual shark visits occurred at these sites an average of once every two weeks, and sharks lingered in the areas for roughly 12 minutes.

Data on some sites in Southwest Maui, such as Kalama and Makena Point, the presence of tiger sharks was detected on up to 80 percent of days monitored. Still, Meyer said that considering the thousands of daily swimmers, shark bites “remain rare events.”

He added that the pattern of bites on Maui, 70 percent of which occurred between 9 a.m. and 4 p.m., is driven more by human behavior than the other way around — in other words, being in the water when sharks are present.

Anderson said shark behavior hasn’t changed, but people’s behavior has, as more people are kayaking, swimming, spearfishing and taking up ocean sports such as stand-up paddleboarding.

Anderson said the state would increase its educational outreach in response to the study.

He urged people to stay out of the ocean if the water is murky. He recommended avoiding areas near streams where dead animals may wash out, attracting sharks. He suggested swimming in groups, as a buddy can help if a shark does bite.

“One other thing I want to stress is swimming in the ocean is swimming in what amounts to a wilderness type environment,” Anderson said. “Sharks are part of this environment, and we have to accept that they are there and take precautions to avoid encounters, which are going to occur from time to time. … That is a fact of life that is not going to change.”

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The Associated Press contributed to this report.