Honolua and Mokule'ia bays — about 10 miles north of Lahaina — have been closed to swimmers and snorkelers since Thursday, and the ban was extended to D.T. Fleming Beach Park after the shark sighting by ocean safety officers patrolling the offshore area on personal watercraft.

Maui County supervising ocean safety officer Archie Kalepa said he expected the beaches to remain closed today as a precaution.

He said that in addition to the water patrols, staff from the county and the Department of Land and Natural Resources have been checking the beaches from 7 a.m. to sunset to advise people to stay out of the water.

Kalepa also reported difficulty in posting cardboard shark-sighting signs, which have been repeatedly stolen by souvenir hunters.

"They are important tools that we use to warn people because we can't be at 20 places at the same time," Kalepa said. "It's important for people to respect those signs and not steal them because it could be a matter of life and death."

DLNR enforcement officers believe they have identified the Maui fisherman who left more than 100 dead and dying akule in Honolua Bay sometime Wednesday, but they have not been able to locate him yet.

Randy Awo, Maui branch chief of the state Division of Conservation and Resources Enforcement, said the fisherman has a commercial fishing license and appears to have done nothing illegal, but officials would like to speak with the man about what happened and remind him about responsible fishing methods.

Awo said akule fishermen are exempt from state laws prohibiting fishing within the 45-acre Honolua-Mokule'ia Marine Life Conservation District, where the fish kill was found.

John Naughton of the National Marine Fisheries Service said it is unusual to see predators linger in an area for several days, especially in instances when there are numbers of small dead fish. He also was surprised to hear that tiger sharks were present. "Normally the reef sharks clean them up pretty fast," he said.

Tiger sharks, which are believed to be responsible for most of the Hawai'i shark attacks involving humans, are more likely to scavenge larger carcasses of turtles, dolphins and whales, he said. With a small fish kill, the food would be gone by the time the tigers showed up, Naughton said.

"We recommend that when there are any dead animals of any type in the water, people should stay out of the water for a while to let Mother Nature have a chance to clean things up," he said. "It's going to attract sharks, no question. That's their job."

Sharks normally do not prey on akule, which are fast swimmers that move in dense schools of thousands of individuals.

Akule, or bigeye scad, grow to about 15 inches and a half-pound in size, and are a year-round commercial and recreational catch. They are a popular fish for eating — mostly prepared by frying or by salting and drying.

A commercial marine license is required to take akule using a bag net that surrounds the schools of fish. Fishermen usually take only what they know they can market, releasing the rest or splitting the bag net into a separate enclosure that is left in the ocean for a day or two until the boat returns to retrieve the fresh catch.

State law prohibits fishermen from keeping akule in a bag net in the ocean for more than three days without notifying DLNR.

Maui boater Sid Medeiros said fishermen use akule and 'opelu for bait, and might dump the fish overboard if they spoil, but probably not in the large numbers found at Honolua Bay. He said it's also possible the Honolua fisherman's bag net was attacked by sharks.