Richard Lam was 11 and attending Punahou School in 1958, the year that upperclassman Billy Weaver, 15, was fatally attacked by a shark off Lanikai. 

 

Lam remembers hearing about the tragedy from one of Weaver’s swim teammates who tried to help Weaver, who was clinging to an air mattress, his leg bitten off at the knee. But with the shark still circling, the boys were not able to get Weaver back to shore, according to reports of the attack.  

 

The fatal shark attack became the catalyst for the isles’ first shark culling, or killings, from April 1, 1959, to March 31, 1960. 

 

"It is time to cull the shark population, especially the tiger sharks, which have no natural enemies," Lam, a Sunset Beach resident and lifelong waterman, said last week. 

 

A recent uptick in shark attacks in the islands has reignited the decades-old debate on how to address the shark attacks, and what might be the root cause: A larger shark population? An increase in green sea turtles attracting the apex predators? Too many two-legged mammals in the ocean? 

 

There is no simple explanation for spikes in shark attacks. And experts say there are no magic solutions on how to prevent them. The suggestions range from doing nothing to doing the extreme — shark culling, which has been deemed culturally and ecologically taboo. 

 

But the notion of shark hunts often floats to the surface when humans are attacked in what seems to be rapid succession. 

 

The latest: A 10-year-old boy was hospitalized Wednesday for a shark bite in waters off Makaha. On Oct. 17, a 44-year-old man was attacked by a 10- to 12-foot shark while swimming from the Mokulua Islands. Eight days before that, a 25-year-old man lost his lower leg to a shark while surfing at Leftovers on the North Shore. About three weeks prior to that, a man was bitten on the leg by a tiger shark while spearfishing off the north shore of Hawaii island. 

 

In all, there have been seven shark-related injuries in waters around the main Hawaiian Islands this year, including one fatal attack off Maui in April. 

 

The attacks have renewed discussion on how to reduce their occurrence. Spurred by Weaver’s fatal attack off Lanikai in 1958, the state tried to allay fears and reduce the risk of shark attacks by implementing shark control programs between 1959 and 1976. In total, 4,668 sharks were killed during six separate programs, according to a review of Hawaii’s shark control programs published in 1994. 

 

Christopher Lowe, a co-author of the study who is now director of Shark Lab at California State University, Long Beach, said he remembers testifying at the Hawaii Legislature in 1998 when the state wanted to pass a measure to fund an intense shark culling program. 

 

"We presented testimony saying that historically (culling) had been done, but there was no evidence it had worked," said Lowe, who earned his doctorate at the University of Hawaii at Manoa. 

 

Carl Meyer, a shark researcher with the Hawaii Institute of Marine Biology, said shark control programs in Hawaii killed thousands of sharks, yet shark bites still occurred both during and immediately after those efforts. For instance, Meyer said, D.R. McGinnis was injured by a shark while diving for lobsters off Barbers Point on Nov. 11, 1969. That case was "particularly demonstrative of the ineffectiveness of culling programs because 33 tiger sharks were removed from waters off Barbers Point alone during the 1967-69 program, yet a shark bite still occurred at the location in November 1969." 

 

Culling has been done off Western Australia and South Africa. Western Australia abandoned its plans last year to cull sharks for a three-year period in response to seven fatal shark attacks from 2010-2013. The government sanctioned culling during a 10-week trial period last year that killed 172 sharks. 

 

Lowe said killing sharks does not reduce the risk of future attacks. "The reality of it is, there is nothing you can do" to prevent shark attacks, he said. "The last thing you want to do is affect the ecology that brings people to the islands." 

 

And that ocean ecology has evolved and is returning to its more natural state as conservation efforts have matured, said George Burgess, director of the Florida Program for Shark Research at the Florida Museum of Natural History. An example is the endangered Hawaiian green sea turtle, whose population has increased by 53 percent over the last 25 years, according to the National Oceanic and Atmospheric Administration. 

 

"If the sea turtle population returns to normalcy, it is going to be highly attractive to animals that eat them," Burgess said. "The chief predators of sea turtles … are sharks. You are going to see more interaction between sharks and turtles in the nearshore." Drawing the sharks closer to shore could lead to more interaction with humans. 

 

Whether that is actually happening is uncertain. Meyer said in an email that "it is possible that turtles are now a more common component of tiger shark diet but we lack contemporary, empirical data needed to draw any firm conclusions." Tiger sharks are "broad generalist predators," he said. 

 

A study of tiger shark diets published in 1995 revealed that turtles occurred in only 15 percent of stomachs of large tiger sharks, Meyer said. But the data for the study were gathered during the shark control programs dating back to the 1960s and 1970s, when the green sea turtle populations were at an all-time low, he added. "We are currently exploring non-lethal imaging methods for assessing turtle occurrence in tiger shark diets," Meyer said. 

 

Small tiger sharks are fish eaters and unable to eat turtles so the status of the rising turtle population would not affect the smaller sharks, Meyer said. Survival of the juvenile tiger sharks is linked to the abundance of fishes and also influenced by the abundance of large tiger sharks, "which have no qualms whatsoever about predating their own species," Meyer said. Thus the tiger shark population is likely to be self-limiting since other sharks are a major component of the diet of large tiger sharks, he explained. 

 

Burgess said the ocean’s return to its natural state is something humans have not encountered for 300 to 500 years. Conflict, which includes human-shark interaction, is inevitable, he said. 

 

Ultimately that will mean "more bites of humans by … sharks," Burgess said. "We’re the ones who are going to have to modify our behavior in some ways." 

 

Marjorie Ziegler, executive director of the Conservation Council of Hawaii, agrees. "Regardless of what data might exist and what they might suggest, what can we do about it?" Ziegler said. "Are we going to cull green sea turtles to try and reduce sharks and shark attacks? I don’t think so, but I have heard people suggesting that too many sea turtles today means too many sharks and shark attacks." 

 

Ziegler, referring to Native Hawaiian mythology, said the ocean is "Kanaloa’s realm. The sea turtles and sharks are part of that realm, humans are not." Kanaloa is the Hawaiian god of the ocean and all its inhabitants. "When we go in the ocean, just as in any wild area, we are at risk from wild animals and the elements. I don’t see this speculation leading to any realistic management plan for turtles and sharks." 

 

Humans are not part of the ocean’s ecosystem, Lowe said. "We take the risk when we go there. Most surfers understand that risk." 

 

All the shark experts point to human population growth and the correlating increase in water recreation as a contributing factor to the human-shark interactions. 

 

"Over time we are also inventing new types of ocean recreation, many of which take us farther offshore into the shark’s natural habitat," Meyer said. "Ongoing increases in the numbers of people using the ocean, and changes in the types of recreational activity they engage in are the most likely explanations for increases in shark bites over time."

 

 

Jan. 27, Lahaina, Maui: Fisherman Michael Pollard, 20, was bitten by a 4-foot reef shark he was trying to throw back at sea. Lacerations to lower left leg. 

 

March 18, Hapuna Beach, Hawaii island: Kansas visitor Dr. Ken Grasing, 58, attacked by an 8- to 10-foot tiger shark. Severe lacerations to left forearm, left hand and thigh. 

 

April 29, Ahihi Bay, Maui: Kihei resident Margaret C. Cruse was fatally attacked while snorkeling. She died after suffering severe lacerations to her right shoulder and underarm and minor lacerations to her right arm and the right side of her face. 

 

Sept. 20, North Kohala, Hawaii island: Off Upolu Point, Braxton Rocha, 27, was bitten on the leg by a 13-foot tiger shark while spearfishing. Lacerations to his left leg. 

 

Oct. 9, Kawailoa ("Leftovers"), Oahu: Colin Cook, 25,was sitting on his surfboard when he was attacked by a 10- to 12-foot tiger shark. Severed his left leg below the knee along with a third of his middle finger on his left hand. 

 

Oct. 17, Lanikai, Oahu: Tony Lee, 44, was attacked by a 10- to 12-foot tiger shark while swimming. Lower leg injuries. 

 

Oct. 28, Makaha, Oahu: Raymond "Ray Ray" Senensi III, 10, was bodyboarding when he was attacked by a 5- to 6-foot gray-and-white shark. Lacerations from his right thigh to ankle.