Using new DNA barcoding technology, a pair of shark researchers at the University of Hawaii’s Hawaii Institute of Marine Biology determined a tiger shark caused fatal injuries to a 56-year-old Lahaina man bitten Dec. 8 at Maui’s Honolua Bay.
Separately, by measuring bite marks on the surfer’s board, they have determined the shark was approximately 14.3 feet in length.
“Prior to the development of these new techniques, uncertainly over the size and species of sharks responsible for bites to people was common. We are absolutely certain that it was a large tiger shark (in the 98th percentile for size), that bit this man,” lead researcher Carl Meyer, a renowned shark expert, said.
The DLNR Division of Aquatic Resources collaborated with the institute to definitively identify species and to calculate shark size from bite impressions.
Using a “swab kit” developed by the researchers, Adam Wong, a Maui-based DAR education specialist, gathered trace samples of DNA from the bite impression left on the victim’s board. Wong and other DAR staff who respond to shark encounters statewide are provided with swab kits to help further the understanding of the species and sizes of sharks that go after people.
“Once we received the sample from Maui, we used these new techniques to determine the species and size of the shark involved in the recent Honolua incident. These new techniques can be applied in future incidents to help us gain a clearer understanding of these events … which fortunately are quite rare,” Derek Kraft, a University of Hawaii Sea Grant Fellow working at the institute said.
The researchers are confident their method can recover shark DNA from anything that comes in direct contact with a shark, such as a surfboard or stand-up paddle board. They say the method works best if swab samples are taken within hours of an incident, but in this case were still able to recover usable DNA after two and a half days.
All three men said they hope the DNA kits won’t be needed often and they extended their Aloha and sincere condolences to the family and friends of the man killed by a shark ten days ago.