Results from DNA testing of a wetsuit worn by a teenage boy bit by a shark last month while lobster diving in Encinitas confirmed the attack was made by a great white shark, officials said Oct. 10.
Lifeguards and scientists had thought from the start they probably were dealing with a white shark, which witnesses described as being about 11 feet long.
But it wasn’t until forensic analysis of DNA swabbed from the wetsuit of 13-year-old Keane Webre-Hayes came back Friday, Oct. 5, that officials had conclusive evidence that a white shark was involved in the attack.
Officials say identifying the species of shark involved and providing information about white shark movements and behavior could help lifeguards prevent attacks from happening in the future.
“Shark bite incidents are exceedingly rare considering the number of people that use Southern California waters, but people do need to be aware that the fall season is a time when more large juvenile and adult sharks may be moving along the coast,” Chris Lowe, director of Long Beach State University's Shark Lab, said in a statement.
Lowe is conducting field research in Baja California this week, and couldn’t be reached for comment.
Keane Webre-Hayes was critically injured in the attack, which occurred as he was diving for lobsters at Beacon’s Beach at the foot of Leucadia Boulevard on Sept. 29, the first day of the recreational lobster season.
The boy was about 200 yards from shore, in water about 9 feet deep, when he was attacked. Lifeguards later said the boy was lucky that an off-duty state lifeguard and off-duty Oceanside police officer were nearby. They pulled the badly bleeding boy into a kayak and applied pressure to his wound.
He was airlifted to Rady Children’s Hospital in critical condition and underwent surgery.
He has since been released from the hospital and is now at home recovering, according to Encinitas city officials.
The lab test used to confirm the presence of white shark DNA is similar to a new procedure being developed that can detect white shark environmental DNA in ocean water samples. Environmental DNA or eDNA can be found in cellular materials left behind by sharks and other animals.
Researchers hope to develop a species-specific test that could be used by lifeguards to detect what type of sharks have been in an area based on water sample testing.
That, along with current monitoring efforts such as aerial surveillance and tracking tagged sharks, would help give lifeguards and biologists a better idea what sharks are in the area.
“While the methods still will require more testing and calibration, this could potentially offer a way for lifeguards and biologists to figure out what species was involved, and whether that species is still in the area,” Lowe said.
--- Karen Kucher is a reporter for The San Diego Union-Tribune.