Fitness Files: Shark behavior up close and too personal

Anybody see the recent news coverage of the shark breaching in Sunset Beach, in Huntington Beach? My son, Ben Slayback, was one of the surfers interviewed.

As his friend Drew Palumbo aimed his GoPro at Ben catching a wave, a shark caught Drew’s eye and he got the rare footage.

Maybe you heard Ben tell the reporter, “I thought it was time to get out to the water.” However, only his mother noticed that he described a second shark cruising around his surfboard.

“You didn’t get out fast enough,” I thought, “if you stayed to have another shark encounter.”

The dailymail.com quoted Chris Lowe of the Cal State University Long Beach Shark Lab, as saying the shark was probably a 6.5-foot juvenile, here for the warm El Niño waters. Apparently a lot of shark sightings have been reported this year as the predators feed on plentiful fish, perhaps halibut and stingrays.

Lowe estimates that the local sharks are about a year old, not yet dangerous to people, although some surfers reported being bumped. Frequent shark sightings, from San Clemente to Seal Beach, have resulted in a few beach closures.

In a March 21 article in the Orange County Register, Lowe postulates that the breaching behavior might be caused by parasites, small water bugs called copepods, which cling to sharks. By going airborne and slamming back into the water, sharks shake off their irritating travelers.

“Maybe it’s play” or just excitement, Lowe said. “We just don’t know.”

On vacation last week, I spent a fascinating six hours at the Monterey Bay Aquarium. When I heard that a shark lecture was scheduled, I hunted down the presenter. Steve Johnston, a handsome guy with shiny white ringlets, a neatly trimmed beard and a khaki shirt worthy of a forest ranger, told me he’d seen the video, with that unmistakable shark silhouette against the horizon.

“Breaching is common behavior in Cape Town, South Africa,” Johnston said.

In a deep, dark undersea “cavern,” beneath a land outcropping, sharks hide, watching for seals above. The skulking sharks shoot up to crunch a seal. This hunting behavior propels sharks with such force that they fly out of the water. At shark feeding time, Cape Town fishing boats clear out, dodging huge sharks that blast out of the water alongside the boats.

I got some insight into the biology of the flying sharks from Janet J. Lee’s NationalGeograpic.com article, in which she relays information from John Carlson, research biologist from the National Marine Fisheries Service in Florida.

“When sharks in the lamnid group — which includes great whites, mako, and salmon sharks — do spot prey at the water’s surface, they’re uniquely built to go after them,” she wrote.

Lamnid sharks have capillary networks (tiny blood vessels) warming their muscles over ambient seawater temperature. This together with powerful streamlined tails enables them to leap.

Johnston said that to his knowledge, the breaching behavior was documented only once before on the California coast.

“Juvenile sharks don’t know they’re sharks yet,” he said, adding that until they’re 8 to 10 years old, their “baby teeth” can’t consume seals, so they hunt fish like herring and mackerel.

“That breaching shark may have been a juvenile, but wherever there are seals and sea lions, there are great white sharks.”

Anyone cruising through the turning basin in Newport has spotted the buoy where fat sea lions loll on top of one another.

Johnston ended our interview by adding — ominously — that “great whites hunt in warm waters” also. On the other hand, he’d told me earlier that adult sharks of many species don’t feed where they give birth, a smart survival adaptation.

As much as I want to believe Lowe’s team of shark experts, who, by the way, have been tagging juvenile sharks for eight years, I’m not the only one who said that shark in Sunset Beach looked big.

It must have looked enormous to a newswoman who introduced video this way: “That’s not a whale, folks.”

At dinner last night, Ben said, “No reference point, so no way to know how big the shark was, but it had a wide girth. That day, two surf fishermen we see there all the time waved like mad to get us out of the water. They said that thing was 10 feet long.”