Get out of water if dolphins are jumpy, shark experts say
| • | Illustration: Sharks compared: The great white and the tiger shark |
By Jan TenBruggencate
Advertiser Science Writer
A shark attack on a man swimming off Makua Tuesday occurred among a pod of spinner dolphins, which have been preyed upon by great white sharks in recent years.
Eugene Tanner • The Honolulu Advertiser
And although scientists have been unable to determine whether the large shark that bit Manoa resident John Marrack was a great white or a tiger shark, the attack raises one clear caution:
John Marrack of Manoa, who was bitten by a shark, points out the area on his foot with the most stitches.
"If the dolphins change their behavior or disappear, get out of the water," said zoologist and shark researcher Gerald Carr, acting curator of Waikiki Aquarium.
National Marine Fisheries Service researcher John Naughton had the same advice: "Certainly if you see the animals acting erratically, stay away from them."
University of Hawai'i shark researcher Kim Holland said that shark attacks are such rare events that it is difficult to make conclusions about them or to develop recommendations about how to behave in the water.
"There's no reason to believe that this is anything but one of those uncommon cases when a shark takes a bite out of a human and then goes away. There's no way of knowing why these very rare events occur," Holland said.
Makua shark victim Marrack said the spinner dolphins he was swimming with "took off like rockets."
Moments later, he saw a giant silvery beast beneath him and felt something grab his foot. The bite fractured a bone in his leg and ripped his skin. He was rescued by a passing boater.
Marrack said an orthopedic surgeon told him yesterday that he may have sustained fractures to his right foot, "but it's nothing that can't heal itself."
"He said I'm so lucky because when a shark would bite, it would crush and rip, but it just bit and released," Marrack said, sitting in his front yard with his bandaged foot propped on a bench.
"Apparently, there's no ligament or tendon damage and that's the main thing, so there's a good chance it could be a 100 percent (recovery), other than scarring," said Marrack, who celebrated his 61st birthday yesterday.
Marrack, a retired CPA, said he received "dozens and dozens" of stitches. He was told it may take about four weeks before he can resume normal activities.
Marrack said that he and his wife have gone on similar dolphin excursions dozens of times before, and he said he probably would go again.
"I see myself doing it, but we'll have to see," he said with a laugh. "The odds of getting bit by a shark in Hawai'i in the first place are so astronomical."
Carr said he has had shark encounters while swimming in the lagoon at Midway in the Northwestern Hawaiian Islands. When dolphins became agitated or left the area, a Galapagos shark or other shark species was almost surely in the vicinity. His orders to fellow swimmers were to immediately get out of the water.
"I would tell them, 'The landlord is here,' " he said.
The largest sharks in near-shore Hawaiian waters tend to be either tigers or great whites. Tigers are more common. Both are animals that travel a great deal.
Holland's research shows that tiger sharks, although they may return to the same coastlines occasionally, are constantly on the move and often swim long distances.
Tagging results show that great whites, too, are long-distance swimmers. One was recorded crossing from the California seal rookeries to the waters off Kaho'olawe and back. Great whites are uncommon in the Islands, but not as rare as they were once believed to be.
The great mystery for researchers is where the massive meat hunters find their meals.
Satellite tag results show that the California-Kaho'olawe shark spent a lot of time in very deep water.
"If they are staying at depth, what down there are they feeding on? Tuna? Squid? We don't have good stomach-contents data to know," Carr said.
Naughton said great whites have been seen eating spinner dolphins along the Wai'anae coast. Tiger sharks are probably not fast enough to catch a swimming dolphin, but a great white is, he said.
Carr said "they do swim at a pretty good pace," but he believed that a dolphin would have to be sick or injured for a great white to catch it.
Others have suggested that the increasing number of Hawaiian monk seals in the Islands, particularly around Kaua'i and Ni'ihau, could provide a food source. Several great white shark sightings in recent years have been around Ni'ihau.
Scientists recommend being alert in the water, but they don't see the need for severe restrictions on ocean activities.
"We certainly don't want to issue a recommendation to halt these excursions (with dolphins). This is a nice clean eco-friendly excursion, but people need to be aware of this," Naughton said.
Advertiser staff writers Zenaida Serrano Espanol and Will Hoover contributed to this report.
