Great White Lands in a Lagoon

Back and forth, back and forth: It was almost as if the great white shark was pacing, swimming the same small circle over and over.

“Territorial loops,” said Matt Lundberg, a fisherman who has cashed in as an aquatic tour guide since the 14-foot creature showed up in shallow water almost a week ago.

The 1,700-pound female -- identifiable by her gender-specific dorsal fin -- swam into an estuary off Naushon Island, about three miles from this Cape Cod village. Scientists believe she drifted too close to shore and became stuck in the 20-foot-deep lagoon.

The area is rich in striped bass, bluefish and other sea life to keep the shark well fed. But marine scientists suspect she is disoriented and unable to return to the open ocean. She appears to be healthy.

Soon after the shark was sighted, a state biologist used a pole to insert a device in her fin. The mechanism will provide information until April, when it will pop up and beam its location to marine scientists.

Dan McKiernan, deputy director of the state division of marine fisheries, said Monday that the instrument was programmed to release itself from the shark at the end of its operational existence. McKiernan said it would help track the shark’s travels.

High tides associated with the full moon today could allow the shark to escape from the lagoon, McKiernan said. A tropical storm expected to hit the region today also could raise the water levels.

“In the past few years, there have been occasional sightings in the Gulf of Maine,” he said, “but it is very uncommon to see a great white shark in this region.”

McKiernan said marine biologists were keeping a careful watch on the shark. “Our approach is to do things that are not invasive in terms of the animal’s behavior,” he said.

The appearance of a great white so close to shore is rare enough that state wildlife officials hastily passed a regulation late last week to protect the animal. The rule makes it illegal to harass or harvest the shark in state waters, which extend three miles from the seacoast.

But the ordinance did little to dissuade eager sightseers, who packed boats like Lundberg’s in hopes of catching a glimpse. Lundberg, 20, charged $100 per boatload for the 45-minute crossings to and from Naushon Island.

His launch holds a maximum of six passengers, and many people waited three hours or more for a spot on board. Some brought small children and even small pets -- oblivious to any risk from venturing near the carnivorous shark.

From 8 a.m. until sundown, Lundberg spent the weekend taking visitors to within five yards of the shark. A small sandbar separated boats from the lagoon, where the shark circled relentlessly.

Allyssa Lungarini, a 29-year-old nurse from Sandwich, on Cape Cod, said she did not mind the wait. “I’m a shark freak,” she said. “I have a wall full of collections -- anything with a shark on it, I collect.... This is a once-in-a-lifetime chance. I don’t mind waiting three hours. I’ll wait all day if I have to.”

Lungarini said that she was born in 1975, the year “Jaws” was released. The movie, which depicted a fictional frenzy caused by the appearance of a ravenous great white shark, was filmed on Martha’s Vineyard, not far from Naushon Island.

The island is privately owned by the Forbes family, of which Democratic presidential candidate John F. Kerry is a member. The land is held in trust, and family members are permitted to visit. A portion of the island is also owned by descendants of Ralph Waldo Emerson. A small section of beach on the island is accessible to the public.

David Peter, an engineer from Foxborough, took his boat close to Naushon Island on Sunday and found the area uncharacteristically crowded. Peter, 46, said there were 30 to 50 boats in a stretch of water where he might normally see one boat. He tried to bring his boat close to the shark but found the water too shallow and the area too rocky.

But Gerry McDade, a builder from Newton, lucked out when a pair of fishermen offered to ferry him and his 11-year-old son out to see the shark. McDade whipped out his video camera and held an impromptu screening on a pier.

“You can see it under the water. It’s a big black thing -- and then all of a sudden it comes up,” said McDade, 46.

Taylor McDade piped in: “It was big and huge, and it swims really fast. It just goes around and around in circles.”

There has not been a fatal attack by a great white shark in Massachusetts since 1936, when a 16-year-old boy was killed. State historical records also describe a fatal attack by a great white in 1670.