LAMEQUE, N.B. -- Six stranded dolphins are stubbornly refusing to be guided out of shallow waters in northern New Brunswick, rescuers said Thursday.

"The dolphins are doing what they want to do," said Tonya Wimmer, director of the Marine Animal Response Society. "We're going to regroup and figure out what to do about our little unco-operative dolphin friends."

It's been more than a week since seven dolphins became stranded near Lameque, with one dying two days later. To get back to open ocean, they would have to swim through an area that's only about a metre deep at high tide, and dolphins don't like shallow water.

Three boats have made multiple attempts to herd the dolphins, including at high tide Thursday morning, but they always turn back before crossing out of the shallow water.

"At this point we're basically using all the tools in our toolbox that we can think of. Whether it's herding, or trying to scare them out, trying to attract them out," said Wimmer.

On Thursday, as more than a dozen people watched from shore, officials from the marine society as well as the Department of Fisheries and Oceans deployed an acoustic pinger in a bid to push the dolphins along.

"We could definitely tell that we were disturbing them, which is part of the process," said Andrew Reid of the society. "They were evading us. Swimming quite rapidly, swimming under the boat. So they definitely were being annoyed."

The rescuers said the biggest obstacle is the strong current, which gets stronger as the tide goes out. The boats have to be careful not to smash into a bridge, or hit the animals.

Wimmer said the animals look in "fairly good health," and they have some fish and layers of blubber to draw on. But rescuers don't think the dolphins will leave on their own, because of the nature of the waterway.

"We just mostly want to make sure that, as long as they're not being disturbed too much, and they stay healthy, we can keep an eye on them. But they're hitting a bit of a level where people are very concerned and there's interest to want to do something, so we at least have to see what we can do," she said.

Reid said the dolphins are very social, and may have ended up in the shallows because one of them -- possibly their leader -- was sick. Or perhaps they were simply chasing food, he said.

"They're probably fine for a while. The white-sided dolphins are actually a more northern species, so they're use to being in fairly cold water. Obviously if there was ice and it was below freezing there would be more concern," Wimmer said.

Atlantic white-sided dolphins are common in Atlantic Canada.

They can reach 10 feet in length and 500 pounds.