Mysterious Cape Cod dolphin beachings continue

More than 100 dolphins have stranded themselves along Cape Cod's 25-mile coastline in the last three weeks, and the number is growing.

Rescuers there say it's just about the worst they've ever seen. And scientists are still looking for answers.

The alarming number of dolphins beaching themselves along the 25-mile Cape Cod coastline was baffling scientists for a third week.

On Monday, they responded to a call that three dolphins were approaching shore. Two swam away unharmed, but one got too close to the beach and needed intervention by rescuers from the International Fund for Animal Welfare.

The animal later died and, along with three more carcasses discovered over the weekend, the number of dolphin beachings swelled to 102, nearly the normal amount for an entire year.

Katie Moore, manager of the Marine Mammal Rescue Team, says she simply doesn't know why this is happening.

Marine biologist Misty Niemeyer has been examining the bodies of dolphins that did not survive, looking for clues. "One thing it might tell us," she explains, "is, if all of these animals do look healthy, than we know that they were a healthy group of dolphins and that it was more likely something geographic or weather-related, something like that -- not an emerging disease or toxins or anything like that."

Two dozen of those stranded dolphins were saved and safely released back into the ocean, with electronic tags enabling scientists to track their movements.

While many of the dolphins have traveled far away from Cape Cod, the already overworked rescue crews continue to monitor dozens of dolphins that remain offshore in Cape Cod Bay.

Is this the most intense two-week period of Niemeyer's career?

"It's been about the most intense," she responded. "We've had a few strandings like this in the past, but these last few weeks have definitely been pretty intense as far as the numbers of animals that have been coming in in a short period of time (is concerned)."

Scientists are scheduled to brief Congress on the situation later this week.

To see Jim Axelrod's report, click on the video in the player above.

  • Jim Axelrod

    Jim Axelrod is the senior national correspondent for CBS News, reporting for "CBS This Morning," the "CBS Evening News," "CBS Sunday Morning," and other CBS News broadcasts.