Marine experts continue to be baffled by a rash of dolphin strandings on the beaches of Cape Cod, Massachusetts, where 179 short-beaked common dolphins have been beached since January 12—almost five times the average number of dolphins that have been stranded annually over the past 12 years. One hundred twenty-four of them have died. Workers from the International Fund for Animal Welfare, an organization that rescues animals, protects animal populations and preserves habitats, have led the rescue efforts. According to an Associated Press story on February 16,
…necropsies have been done on dead dolphins, and a Congressional briefing was held early this month in the push for answers. But researchers can offer only theories about things such as changes in weather, water temperature or behavior of the dolphins’ prey.
Dolphins and other marine mammals have been found stranded on Cape Cod beaches for centuries; an average of 228 dolphins, whales, porpoises, seals and other sea mammals are beached here during a normal year. But experts are mystified by the sheer numbers in a single month, and also by the unusual fact that they are of one species. As Jenny Marder reported on the PBS NewsHour blog The Rundown:
“All  are common dolphins,” said Katie Moore, manager of the marine mammal rescue effort for the International Fund for Animal Welfare, the group leading the effort. “Which is what’s scary. If I look over the last 13 years, the average number of common dolphins we see [stranded] in a year is 38. This is an enormous event.”
Dolphins are social, tending to travel in large groups, which helps them forage and fend off predators—but which also can leave them stranded in large numbers. Moreover, the Cape is shaped like a craggy hook, which tends to channel the animals inland, where they can remain trapped and beached during low tide.
Still, experts have no explanation for the unusually high numbers of stranded animals. “There are no indications that tidal patterns have changed and no signs of disease in the 10 dolphins that have undergone detailed necropsies,” according to the PBS blog.
Reporter Jay Lindsay of the Associated Press hung out with the dedicated dolphin rescuers as they attempted to herd the wild mammals back into deep waters:
One drifts off to the left, where he could beach again. The manager of the stranding team, Katie Moore, slides over, grabs its dorsal fin, and gives it a push in the right direction.
“You’re going the wrong way, buddy,” she says.
The inlet continues to fill and the dolphins break into waters that are deeper than the rescuers can follow, but they’re in two groups. The IFAW’s boat eventually follows one pod and the Wellfleet harbormaster takes another. The noise from the motors pushes the dolphins ahead. So do acoustic pingers, devices that make a sound that annoys the dolphins.
Moore, visibly exhausted from the ongoing rescue efforts, later told Lindsay, “We just don’t know when it’s going to end anymore. That wears on people.” But she has been inspired by IFAW’s success in returning the dolphins to the sea. “I think that as humans we have such a huge impact on the ocean environment, and on these animals in other ways, that this is our opportunity to do the right thing.”Video is by the International Fund for Animal Welfare and is embedded from YouTube.com.