Mass stranding of bottlenose dolphins off Cape Cod said to be largest in Massachusetts history

Rescuers were working to save around 18 bottlenose dolphins that got stranded off the coast of Cape Cod early Tuesday morning. 

On Monday morning, around 30 dolphins had become stranded, making it the largest known stranding of bottlenose dolphins off Massachusetts, according to the International Fund for Animal Welfare (IFAW). The IFAW said that mass strandings can sometimes repeat in the following days. 

The 30 dolphins had originally become stranded between First Light and Ellis Landing in Brewster at about 5:30 a.m. Monday, when they came in with the tide. A woman noticed the animals and reported it. The IFAW quickly responded to the area, but five to six of the marine mammals died before help arrived. 

The IFAW worked throughout the day on Monday to get the mammals away from the shoreline before the next low tide at 5:13 p.m. They said late Monday afternoon that they were still successfully being steered away. 

However, on Tuesday morning, around 18 dolphins had become stranded again between Brewster and Wellfleet. The animals were in "decent condition" and had begun to refloat while the tide rose. 

"This is a very stressful event. Partially because it's just really complex to have multiple sites where these animals are, and the fact that they're so big makes it much harder for our team to do a good job of taking care of them," said Dr. Sarah Sharp with the IFAW in a statement. 

The IFAW said it continued to monitor the mammals and coax them out of Wellfleet Bay to "give them the best chance of survival." 

The IFAW said they had tagged two of the mammals to track their movements and later in the day saw them rejoin the larger pod of about 22 dolphins, about half a mile off the Brewster and Orleans area. 

"So, now they're in a better place. If they stay where they are, they'll be safe through the tide," Dr. Sharp said.

The next low tide is at 6:10 p.m. Tuesday. 

The organization said it had seen an uptick in bottlenose dolphins becoming stranded off Cape Cod in the last few years. 

"Bottlenose dolphins are typically an offshore species," the spokesperson said. 

The IFAW said that Cape Cod causes many navigational issues for the animal, compounded by the fact that there is a lot of bait fish in the area, local fishermen told them. 

"The curve of the Cape, the hook shape and Wellfleet in particular, is another hook within the Cape," Dr. Sharp explained. "In addition to really big tide fluctuations right now. It's about a 13-foot vertical change right now. We've got really low lows and pretty high highs. So that allows animals to get into places that they then can't get out of once the tide drops."

They asked that anyone who encounters a stranded or distressed marine mammal not get close and never drag or push the animal back into the water. 

"Similar to a person involved in a car accident, dolphins can become injured and exhausted during a stranding event," the IFAW said.

Instead, they recommend calling their IFAW stranding hotline at 508-743-9548.