Editor’s note: This article was updated at 5:55 p.m. with more details provided by IFAW.
At least 10 Atlantic white-sided dolphins died off the Cape Friday after 125 dolphins were stranded during low tide in what the International Fund for Animal Welfare is calling the biggest “single mass stranding event” in its response history in the past 25 years.
“There is no set reason for why these dolphins strand,” Stacey Hedman, director of communications for the IFAW, explained in an email Friday afternoon. “Cape Cod is a global stranding hotspot due to the curvature of our shores and the fluctuation of our tides.”
The dolphins got stuck at “The Gut,” an area near Great Island and Herring River in Wellfleet. This area is tucked along the west side of Wellfeet on the Cape Cod Bay side.
This section of the Wellfleet Harbor area, according to Misty Niemeyer, the IFAW stranding coordinator, is a “historical trap” for dolphins.
IFAW was initially in the area helping one stranded Atlantic white-sided dolphin that was found off the shores of Eastham at about 5:30 a.m. Friday, Niemeyer said. That dolphin was moved to deeper waters in Herring Cove, Provincetown.
As the IFAW team was gathering gear from the trip, it received a new report of 10 dolphins in Wellfleet, she said. As they made their way to Wellfleet, the number of dolphins increased and they found 80 to 100 stranded dolphins.
The Wellfleet area features “dangerous mud,” and low tide was at 11:23 a.m., Hedman said, when first announcing the stranding at about noon. The first crews to arrive were able to walk out in the mud to help, she said, but 10 dolphins had already died by the time they got there.
“Luckily, it is cooler today, but these animals will risk sunburn and overheating until the tide rises, and then we have the challenge of herding them into deeper water,” Hedman said earlier in the day.
The International Fund for Animal Welfare responded to 125 Atlantic white-sided dolphins that were stranded off Great Island at the Herring River in Wellfleet off Cape Cod on Friday, June 28, 2024. IFAW reported 10 died before they arrived Friday morning. The stranding is “the largest single mass stranding event in IFAW’s response history over 25 years,” they reported.Courtesy International Fund for Animal Welfare
The team tagged each of the dolphins and put sheets on them to keep them from getting sunburned, according to Niemeyer.
Eventually, at least 25 IFAW staff and 100 IFAW-trained volunteers were helping the dolphins Friday morning into the early evening, Hedman said, with help from Whale and Dolphin Conservation (WDC), the Center for Coastal Studies, AmeriCorps of Cape Cod and the New England Aquarium.
As high tide began at 4:56 p.m., teams used three small vessels in the water to “continue herding and using underwater pingers (noise) to urge the dolphins in the right direction,” according to Hedman.
Atlantic white-side dolphins, which usually grow between 8-9 feet in length and can weigh between 400 to 500 pounds, have a distinct “streamlined body,” small beak, tall dorsal fin and a “bold complex coloration pattern” of a dark gray top with lighter gray sides and a white underside, according to NOAA Fisheries.
Hedman said the 125 Atlantic white-sided dolphins represent the “largest single mass stranding event” in IFAW’s response history in the past 25 years.
Niemeyer said scouts will continue to monitor the dolphins Saturday to ensure they’ve headed out of the harbor. If necessary, they will be removed from the water using special equipment and placed into deeper water, likely off Provincetown, she said.
“The Gut,” an area near Great Island and Herring River in Wellfleet. This area is tucked along the west side of Wellfeet on the Cape Cod Bay side.Google Maps
