The largest mass stranding of dolphins in United States history occurred off Cape Cod, Massachusetts, starting on June 28, 2024. This unprecedented event lasted five days and involved 146 dolphins, with 102 surviving the ordeal. The stranding took place in Wellfleet, about 15 miles southeast of Provincetown, and was closely monitored by the International Fund for Animal Welfare (IFAW).

A Record-Breaking Stranding Event

The IFAW noted that the geography of the Herring River ‘Gut,’ characterized by its hook-like shape and extreme tidal fluctuations, makes it a common site for animal strandings. On June 28, early reports indicated about 10 Atlantic white-sided dolphins near the shore. However, upon arrival, IFAW staff and volunteers discovered a much larger group, estimating 125 dolphins in total, with 10 already deceased. Misty Niemeyer, IFAW’s stranding coordinator, described the scene as “a global epicenter for mass strandings,” highlighting the gravity of the situation.

The Rescue Effort and Challenges

The rescue operation was a massive undertaking involving staff and volunteers to herd the dolphins into deeper waters. Initially, they attempted to move the dolphins on foot, but as the tide rose, they switched to using boats. The challenges were immense, including the large number of dolphins, their significant size, and the difficult mud conditions. Niemeyer acknowledged the exhausting nature of the 12-hour rescue effort under the relentless sun but praised the team’s dedication and perseverance.

By sunset on June 28, most dolphins had made their way to deeper waters, but about 12 remained in the inner harbor. The IFAW reported that among the 146 stranded dolphins, 37 died naturally, seven were euthanized, and 10 were extracted and released. This effort resulted in a survival rate of approximately 70%, a significant achievement given the circumstances.

Community Response and Future Preventive Measures

The mass stranding event elicited a strong reaction from the local community, who felt anxiety and fear for the marine animals. Many residents, including Katie Carrier, an administrative assistant at a nearby country club, rushed to help the dolphins. Carrier emphasized the need for proactive measures to prevent such incidents, suggesting investments in equipment for aerial surveillance of dolphin pods to anticipate potential strandings.

Brian Sharp, director of the marine mammal rescue team at IFAW, advised that anyone who sees stranded dolphins should contact local stranding responders or 911 immediately. He also recommended shooing away gulls, which can harm stranded dolphins.

The rescue involved over 150 people, including at least 25 IFAW staff, 100 trained volunteers, and representatives from various organizations such as AmeriCorps of Cape Cod, Whale and Dolphin Conservation, the New England Aquarium, the Center for Coastal Studies, and the Wellfleet Harbormaster. IFAW veterinarians and biologists provided critical care to the dolphins using mobile rescue clinics. Satellite tags were placed on some dolphins to track their movements, and whale watchers have since reported seeing the once-stranded dolphins swimming with other groups, marking a hopeful outcome to a challenging event.