Wayne Ledwell of Whale Release and Strandings in Portugal Cove-St. Philip's said Monday the dolphins were first spotted the night before near Cape Ray.
By late Monday afternoon, Fisheries and Oceans said all but three of the mammals had died.
The department says its officers confirmed the deaths of all the animals today.
White-beaked dolphins, which can weigh up to 300 kilograms, are usually among the first of whales, dolphins and porpoises to arrive in the waters around Newfoundland as spring approaches, Ledwell said.
As a result, they are also the ones most prone to getting trapped, he said, adding that a much smaller group was reported trapped offshore earlier this year.
Ledwell said his records show more than 400 whales, dolphins and porpoises have been reported trapped in the ice since the 1970s.
The Fisheries Department said six blue whales -- the largest animals on the planet at up to 30 metres long -- were driven ashore by ice in 1987.