One of them died Monday. Now with a second one dead, Schoelkopf says the animals will be taken to a veterinary clinic at the University of Pennsylvania to try to determine the cause of death.
The three are not part of a group of bottlenose dolphins that have been in the Shrewsbury and Navesink rivers since June.
Schoelkopf says local law enforcement erected a tent around the stranded dolphin to shelter it from the bitter temperatures, but it died on the beach.
TV footage on News 12 New Jersey showed the dolphin shaking.
