MIDDLETOWN — Marine biologists found two dolphins on a sandbar near a state marina and had to euthanize one of them because of its weakened state. An adult common dolphin discovered Wednesday afternoon on the beach between the Naval Weapons Station Earle eastern beach and Leonardo State Marina beach was already dead. Its calf was spotted 150 feet away on a sandbar near the Naval Weapons Station Earle pier, according to the Marine Mammal Stranding Center.