The carcass of a 30-foot humpback whale washed up on a New Jersey beach Saturday morning. Members of the Marine Mammal Stranding Center in Brigantine were called to the a beach in Strathmere, named Whale Beach, where they discovered the body of the whale, estimated to weigh 20 tons, said Sheila Dean, co-director of the center. “It was badly decomposed, so we were not able to determine the cause of death,” Dean said. She said a decomposed whale requires a larger staff to open up the carcass and perform an autopsy. The whale was determined to be under 10 years old and considered a juvenile, Dean…