MOUNT DESERT ROCK — A mayday call received around 6:40 p.m. Sunday has triggered a massive air and sea search for a fishing vessel.

Paul Conner, a spokesman for the Coast Guard base in South Portland, said an unidentified fishing vessel sent out a distress call saying it was taking on water. The transmission was very faint, he said.

The Coast Guard sent a helicopter, an airplane, a motorized lifeboat and a patrol boat to search the area off Mount Desert Rock, a small island about 18 nautical miles south of Mount Desert Island. There is an automated lighthouse on the island.