ORRS ISLAND — After a whale of a meal that lasted a month, a 30-foot humpback swam from a cove along Maine’s coast to the open sea on Friday.

Attempts to lure the whale out of the cove with food and recordings of other whales failed, so fishermen finally cut the hungry humpback off from a seemingly endless supply of menhaden it had been feeding on. Menhaden, or pogies, are used as fishing bait.

Fishermen on Friday herded the pogies to the back of Lowell’s Cove and contained them with a net barrier. Then they dropped a section of another net that had been strung across the mouth of the cove, hoping the whale would see the opening and swim to sea.

“It swam by and checked it out” a couple of times before swimming to the open ocean, said Colleen Coogan, a marine mammal specialist with the National Marine Fisheries Service. “We were happy to see it was swimming very strong.”

Since the humpback first arrived July 3, visitors to the cove have arrived by boat and by car to catch a glimpse of the whale. Coogan, who had been at the site a total of eight days, estimated the whale’s weight at 20 tons.

Coogan said the whale flukes, or tail, were injured from scraping against the nets and rocks in the cove. She said the whale was breaching, leaping out of the water, as it swam, apparently to rid itself of dead skin from its wounds and parasites that it picked up in the cove.

“It was not 100 percent healthy looking when it went into the cove, and didn’t change much while it was there,” said Coogan.

Coogan said she could not substantiate reports by local fishermen who said they had seen the whale swim over the top of a net in the cove.

“I think he’s just beat it out of town,” said fisheries service spokeswoman Charley Shepherd, adding, “Of course, it was a pretty nice free lunch.”

The owner of the net, Alden Leeman of Orrs Island, had estimated that the whale consumed at least $7,000 worth of pogies during its stay. He said the remaining 800,000 pounds of fish was worth $80,000 to $100,000.

“We cannot predict whether this whale is going to make it any more than any other whale,” she said.