ORRS ISLAND — Federal officials arrived here Wednesday to try to find an escape route for a 30-foot humpback whale trapped in Lowells Cove, where it has spent the past month feeding on pogies.

The National Marine Fisheries Service said the whale had become entangled in a 500-foot-long fish net strung across the cove to collect pogies which are sold as lobster bait.

Dr. Charles “Stormy” Mayo, a whale disentanglement expert from the Center for Coastal Studies in Provincetown, Mass., visited the area, accompanied by a marine mammal expert and an attorney from the fisheries service.

Charley Shepherd, a spokeswoman at the fisheries service regional office in Gloucester, Mass., said that when there was some distance between the whale and the pogies, officials would lower the net and let the whale out and then raise the net to prevent the pogies from escaping.

She said it probably would be done Thursday.

The whale was first spotted in the cove on July 3, having apparently been lured there by the prospect of an endless supply of available food.

The net’s owner, Alden Leeman of Orrs Island, estimates that the whale has already consumed $7,000 worth of pogies. He said the remaining 800,000 pounds, worth $80,000 to $100,000, might escape to open sea if the net were to be lowered to free the whale.