PORTSMOUTH, N.H. — A $17 million harbor project scheduled to begin Friday will temporarily disrupt business in Portsmouth Harbor but will be a boon to the local economy in the long run, says Port Authority Director Thomas Orfe.

“To me, it’s a turning point for the port,” said Orfe. “The pier, in the long term, will pay for itself.”

The massive, three-pronged barge wharf expansion is scheduled to begin on Friday and to be completed in just under a year.

Seventy-five percent of the project is funded by a federal Economic Development Administration grant and another 25 percent is coming from the state, Orfe said.

The project will not be completed without some disruption, however.

Eight fishermen will have to move their lobster pots from the vicinity and will not be able to harvest their lobsters for 60 days during the dredging and blasting.

“I’m sure this is a major inconvenience,” said Orfe. Dredging will take place during prime harvesting season.

Dredging does not ordinarily kill any of the stock below the water, Orfe said, so the lobsters and crabs will migrate to other parts of the river.

“We’re trying to be sensitive as we go,” said Orfe.

The lobstermen who own the pots have been notified of the fishing ban, but Orfe said if the project`s start is delayed for more than a few days, the lobstermen will be notified they can fish during the delay.

The first phase involves dredging the mud, silt, sand and gravel that has settled on top of the rock river bed. When that is completed, two or three weeks of blasting will be necessary.

Orfe said no blasting will take place, however, while the USS Maine is at the Portsmouth Naval Shipyard. The submarine will be commissioned July 29.

The U.S. Coast Guard is enforcing a safety and security buffer zone around the Navy yard and the submarine while it is in port.

The Port Authority also is weighing various proposals on how to lift the ill-fated Engine 3666, which plunged into the Piscataqua in 1939. Orfe said the train wreck will be raised sometime in the next five weeks.