SALEM — The blue waters of Salem Sound, which extend from Marblehead to Manchester-by-the-Sea, are the first stretch of North Shore waterfront to ban boaters from dumping sewage.

The Environmental Protection Agency announced yesterday that it has approved a request from Gov. Deval Patrick to declare the 54 square miles of Salem Sound a "no discharge" area.

"This really helps to make sure that this wonderful resource is protected for many years to come," Salem Mayor Kim Driscoll said yesterday during a public announcement at the city's ferry landing.

The ban on dumping even treated sewage from vessels is now law for the estimated 8,000 boaters who navigate off Salem, Marblehead, Danvers, Beverly and Manchester-by-the-Sea. Violators face fines of up to $2,000.

This is "another leap forward in cleaning up Massachusetts' coastal waters," said Stephen Perkins, an official with the New England office of the EPA.

Salem Sound Coastwatch, a Salem-based environmental group, was credited with playing a lead role in the no-discharge designation and with alerting officials to the extent of the problem. A report by the agency showed that 15 percent of boaters responding to a survey, or about 120 boat owners, admitted dumping waste.

"That was alarming," said Leslie-Ann McGee, director of the Massachusetts Office of Coastal Zone Management.

This new regulation will be enforced by local boards of health and harbormasters.

Driscoll announced yesterday that Dominion, the owners of Salem Harbor Station, donated $20,000 to help the city purchase a new pump-out boat to replace an old one.

"For the boating public, it means you have no reason not to comply," Driscoll said.

A Danvers officials said they will use $19,000 approved at Town Meeting and other funds to buy the town's first pump-out boat, which should arrive in September. Beverly, Marblehead and Manchester have pump-out boats.

Several of the communities also have working pump-out facilities in docking areas.

"Our next job is to educate the boaters," Barbara Warren of Salem Sound Coastwatch said.

Salem Sound is the state's 10th no-discharge area.