BELFAST — Park by the waterfront in Belfast and stroll up Main Street, toward the post office.

If you’ve been here before, you might think the place looks or feels a bit different.

More lively, perhaps. Or, more energetic.

Since last fall, some 28 new businesses have opened in this Midcoast seaside town, and another 19 have expanded or relocated within the city.

The new shops are filling formerly vacant storefronts and injecting life into a downtown once dominated by long-departed heavy industries.

“For a town this size, it seems like a staggering amount (of new businesses),” said JB Turner, president of Front Street Shipyard, which opened this year. “The people are excited and the town is vibrant. The streets are packed.”

“There’s a buzz about Belfast,” said Dorothy Havey, executive director of Our Town Belfast, a new group that promotes the downtown district. “The city (has) set the tone to make Belfast a place where businesses are welcome.”

New shops include Clean Bee Laundry, bookstores like Bellabooks and Antiques and Artisan Book and Bindery, clothing retailers such as underwear shop City Drawers and art store Fiddlehead Artisan Supply. There are also new restaurants and a new marine architect firm.

Some business people thank the city for helping them get started.

“Everybody likes to take potshots at the government, but these guys are working for you and moving things ahead for Belfast,” said Turner at Front Street Shipyard. Front Street builds custom yachts, owns a 22-slip marina and operates a 165-ton boat lift.

In January, the shipyard bought the waterfront land formerly occupied by the Stinson Seafood sardine cannery, which left in 2001. Turner said the city worked with the shipyard and eased local height restrictions and setback requirements.

“We needed their support and help in getting rezoning,” Turner said.

City officials also helped entrepreneurs Mary Johnston and her husband, Garry Conklin.

The couple, who moved to Maine a few months ago from Cambridge, N.Y., spent the spring scouting Maine for the best city to open a small business.

They called economic development departments in different towns, but sometimes waited weeks for appointments. Belfast officials, however, offered to meet them the next day, and helped the couple find a location.

“They were more energetic and enthusiastic than anyone we had talked to,” said Johnston. “There were emails back and forth, and follow-up. They were like your family.”

Three weeks ago the couple opened two businesses from the same storefront: Conklin runs Conklin’s Maine Mercantile, a retail shop selling kitchenware and other home goods, and Johnston runs Mary Johnston Design, an interior decorating firm.

The job of supporting small business falls to Thomas Kittredge, Belfast’s new economic development director. Kittredge, who started in June, is the first person to hold the position since the 1980s.

City Manager Joseph Slocum said Belfast hired Kittredge as part of a broad effort to promote the area’s economy.

“There was definitely a push by the city council to enhance economic development efforts,” he said.

And it’s not just small businesses Belfast is after.

Kittredge and other officials are trying to recruit large manufacturing companies, including those that make and assemble offshore wind energy equipment.

“We are not just sitting back and letting the world go by,” said Belfast Mayor Walter Ash Jr. “We are out there hustling, trying to become a destination point. The goal is to get people coming to our community and, hopefully, leaving dollars here so everybody can survive.”

The city’s efforts, and those of business groups like Our Town Belfast, seem to be working.

In addition to the new businesses, the Maine Downtown Center designated Belfast a “Main Street Maine” community in June. The designation means Belfast has access to resources and studies to help revitalize the city’s historic downtown.

And community development group MaineStream Finance began offering “Incubators Without Walls,” a course in small business development, in Belfast earlier this year.

Slocum said new businesses have diversified the local economy, which historically was dominated by heavy industries like shipbuilding, shoe and clothing manufacturing and poultry processing.

He said the community was devastated by the decline of the poultry industry in the 1970s and 1980s, but revived in the mid-1990s when credit card company MBNA opened offices in Belfast.

Today, Bank of America Corporation, Belfast’s largest employer, and Athenahealth Inc., have offices in the former MBNA facility.

But small businesses rule downtown, and new arrivals are filling formerly empty storefronts.

“A few years ago you could walk down Main or High streets and see six or eight vacant stores,” said Tim Gordley, owner of Hawkeye Computer Repair on High Street. “Now, there are a couple.”

But Gordley, who has lived in Belfast six years, has seen many shops come and go. And he thinks Belfast, which has no big-box stores, needs more “utilitarian” shops that sell everyday goods.

To buy a houseplant, he said you must drive nearly an hour to Thomaston.

“There’s lots of galleries,” he said of Belfast. “But less of the stuff you need year round.”

But Turner at Front Street Shipyard said the kind of shops and amenities Belfast does have attract out-of-town boaters to the town.

“If they don’t have restaurants and bars and a movie theater and laundromat, they aren’t coming here,” he said.