PORTLAND, Maine — A new lobster processing business could bring more than 50 jobs to a city-owned waterfront building that displays an iconic mural facing the Maine State Pier.

On May 14, the planning board approved the site plan and conditional use permit allowing Shucks Maine Lobster to occupy almost 19,000 square feet in the Portland Ocean Terminal at 6-40 Commercial St.

The approval allows owner John Hathaway to expand operations from Richmond to Portland.

Hathaway last week said renovations needed for a loading bay door and space for a liquid nitrogen tank will not come at the expense of the “Whaling Wall” painted by artist Robert Wyland in 1993.

“The whales themselves on the wall are not impacted at all,” Hathaway said. “I like the wall. It is a good piece of the working waterfront history.”

In a phone interview Saturday from outside Monterrey, California, Wyland expressed gratitude his work would be preserved.

“That’s great. That would be the optimum if he could do that,” Wyland said. “It’s nice when they consider it as a part of the community.”

Hathaway said he was not certain when Shucks would open, but it could almost double its space in the building by 2016 because the 15-year lease with the city has an option for up to 34,000 square feet.

Using pressurized cold water in a machine called the “Mother Shucker,” Shucks can process and ship raw lobster globally, which allows longer shelf life and opportunities for chefs to create dishes as they wish, Hathaway said.

At 16 feet tall and 80,000 pounds, the unit kills lobsters in six seconds. It is endorsed as “humane” by People for the Ethical Treatment of Animals, according to Shucks’ Planning Board application.

The process also allows easier separation of lobster meat, which still requires people, not automation.

“The pressure does not shuck the meat, everything we do is hand shuck,” Hathaway said.

That could mean about 50 seasonal jobs during peak processing times from May to January. The planning board application said work could be done in multiple shifts, but Shucks will try to limit shipping and receiving operations to between 6 p.m. and 2 a.m. for less disruption on the Maine State Pier.

Wyland suggested it might be time to return to Portland to freshen up the almost 950 feet of painted whales along the corrugated metal exterior.

“Corrugated is hard, really hard to work with, but I think it gave it a lot of character,” Wyland said. “It was very, very challenging. That’s the character of murals, it’s not a perfect canvas.”

The work was the first of 17 Wyland murals along the East Coast, including projects in Boston, Portsmouth, New Hampshire, and Key West, Florida.

The work was not commissioned by the city and is not protected as public art. Wyland said he could legally challenge any alteration of the work but appreciates that Shucks is a marine-related business.

“I try to protect them as much as I can, but I [also] try to use common sense,” he said about his murals.

Shucks’ arrival also will generate at least $200,000 in revenue annually for the city. A lease approved by city councilors last July sets the initial rate at $10.54 per square foot, with rent increasing by 2 percent annually.

Hathaway, who ran unsuccessfully in 1996 for the Republican nomination for the U.S. Senate seat held by Sen. Susan Collins, R-Maine, is financing the expansion through a $3 million loan from the National Marine Fisheries Service in Gloucester, Massachusetts.

The agency is part of the National Oceanic and Atmospheric Administration and has a Financial Services Branch that provides loans for marine industries at interest rates “2 percent above the U.S. Treasury’s borrowing cost for similar maturities,” according to its web page.

A minority partner in the Shucks expansion is Linda Bean, owner of seven restaurants including locations at the Portland Jetport, Maine Mall and in Freeport.

Hathaway said he is looking forward to expanding the Shucks name and customer base while continuing the marine industry tradition on the city’s waterfront.

“We are very sensitive to what it takes to open a business in Portland and to how dedicated [officials] were to preserving the working waterfront,” he said.