James Milne Knott Sr. has accomplished many things in his life, from proudly serving in the U.S. Army to successfully challenging the Environmental Protection Agency — but he is best known over the range of the lobster resource for singlehandedly converting the industry from wooden to wire traps.

A lobsterman himself since the age of 12, Knott, 78, is the founder and owner of Riverdale Mills, the company synonymous with wire mesh for lobster traps.

“I put the first wire trap in the water in 1957, and it worked,” said Knott, and although eventually he succeeded, it took many years to convince other lobstermen the wire traps worked.

He never convinced the Connecticut mesh company he was working for at the time, however. Knott went started his own plastics company immediately after leaving the Army. He invented the plastic coating for wire mesh, coated fencing for a Connecticut company, eventually sold his firm to them and ran it for them for 16 years.

“It was all suits and ties and meetings,” said Knott. “I finally said I’ve had enough of this, I wanted to get back to basics.” He tried for years to convince the Connecticut company to target the lobster industry, but the vice president of sales kept telling him there was no market there. “Now my company is 12 times as big as theirs was when I sold my other company to them.”

He found a mill for sale in Riverdale, Mass., abandoned for four years but claiming a proud history and asking a reasonable asking. For $87,500, he acquired 75 acres, a 20,000 sq. ft. usable building and existing hydropower. He restored a 1901 turbine that saves $100,000 in electricity annually. The mill had started as a manufacturer of scythes and sickles in 1852, switched to bayonets for the Civil War, moved on to woolens, and last before Riverdale, produced high-quality wallpapers and wrapping papers for a German firm.

“I had only one thing in mind for the mill, to make mesh for lobster traps.” When he bought it, the family moved from their native Boston area to western Massachusetts, but continued to spend much of their free time in Gloucester where Knott had summered and spent weekends since his youth.

Convincing lobstermen to try the traps took years of trial and error — giving free traps to fishermen, finally concentrating on high liners, getting lots of negative feedback, but realizing the corner had been turned when one successful fisherman told him, “The stuff’s no good. Can you get me a couple more rolls?”

“Some people even accused me of being a secret conservationist, wanting to keep everyone from catching lobsters,” said Knott, adding that over the years he’s designed many traps that lobsters can’t get out of, “but they won’t go in, either.”

The big break for wire came when Pike Bartlett opened Friendship Trap in Friendship, Maine, and began making and selling wire traps. Unlike other dealers up to that time, Bartlett also offered kits, tools and training so lobstermen could make their own. Sales soared.

Since the 1980s, wire has replaced wood in the U.S. and made inroads in other countries, such as Canada. Knott has experienced ups and downs with dealers who switched to less expensive, foreign wire. Most returned to Riverdale.

When the mill had achieved unequivocal success, another problem surfaced: the U.S. Environmental Protection Agency (EPA) accused Knott of polluting the area around Riverside with acid, threatened him with six years in jail and big fines. Once, 21 armed EPA officials burst into the Riverdale lobby with guns.

“I’m a lobster fisherman, we don’t get intimidated, but they upset my employees,” said Knott, who demanded to see their federal warrant and threatened the officials with arrest if they failed to show it. Reluctantly, they did. As it turned out, someone at EPA had changed the numbers on a report, making Riverdale look guilty. The EPA continued to pursue the case despite negative independent lab tests.

“When I showed they had falsified the records, they offered me half a million dollars to go away,” Knott said. Instead, he won the right to depose EPA officials and videotaped the proceedings. When a senior counsel with the EPA asked him why he wouldn’t just take the money and drop it, he answered: “On June 11, 1954, I took an oath as an officer in the U.S. Army that I would defend this country against all enemies foreign and domestic.”

His victory attracted national attention. He appeared on “60 Minutes” and “20/20.” Since then, the trap business has ebbed and flowed — foreign wire cut into his business, dropping Riverdale from 90 percent of all lobster industry sales to 60 percent. It’s back up to 70 percent now, but he has another client — the U.S.-Mexico border fence.

“Used to be, the lobster industry was 100 percent of our business, now it’s a small fraction,” he said. Knott holds seven patents, Massachusetts licenses as a hydropower operator, a lobster fisherman and a construction supervisor and a federal commercial vessel operator’s license. He’s won awards for business and conservation, has published works through his alma mater, Harvard, served on many boards and is sought after as a speaker.

But he’s taking it a lot easier these days. “I’m semi-retired,” admitted Knott. “I’m down from 80 hours a week to only around 60.”