FREEPORT, Maine — As researchers from Casco Bay to Frenchman Bay study the lifestyle and diet of invasive European green crabs in an effort to control the predators, a North Carolina company hopes to find Mainers willing to sell the creeping crustaceans to be processed into cat food.

Bay City Crab purchased two tractor-trailer loads — a total of 22,000 pounds — of crabs earlier this summer from Boothbay Harbor-area harvesters and processed them at their plant based in Aurora, North Carolina. The firm then shipped the crabmeat to a cat food company, plant manager Chrissy Fulcher said Friday.

Fulcher would not disclose the name of the company to which she sold the processed crabs, but she said Bay City Crab — which processes domestic blue crabs “for five-star restaurants in New York and Boston” — has found a market for the green crab that has devoured shoreline habitat and threatened the $16 million softshell clam industry in Maine.

But just as the state of Maine loosened regulations around selling green crabs, the men who were selling to Fulcher said they were done. The 25 cents a pound she was paying “just wasn’t worth it [to them],” Fulcher said. “[One harvester] said he wasn’t catching the numbers [to make it worthwhile].”

Fulcher acknowledged the “very small price” but said other costs associated with the business — packaging the crabs in Maine, transporting them to North Carolina, manpower and transporting them to the cat food processing plant — made it impossible to pay more.

“We took the trailer up there and dropped it off in his yard,” Fulcher said. “We provided the vats and the pallets and everything. All he really had to do was go and dump them in the vat.”

In June, Fulcher and her husband traveled along Maine’s coastline, handing out business cards. Bay City Crab also has advertised in publications, including the Boothbay Register, hoping to find others interested in selling green crabs to them. She said many have contacted her since, but there have been no takers so far.

“I think the price probably plays into it,” she said. “I told a lot of them I’m hoping that if they would bear with us this year, we could make the market strong. And next year we might be able to raise [the price] a little bit.”

Still, Fulcher said harvesters from Massachusetts contacted the company last week, and there’s talk of buying them from that state.

Selling green crabs became easier this week, when the state of Maine relaxed regulations pertaining to the harvesting of green crabs, essentially streamlining the process and, among other things, eliminated the need for a license, according to Kohl Kanwit, director of public health at the Maine Department of Marine Resources.

“If you’re catching them while you’re out lobstering, you can go ahead and sell them,” Kanwit said.

The new regulations remove the restrictions on how many traps a fisherman can have on a string. The change also allows municipalities to get a Department of Marine Resources permit to harvest the crabs as part of a predator control program.

“We want to try to make it as easy as possible for people to try to get rid of them so they don’t impact the shellfish industry, which, including oysters, mussels and other species, brings in about $25 million annually,” Kanwit said.

But as options for catching and possibly profiting from the green crabs increase, the crabs themselves, it seems, are here in fewer numbers.

In Freeport, the annual catch is down from this time last year, though it is up over the past 13 weeks, according to Brian Beal, a researcher from the University of Maine at Machias and nonprofit Downeast Institute for Applied Marine Research and Education. Beal is leading six studies about the crabs in the Harraseeket River.

The crabs they are catching in Freeport, however, are concentrated in the intertidal zone — the valuable clam flats.

“I think they’re headed for the small clams [there],” Beal said.

Because data has only recently been collected on the predator, Beal said it’s still too early to see any pattern or to predict what might be in store for harvesters next summer.

“Was last year an anomaly, or is this year?” he said. “We really don’t know what we’re looking at.”

With the new regulations allowing municipalities to apply for a permit to sell the green crabs, Brunswick Marine Resources Officer Dan Devereaux said the town might consider selling them to offset the cost of trapping them. But this year, at least, they’re not catching many.

“Twenty-five cents a pound doesn’t even pay for the gas to go out and fish them,” he cautioned.