Kohl Kanwit will never forget the tiny clicking sound she heard the first time she went to check out the green crab crisis for herself.

“It sounded like a horror movie,” said Kanwit, director of the public health bureau for the Maine Department of Marine Resources. As she crouched on the bank in Freeport for a closer look in the spring of 2013, she saw hundreds of the tiny 10-legged creatures scurrying about. “It was amazing.”

Now, public- and private-sector efforts are underway to prevent a green crab invasion from becoming a real-life horror to Maine’s $17 million soft-shell clamming industry and marine life along the Maine coast.

Green crabs prey on clams and wreak havoc on eelgrass. Although the critters, which can be anywhere from 2½ to 5 inches long, have been reported in Maine for more than a century, scientists speculate that warming ocean temperatures have allowed the crabs to multiply and move north.

Since April 2013, researchers have been trying to assess the damage green crabs are doing and how to effectively eradicate them. In December, hundreds of researchers gathered to discuss the issue at a Green Crab Summit. In February, Gov. Paul Le- Page ordered the creation of a task force to study their impact and potential solutions.

Four towns are studying the most effective ways to trap green crabs. The Department of Marine Resources is considering changing rules to make it easier to catch them. Meanwhile, entrepreneurs are exploring opportunities to turn the predators into profit by marketing green crabs for everything from fish food to gourmet meals.

“We need to figure out sustainable, cost-effective, long-term solutions to manage this issue so that they don’t have a huge impact on marine life,” said Kanwit. “The solutions have to be sustainable over the long haul.”

Last August, a green crab-trapping survey was conducted over two days in 30 locations along the coast. It confirmed the abundance of the invasive species. Of the 208 traps set, 193 had crabs in them. The findings were presented at the Green Crab Summit at the University of Maine in Orono, where 600 scientists and researchers gathered to discuss the issue.

Since last spring, Brian Beal, a marine ecology researcher at the University of Maine at Machias, has been doing a series of studies in Freeport, tracking crabs and assessing how they’re affecting clams in the area. Beal said he’s finding about one-tenth of the volume of green crabs that he and his team located this time last year. Some speculate that the winter weather was cold enough to kill off some of the population. But, he said, researchers in nearby areas – as close as Cousins Island – are coming in with hundreds of green crabs per trap and many are smaller juvenile crabs.

“It’s a puzzle with a whole bunch of pieces, and we’re just beginning to fit those pieces together to figure out what the picture looks like,” Beal said. “We don’t have a very long record of data to give us a definitive answer.”

Marine biologist Darcie Couture, who is involved in a number of green crab projects, has seen a surge off the coast of Harpswell in recent weeks.

“Now that we’ve had a stretch of warm weather, we’re going to see a little spike in the population, though maybe not the millions we saw last year,” said Couture, founder of Resource Access International LLC, a Brunswick-based consulting firm.

Scientists also are trying to determine what impact green crabs could be having on eelgrass, a marine plant that helps maintain fisheries, stabilize sediment and maintain water quality.

A group of federal, state and nonprofit agencies is trapping green crabs at five locations along the coast as part of a larger eelgrass study. A 2013 report showed a 58 percent decrease in eelgrass across Casco Bay since 2001, and green crabs were identified as a primary cause, said Hilary Neckles, a research ecologist with the U.S. Geological Survey, which is spearheading the current study. When the green crabs prey on clams, they dislodge and clip off eelgrass, she said.

Another leg of the effort is focusing on the best ways to get rid of green crabs.

During the most recent legislative session, a bill was signed that paved the way for municipalities to study different ways to control green crabs. Four towns – Freeport, Harpswell, West Bath and Brunswick – are conducting pilot projects, partly to determine if various fencing and netting techniques effectively rein in green crabs.

The Department of Marine Resources is considering rule changes that would make it easier to remove the invasive species. The proposed regulations include eliminating the restriction on taking green crabs caught unintentionally. Lobstermen would no longer need to get a license to sell green crabs, and they wouldn’t have to report what they harvested, as they do now.

There will be a public hearing on the proposed rule changes at 1 p.m. Monday at the Natural Resources Service Center in Hallowell. The deadline for public comments on the proposed rule changes is July 25.

As awareness about the problem has grown, so has the effort to harvest crabs. In 2013, there were 52 licenses to fish green crabs, and 10,596 pounds were harvested, according to preliminary data from the Department of Marine Resources. The year before, 36 licenses were issued and 3,762 pounds landed.

A number of entrepreneurs are looking at potential uses for green crab meat and shells. Christina Fulcher, manager of Bay City Crabs, a seafood processor based in Oriental, North Carolina, traveled to Maine last month to explore the feasibility of processing green crab meat.

Ron Howse, a businessman based in Ellsworth, is also trying to make a market in green crabs. He said he is negotiating to buy a 3,500-square-foot plant in Sullivan to process green crabs, rock crabs, Jonah crabs and lobster. He said he’s planning to hire up to 80 people in the next year, and he has deals with more than 40 fishermen to purchase the crabs. Howse said he has a letter of intent with a frozen food company to buy green crab meat and is working on deals to supply live crabs to companies in Asia.

An Arundel-based businessman, John der Kinderen, got a cluster grant from the Maine Technology Institute to study the feasibility of using green crab meat and shells for a variety of purposes. His company – Waste Not, Want Not – is exploring ways to efficiently extract meat so that it can be eaten or processed for other uses such as food for farmed salmon. He also is exploring the potential to use an extract from green crab called chitin.

“I knew this was a resource that was just waiting to be utilized,” he said, “but we really haven’t even explored all the possibilities yet.”