Robotic shellfish farming and carbon in kelp are among ecosystem services under development at Running Tide Technologies.

HARPSWELL, Maine — Along the shore of the Damariscotta River, what appears to be a white sand beach is actually crushed oyster shells, sun-bleached over the thousands of years since Indigenous people consumed the shellfish before they disappeared from the river. 

Rebounding in popularity in recent years, oyster farms now line the coastline of Maine, with harvests up more than 50 percent last year. The work can be grueling, with farmers regularly flipping heavy bags of oysters in the sea in order to nurture the shellfish. 

One Maine company, backed by millions in venture capital funding, is rethinking that process, employing engineers, software developers, and scientists to build a better oyster farm using, essentially, robotics. 

But these oysters, nurtured in a high-tech hatchery and carefully raised in Middle Bay before heading to markets like South Portland Seafood, are not the end product for Running Tide Technologies. Their focus is on developing ecosystem services, including floating kelp buoys designed to capture carbon, in an effort to “rebalance the ocean.” 

On an aluminum processing vessel floating in Middle Bay Tuesday morning, Capt. Nate Porter fed 2-year-old oysters along a conveyor belt to be photographed and measured by a camera before dropping into a bin.

At the bow of the boat, data collected by the camera were visible on computer screens.

Two coves over, nursery vessel manager John Clapp, an engineer, checked the temperature, salinity, and dissolved oxygen level of the bay. These and other factors, measured by a small yellow buoy floating nearby, are critical to maximizing the growth of the young oysters resting in bins below the boat.

Selecting one of the just-measured oysters, Running Tide’s director of shellfish, Adam Baske, pointed to an outer edge of the shell.

“That edge there, they call it the fingernail,” he said. “That’s the new growth since the last time we handled them. That’s a quarter-inch, half an inch of growth, since a few weeks ago.”

Carefully shucking one, Baske said oysters that grow even one bay over taste different.

“Our particular location has a really interesting taste,” he said. “People have said it has a little bit of umami, not an overpowering brine but a nice briny taste at the start that kind of lingers after you get it down the hatch”

The oysters were transferred about two weeks ago from a hatchery on nearby Harpswell Neck. There, in a renovated fire station building, senior biologist Karl Eschholz oversees oysters and surf clams in various stages of growth.

Eschholz, who Baske calls the “mastermind” of the hatchery, pointed to bottles of American oyster seed of various sizes lining one wall. Water bubbles up from the bottom and food filters into the bottles.

“This could grow two to three times in days,” Eschholz said.

He and his team feed the seed algae formulations found in glass tubes of various shades of green in an adjacent room.

“It’s like a really technical farm,” Eschholz said. “We’re taking care of every parameter that these animals need.”

Nearby, hatchery tech Jessica Giles sprayed surf clam seed through a stack of mesh trays that sorts them by size. The process allows her to check the health of the clams and collect data.

“They grow best when they’re with similar-sized clams,” she said.

While the shellfish operation is the most visible to Mainers, it’s Running Tide’s plan for using kelp to capture carbon that’s been the focus of recent national media attention in recent months, Running Tide is also devoting time and resources to a method of permanent carbon removal using macroalgae, or kelp.

“Thousands of scientists are saying that clearly not only do we need to reduce emissions, we actually need to remove a lot of this excess carbon that’s in the sky,” Baske said, referring to a recent report by the Intergovernmental Panel on Climate Change. 

“We’re talking hundreds of gigatons that’s up in the sky that needs to be permanently removed. … We need to get it back to where it came from, which is the slow carbon cycle, deep into the earth or deep into the ocean,” he continued. “It’s really, how do you most effectively kind of tap into Mother Nature to bring that carbon from the fast cycle and bury it down into the slow.”

Based largely in Iceland, Running Tide is developing a system to capture carbon by coating biodegradable “pucks” made of wood waste, with kelp spores. The fast-growing kelp, as much as a foot per day, would be floated in carefully selected areas of the ocean where, as they degrade, the kelp will grow, capturing carbon through photosynthesis.

“When that puck becomes waterlogged, the whole system sinks into the deep, deep ocean,” Baske said. “There’s extreme pressures down at that depth and that carbon is essentially locked away for a thousand years and up to many, many more.”

“The scale of the challenge is so big,” Baske said. “You’ve got to have systems that throw machinery at it and automation, but you’ve always going to have people directing and running these systems. You’ve got to have eyes because these are animals.”

“What we’re building is really a system for repairing or restoring coastal ecosystems around the world,” Baske said. “With coastal degradation, with water pollution, and especially with climate change, we’re trying to think of different systems … how can we tap into nature’s natural ability to filter water, to buffer against ocean acidification, and overall improve the ecosystem. How you do that is with growing shellfish at scale.”

Running Tide’s founder and CEO, Marty Odlin, comes from a long line of Maine groundfishermen. He realized early the uncertainty of wild-captured fisheries.

“It’s like a desert and just within my lifetime,” Odlin told The New York Times of changes to the ocean.

Fresh with an engineering degree from Dartmouth College, Odlin started building equipment in his South Portland backyard.

His goal, Baske said, was, “How can we turn a profit by tapping into the ocean and technology, and doing it in a way that’s better for the world, and for a more livable future?”

Odlin’s ideas about applying technology to aquaculture quickly attracted the attention of venture capitalists. The company has also begun selling carbon-capture credits.

Today, Running Tide employs about 100 people, Baske said, 70 of them in Maine, including software engineers, fabricators, welders, biologists, lab techs, and fishermen.

One oceanography expert told The Atlantic that questions remain about how much carbon would remain in the kelp as it sinks, and how much carbon absorbed by the kelp is removed from the atmosphere in the long term.

Last month, Ocean Visions announced an independent scientific advisory board to review the carbon capturing technology.

Baske said Running Tide is confident a market will emerge for ecosystem services.

“What we’re working towards is a world where there’s a market for these ecosystem services, whether it’s nutrient removal or biodiversity,” he said. “All those things have value. Everyone in the world appreciates those things. There just aren’t markets for them yet. We’re building a system to tap into that market when they do exist, and we think they’re on their way.”

Watch Marty Odlin’s talk at the Stockholm Climate Summit here: