TRENTON — The de Köning family has operated their mussel business from a facility at 806 Bar Harbor Road in Trenton for the better part of 10 years.
They were just finishing building a new processing facility there in 2015 when it was completely destroyed by a fire. Co-owner Theo de Köning said he and his sons, Alex and Max, left the plant and returned home only to be called by a neighbor to tell them the building was ablaze.
“They never found out what happened,” he said.
During construction of their new plant, Hollander and de Köning Mussel Processors worked in a complex owned by Evan Young of Blue Hill Bay Mussel, and Young offered to let them move back while their plant was rebuilt.
The building was insured, and the business was back up and running within six months.
Theo, a native Dutchman and a fifth-generation mussel farmer, moved to Maine with his wife, Fiona, originally from England, in 2005.
They had explored settling in Chile or New Zealand but chose Mount Desert Island. Their home is in Salisbury Cove, and their processing plant and offices are on Route 3 in Trenton.
Theo de Köning worked under the umbrella of Great Eastern Mussel Farms when he arrived in Maine. When that company closed in 2008, the de Könings started their own farming operation.
The de Köning family farms in the trademark “Dutch” style, dating back hundreds of years. The mussels are grown on the sea bottom, rather than on ropes that hang down from floats moored in the lease area.
They hold five aquaculture leases, totaling 157 acres, from Bean Island to Trenton.
“They outlawed wild harvest [in the Netherlands] in the 1700s as nonsustainable,” Fiona de Köning said. “It’s been a version of aquaculture since then and we wondered if that would work here.
“It was a big experiment,” she said. “Nobody was actually doing what we do here and, as far as I can see, I haven’t seen a bottom-cultured mussel farm anywhere in the United States.”
The business has 12 employees, including Theo, Fiona , Max, 18, and Alex, 27. Their daughter, Charlotte, 29, is a first-grade teacher in Presque Isle.
Alex de Köning recently graduated from the University of Maine with a mechanical engineering degree. He designed much of the equipment in the processing plant himself.
“I’ve got two boys who might have very well moved out of state for employment,” Fiona de Köning said. “Now they are happily working here.”
Aquaculture “helps towards food stability in the United States,” she said, because growing shellfish helps increase biomass in a given area. The practice also requires fewer inputs than farming other meats, she said.
Fiona de Köning also serves on the Marine Resources Committee in Bar Harbor, along with other state and international committees working to improve aquaculture practices.
The process of growing mussels on the seabed is much like planting a garden. The “seed” — mussel larvae — is grown in “seed banks” that the company manages. Behind their Trenton building, there’s a seed bank that simply looks like a pile of old mussel shells to an untrained eye.
“They set seed in huge quantities because they’re eaten at every stage of their life,” Fiona de Köning said. “When they seem to sense it’s a good place for mussels to live, they rain down in huge quantities in one place.”
The seed is spread in an area of a lease from which market-sized mussels were just harvested. Mussels naturally congregate in small areas, so farmers have to spread them out to make sure each one gets the proper amount of oxygen and nutrients.
The mussels are harvested by a specially designed drag that operates more like a scoop. Theo de Köning does all of the mechanical work from their boat, Stewardship. The scoop, while it looks cumbersome, is light enough to disturb only the first layer of sediment under harvested mussels. He said it even flaps in the wind when he leaves it out of water behind the boat at high speeds.
The mussels, after they’re off the boat and cleaned, are fed through a $250,000 machine that takes a picture and collects data on every individual mussel. Those mussels are then quality checked and packed into bags. The bags are stored in boxes filled with ocean-water ice slurry to keep them fresh. Through the whole process, the mussels are immersed in ocean water pumped in from behind the processing plant.
Fiona de Köning estimated that the company processes 1 million pounds of mussels every year. Their volume is wholly dependent on the orders they receive, harvesting that specific amount from their leases. They harvest three days a week.
The business is still considered a start-up, though, because larger operations can produce upwards of 19 million pounds.
Their lease areas are unobtrusive for shorefront property owners, lobstermen and other boaters, she said, because the leases extend only a couple hundred feet from the shore and buoys only mark the corners of the leased area.
“The coast of Maine [has] a different mix of people,” she said. “We find this form of aquaculture fits alongside the lobster fishery because we harvest in muddy, shallow areas.”
Growing on the seabed also leaves room for predators like starfish and eider ducks. The company has an agreement with a diver who collects starfish in the leases to sell to the University of Maine for research.
In the early years, Hollander and de Köning sold mussels directly to restaurants, but they found it was not cost effective to make small-scale deliveries. Now they work with distributors across New England.
Since mussels filter water for food, their taste is built up through the minerals they retain during the filtering process. Growing mussels on the seabed, Fiona de Köning said, gives more opportunity for mineral and salt water intake, making them taste better.
Theo de Köning built a smoker from a metal household garbage can that he often uses to smoke mussels.
“I wouldn’t buy seafood from someone that doesn’t eat their own product, would you?” Fiona de Köning said.