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September 4, 2017 FOCUS: Startups / Entrepreneurship

From seed to market: How one oyster farmer leverages a growing market

Photo / Fred Field Bill Mook with a bag of his prized oysters at Mook Sea Farm by the Damariscotta River in Walpole. Some of his oyster cages are visible in the background in the river.
Photo / Fred Field A bag with prized oysters from the Damariscotta River by Mook Sea Farm.
Photo / Fred Field Northern triploid 4 millimeter long (70-day-old) seed oysters

Bill Mook started Mook Sea Farm on the Damariscotta River in 1985, and today has bootstrapped his way up to becoming one of the Maine oyster industry's top producers.

A ceaseless entrepreneur, Mook has set the pace by investing in research, new equipment and a skilled workforce. As a result, in just the past decade he's been able to double annual hatchery production to 120 million seeds today, substantially increase feed production, expand his workforce from four to 24 and, in the past year, double weekly production of market-size oysters.

At the same time, he's been tackling issues related to climate change, both managing current impacts and developing predictive monitoring techniques that could help inform future mitigation measures.

Photo / Fred Field
Hannah Clark of Newcastle fills tubes with micro algae. The liquid is used as oyster food at Mook Sea Farm in Walpole, where she is a hatchery technician.

His efforts come at a time when chefs and consumers are buying more Maine farmed oysters than ever. Sales of farmed oysters hit $4.9 million in 2015, five times what they were just a decade earlier.

“Right throughout the great recession, market demand for half-shell oysters has grown — and it's still growing right now,” Mook says.

A growth strategy with multiple approaches

Photo / Fred Field
Amanda Clapp of Newcastle uses water and screens to sort tiny seed oysters by size at Mook Sea Farm in Walpole. She is a hatchery technician.

Mook's approach includes deployment of a suspension-cage system, called OysterGro, that allows him to harvest all of his market-size oysters and allows year-round harvest. This compares with uncertain harvest levels and seasonality of more common bottom-culture methods.

He invests in research leading to innovations such as methods for overwintering seed; a tidal-powered nursery system; a vessel and gear for mechanizing the use of OysterGro cages; and a unique, energy-efficient and highly productive system for growing microalgae that's used to feed juveniles.

He's developed strategies to monitor and manage the chemistry of seawater pumped into the hatchery, for factors like increased acidity, temperature, salinity and oxygen concentration, in order to maintain healthy larval production and predict future impacts of climate change. This year's construction of a seawater-temperature-controlled holding facility is expected to enhance industry-wide bio-security measures, already in place, that mitigate risks of outbreaks of pathogens in oysters that can be fatal to human. Also this year, he launched a new brand name for his oysters that, in addition to long-time brands, will accommodate expanded production.

Photo / Fred Field
Bill Mook of Mook Sea Farm brings up an oyster bag from one of his oyster cages on the Damariscotta River in Walpole.

Mook started out growing various types of shellfish, but settled on oysters in the late 1990s, when the industry in general began taking off in Maine due to the availability of selectively bred disease-resistant oysters.

“It was the inception of what I call 'the new oyster renaissance,'” Mook says.

He and other early oyster growers, like Glidden Point Oyster Farms and Pemaquid Oyster Co., settled on the Damariscotta River, where pristine, cold Atlantic water mingles with warmer water upstream for a nutrient-rich environment. The industry today continues to grow, as newcomers enter the scene, the geographic scope of the industry expands, and oyster tourism initiatives take off.

Small but growing industry

Oysters are one of Maine's top three farmed species (along with Atlantic salmon and blue mussels), says the 2017 Maine Aquaculture Economic Impact Report, published by the University of Maine Aquaculture Research Institute. Maine has 65 to 80 oyster farms.

Modern shellfish aquaculture in Maine started at Darling Marine Center in Walpole in the 1970s, when researcher Herb Hidu was hired by the University of Maine, according to the Darling Marine Center. Hidu established a program focusing on the cultivation of blue mussels and oysters. His efforts led to many of his graduate students founding farms on the Damariscotta.

Maine Department of Marine Resources data illustrate harvest growth: from 2 million oysters in 2005, worth $848,338, to 7.6 million in 2015, worth $4.9 million. Production has long catered to the high-end market but new mid-market seafood shacks are popping up.

Maine's oyster industry is growing but still relatively small, says Dana Morse, an extension associate with Maine Sea Grant and University of Maine Cooperative Extension. Morse is based at DMC.

“The number of distinct oyster farming operations in Maine is increasing. But the state of Massachusetts, for example, has about 350 distinct oyster farming companies,” says Morse. Virginia is the East Coast's largest farmed oyster producer, selling 35 million in 2015. “From the point of view of area covered, Maine's shellfish farming industry, including mussels, is about 700 acres, which is a pretty small footprint,” Morse continues. “Across the nation, Maine is on the smaller end of the spectrum. Although we obviously have the best oysters.”

Most of Maine's production centers on the Damariscotta, Morse says. But the geographic scope is expanding.

“I've been on the job for 19 years and I've seen a couple of things happen,” he says. “We've seen a change in the locations in which farmers are growing their oysters. This means outside of the Damariscotta, but also in areas that, 15 years ago, people might not have given a second thought, but are turning out to be fine oyster-producing sites, like Casco Bay, the Bagaduce River, Frenchman Bay. So the type of site has broadened. The other big change is the type of person who's growing oysters.”

It used to be those DMC students. “Now, you see more people from commercial fishing, and people with no connection to marine industries at all, because maybe they've tasted Maine oysters and became enamored of how oysters are grown and the oyster farming lifestyle.”


Mook was one of those students from the Darling Marine Center. He got a job at a commercial shellfish hatchery in Muscongus Bay, then started his own business. He eventually focused on oysters because of their high per-unit value and burgeoning demand both for market-size oysters and for oyster seed.

Today, he considers his a small but rapidly growing business. Employee numbers have grown from four in 2010 to 24 year-round and seasonal today. Finding staff isn't easy.

“We've been creating a lot of jobs. And they're good jobs” with a education level from high school to doctorate level, he says. Most hires come from out-of-state. “We're actively involved in pushing for more aquaculture training programs for all skill levels,” he adds.

His hatchery produces 120 million oyster seeds a year. More than 90% are sold to other growers throughout the mid-Atlantic and Northeast. He grows the rest on his approximately 40 acres of leases on the Damariscotta, grading and thinning them throughout their growing cycle. Mook declines to cite harvest numbers, but says he deploys 5,000 OysterGro cages, each holding 1,200 oysters at the final thinning before harvest. He began testing the system in 2010, perfected protocols and expects to reach full capacity this year. The system has already doubled weekly output.

The innovative cages have floats that allow them to hang below the water's surface, which provides for optimal food levels and water flow. To control fouling, each cage must be periodically flipped above the surface to dry out.

“It's labor-intensive and you need a small army of strong, young people to do this,” says Mook. “So there was a strong incentive for us to mechanize this process.” Mook came up with a tractor-like “contraption” — two small vessels, linked by a rigid expanse that's fitted with a hydraulically operated device that flips the cages.

The OysterGro system was developed by Bouctouche Bay Industries Ltd. in Bouctouche, New Brunswick. OysterGro allows Mook to expand operations from seasonal to year-round, because he can tow the cages to ice-free sites.

His oysters are sold as four brands. There's Wiley Point and Pemaquid Point, which are distributed by J.P.'s Shellfish in Eliot; Mookie Blues, sold by Island Creek Oysters in Duxbury, Mass., and Fisherman's Catch of Damariscotta; and Moondancers, sold through a sales agent shared with Cape Cod Oyster Co. in Barnstable, Mass., and by Damariscotta River Distribution/Riverbottom Raw Bar in Newcastle.

He's also ramped up production of microalgae, used as oyster feed. In recent years, Mook developed a fermentation technique, using sugar, to replace the typical photosynthesis method that requires more space to allow light to reach all cells in the culture. Fermentation provides energy needed throughout the culture, thus allowing for denser growth in smaller spaces. That's increased feed production 25-fold. Currently, his team is working to further optimize the nutrient medium, with financing from an MTI seed grant.

Under construction now is a facility, expected to be operational this winter, for a recirculating holding system. The idea is to create optimal conditions (temperature, salinity, pH, and food levels) for reducing levels and ensuring control of a human pathogen called Vibrio parahaemolyticus in market oysters. He also plans to develop part of the existing hatchery building for a pilot hatchery for other species, as seed for customers and to diversify his main crop.

Climate change

Perhaps as significantly, Mook and his team are studying the impact of climate change on oysters.

He first noticed ocean acidification impacts on larval production in 2009, when fertilized eggs periodically showed poor survival, deformities or stalled growth.

“If you're producing millions and millions of seed to deliver to customers and for your own business, that's disruptive,” he says.

Mook solved the problem, and even got bigger yields, by monitoring and modifying the chemistry of seawater pumped into the hatchery. But the experience “opened our eyes to changes that have occurred to seawater chemistry over the 32 years we've been in business,” he says. That led, in 2013, to teaming up with University of New Hampshire oceanographer Joe Salisbury on a long-term project to understand how seawater chemistry continues to change and how it impacts calcification, growth and survival of juveniles. The project deploys sophisticated sensors developed with funding from NOAA's Ocean Acidification Program and Integrated Ocean Observing Systems Sensors. So far, they haven't seen any changes in growth or survival rates, although he considers it likely that ocean acidification is causing reduced calcification rates.

“It's important to not be reacting to a crisis when it occurs, but to be able to understand when that crisis will occur and have strategies in place to cope,” he says.

Meanwhile, Mook anticipates continued growth for his business and the industry in general.

“What I think about is whether per capita consumption has scope for continued growth,” he says. “I believe it does, because people like to eat oysters and we're still a long way from per capita consumption levels in the U.S. back in the late 1800s and early 1900s, or current per capita consumption rates in Europe.”

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