Aquaculture Musseling In on Wild Mollusks : A New Shell Game Down on the Farm and Under the Water

CARLSBAD —  Down on Dick Glenn’s farm, the animals aren’t kept in pens.

Heck, they’re not going anywhere. They move very slowly, and their pastures are all under water.

Glenn is the president and owner of Seafarms West, Southern California’s only mussel and oyster farm. He and a partner launched the venture 18 months ago in the shallow waters of Agua Hedionda lagoon, and Seafarms West now harvests thousands of the tasty little mollusks every week. Many of them are served in some of the area’s top restaurants.

European Technology

Most of the technology and some of the equipment that Glenn uses for raising shellfish were developed in Europe. But local water conditions and the climate make shellfish farming here a unique experience--for the mussels and oysters as well as for Glenn.

It seems to suit them all. Glenn, 47, grew up in nearby Ontario, and has the bleached hair and tanned look of someone with a lifelong affinity for the beach.

After earning a Ph.D. in biology from UC Santa Barbara, he taught at San Diego State University, Southwestern College in Chula Vista and National University in San Diego. “But my interests--diving, boating, surfing--have always centered around the ocean,” he said, “and I kept looking for a way to get involved with it in my career, too.”

Five years ago he and a partner made test plantings of oysters in Agua Hedionda lagoon. It took them a year to conclude that the shellfish could be grown there, and another to negotiate a lease of five acres from the lagoon’s owner, the San Diego Gas and Electric Company.

Short Growth Cycle

The first commercial plantings of oysters were made in June, 1985, and by the end of that year Seafarms West was harvesting its first crop. “One of the things that makes this place unique . . . is that we can grow oysters to marketable size in eight to ten months,” said Glenn. “In France, it takes two to three years.

“Almost every other place where oysters are grown (including the states of Maine and Washington), the water gets considerably colder in the winter, and the oysters stop growing. Here, the water isn’t all that warm--60 to 70 degrees--but it never gets all that cold, either. That’s the key. Our shellfish grow continuously.”

Buys ‘Seed’ Oysters

Glenn (who recently purchased his partner’s interest and is now sole owner of the farm) buys “seed” oysters by the thousands from an oyster farm located on Northern California’s Humboldt Bay. The young oysters, only a half-inch in diameter, are put in sacks made of heavy plastic mesh, and the sacks are then laid on metal racks on the bottom of Agua Hedionda lagoon. At high tide the oysters are about eight feet below the surface; at low tide they’re exposed to the air.

“They’re submerged about 80-90% of the time, but being exposed (regularly) to the air changes their physiology,” Glenn explained. “Their shells grow thicker and stronger, which makes them easier to shuck. And their meat gets fatter and more plump, too--it’s as if they’re storing more nutrients to sustain them if they have to remain (exposed).”

Glenn said his farm currently produces 2,500-3,500 oysters a week, adding that he’ll soon be harvesting 7,000-9,000 a week. And although he started with the idea that Seafarms West would be an oyster farm, mussels are turning out to be his main product. “We found we could grow mussels pretty easily, and the demand is stronger than I expected.

“Nationwide, the consumption of mussels is growing at something like 15% a year. But most people on the West Coast don’t think of mussels as food--not yet, anyway. If they think of mussels at all, they think of them as fish bait.”

Tender Bay Mussels

The mussels raised by Seafarms West are bay mussels, which are more tender than the familiar California mussels found in huge colonies on coastal rocks and cliffs. But bay mussels are also native to this area, Glenn said. “We’re just giving them a better way to grow.”

Most of the farm’s young “seed” mussels are culled from the lagoon by Seafarms West employees--including Glenn’s 25-year-old son Paul--who use snorkels, face masks and wet suits to do the work. The young mussels, less than an inch long, are then put into eight-foot-long tubular “socks” made of plastic mesh, and the socks are suspended at regular intervals from long lines that float on the lagoon’s surface.

“They just hang there, and the currents bring them their food. Both mussels and oysters are filter feeders--they suck plankton out of the water,” Glenn said.

“We’re getting marketable mussels--two to 2 1/2 inches long--in only eight or nine months. That also makes this place unique, because in Spain, where they grow more mussels than anywhere else in the world, the fastest growing time is 15 months. On the northeastern coast of the United States, where the water is even colder, it sometimes takes more than three years for mussels to reach marketable size.”

Glenn didn’t pick Agua Hedionda lagoon because he knew it would be a rich mollusk-producing area, though. He did like the fact that it was protected from turbulent surf. And, because the lagoon is a source of cooling water for SDG&E;’s Encina power plant, the utility makes certain that the mouth of the waterway is always open, which in turn insures that fresh water and nutrients flow in regularly with the tides.

One Available Lagoon

He chose Agua Hedionda, Glenn explained wryly, primarily because it was the only lagoon in Southern California that was available. It’s owned by SDG&E;, whereas most bays and lagoons are owned or protected from commercial development by state and federal agencies. And although yacht harbors are possible alternatives, “in a yacht harbor there are a number of potential water quality problems--a break in a sewage line, an oil spill, a ship illegally pumping its bilges--which would create major headaches” for someone trying to raise shellfish, Glenn said.

Even in Agua Hedionda, sewage pollution is a major concern. Heavy rains cause the bacteria level in the lagoon to rise, but the level usually returns to normal within one tidal change.

A more serious problem developed last summer, when a nearby sewage pump station broke down and spilled sewage into the lagoon. “At one point, the bacteria count jumped to 100 times what is acceptable. But it returned to normal in three days. We just stopped harvesting for about a week, until the animals were in good shape,” Glenn said.

To keep track of the lagoon’s water quality, Glenn takes water samples every two weeks, which are analyzed by a local lab certified by the sanitary engineering branch of the state department of health services. As an additional safety measure, newly harvested mollusks are put in large trays with sterilized water flowing through them. Glenn said the oysters and mussels “might sit in the trays for one night or a week,” filtering the sterilized water through their systems and washing out sand and other impurities.

Glenn figures he has invested more than $100,000 in Seafarms West and is just now reaching the break-even point. Most of his customers are local, but that, too, is changing. Fish wholesalers in Los Angeles and San Francisco now buy shellfish regularly from Seafarms West, and Glenn recently sent 250 pounds of mussels to Chicago.

His largest buyer, though, is Leong-Kuba Sea Products, a San Diego fish wholesaler that buys about 80% of the total production of Seafarms West. “Their products are competitively priced,” said Glen Kuba, president of Leong-Kuba, adding that the oysters and mussels from Seafarms West are generally fresher than those he obtains from the East Coast.

Glenn, who conceded he used to have doubts about whether or not his shellfish farm would succeed, is now convinced he can supply regional customers with fresh mollusks in large-enough quantities to make a profit. Mussels and oysters shipped from the East Coast are a minimum of two or three days old by the time they arrive in San Diego, whereas “ours are on somebody’s plate 24 hours after they leave our farm,” he noted.

For livestock that doesn’t move very much, that’s pretty fast.

wheelbarrow and handful