A closer look at Humboldt Bay oysters
6/15/11
Residents and out-of-town visitors will consume more than 100,000 oysters today at the 21st annual Oyster Festival held on the Arcata Plaza, a fitting celebration for a region that has become a leader in oyster production for the state.
According to Tony Smithers, executive director of the Humboldt County Convention and Visitors Bureau, the festival has been recognized as the seventh-best food festival in the United States.
As festival-goers bite into freshly grilled Pacific oysters slathered in barbecue sauce or slurp back Kumamoto oyster shooters doused in lime, they may want to stop and consider where all of those oysters came from.
The history of oyster harvesting in the bay has seen its fair share of ups and downs. Prior to European settlement, Native Americans harvested the region's native oyster, commonly referred to as the Olympia oyster. In the late 1850s, the Olympia oyster's natural population was devastated due to over- harvesting.
Settlers from the East Coast looking for gold set up commercial oyster fisheries that rapidly consumed the slow-growing Olympia oyster stock, according to a report by the Department of Fish and Game.
Humboldt Bay didn't come back onto the map as a major oyster producer until the 1950s, when Pacific oyster seed was first brought to Humboldt Bay. Shortly thereafter, Kumamoto oyster seed was introduced.
A few years back, Coast Seafoods -- the largest oyster farming company in Humboldt Bay with about 50 employees -- underwent a rigorous permitting process that completely restructured the way the company harvested oysters. The company went from dredging, or hydraulically harvesting oysters off of the bay bottom, to suspending its oysters above the bay bottom on long lines strung between poles or on racks in bags.
Coast Seafoods General Manager Greg Dale said his company farms both the Pacific oyster and the Kumamoto oyster -- around 60,000 gallons a season, with each gallon containing 100 to 200 oysters.
Nowadays, farming facilities like Coast Seafoods receive Pacific and Kumamoto oyster seed from hatcheries that specialize in remote setting.
At these hatcheries, oyster larvae are placed in tanks that contain shell, referred to as mother shell or clutch, and sea water. The larvae metamorphose, no longer able to float in the water's currents, and settle onto the clutch, where they will remain for the rest of their lives.
Between 20 and 40 larvae will set onto one mother shell, but usually only half of those will grow into market-sized oysters.
Once the spat is attached to the clutch, it is then transferred to the oyster farmer where the mother shell is placed into large, long bags and piled up in an intertidal nursery area of the bay to allow the spat to grow and harden.
After the spats have reached about 3 to 4 millimeters in size, they are brought back to the plant where the mother shell is strung at intervals onto long, yellow lines. Those lines, a methodology referred to as long line culture, are then strung between a series of notched PVC pipes that are stuck into the bottom of the bay. In this way, the growing oysters are held off the bottom of the bay and away from predators.
According to Dale, oyster farming is anything but easy.
”It's tough work,” Dale said. “Our guys are out here working every day.”
Coast Seafoods also uses the rack-and-bag method to grow oysters. This technique is the primary means of farming for Humboldt Bay Oyster Co., according to owner Todd Van Herpe.
Herpe's company, which will supply roughly 18,000 oysters to today's festival, uses the rack-and-bag method of oyster farming because it produces single oysters that are not clumped together.
Herpe, who has been involved in the oyster industry for 19 years and has owned Humboldt Bay Oyster Co. since 2002, said he farms individually grown oysters because they are thought to be more aesthetically pleasing than those that are grouped together.
Typically, individual oysters are sold on the half shell in restaurants or for barbecuing.
The rack-and-bag method uses clutchless seed that is produced at a hatchery when larvae are set on finely crushed -- instead of whole -- mother shell. Each piece of shell is the size of the larvae. Because the seed is much smaller than the spat that is grouped onto the mother shell used in long line farming, it is grown in racks lined with fine mesh to prevent it from dispersing into the ocean.
The length of the growing process varies by oyster, but is time intensive -- regardless of which farming method is employed.
The Pacific oyster takes about one to one and a half years to grow, while the Kumamoto can take two to three years.
For Herpe, farming oysters is like being on a big conveyor belt, because they require constant care all year round.
”The concept is to keep feeding the conveyor belt,” he said. “If we aren't constantly taking care of it, nothing will come out on the other end.”
Herpe adds, it's all worth it. Not only does he enjoy the work, but he also enjoys the positive environmental effects the oysters have on the bay.
”Oysters serve a beneficial ecological purpose by filtering water (as much as 50 gallons a day per oyster), battling eutrophication and providing structure to the bay,” Herpe said.
According to Dale, not only are the oysters good for the environment, they are also just plain good.
Dale believes that Humboldt Bay produces some of the better oysters in the United States. When it comes to the Kumamoto, it may even be safe to say that Humboldt Bay produces the best.
”The Kumamotos are highly prized -- they don't grow everywhere,” Dale said. “They have Goldilocks' syndrome. That means they don't like it too hot or too cold, and for whatever reason Humboldt Bay works for them.”
Other major oyster farmers in Humboldt Bay are North Bay Shellfish and Aqua Rodeo Farms.
