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By COLIN M. STEWART
Hawaii Island is poised to become a major player in the U.S. oyster industry, as growers on the mainland wrestle with the effects of climate change.
Around 2007, oyster hatcheries along the West Coast were significantly impacted by a disturbing trend.
“Oyster larvae hatcheries were seeing large die-offs during the spring and summer,” said Dave Nisbet, owner of Goose Point Oysters of Washington state’s Willapa Bay. “Oceanographers were seeing increased acidification of the West Coast’s ocean water during the spring and summer months, and the pH shift was just enough to cause larvae to die.”
The immature larvae require a very specific pH level to be able to pull calcium from the water to build their shells, he said, and increased levels of carbon dioxide in the world’s oceans has begun to affect that process.
“You’re not going to get a debate from me on climate change,” he said. “It’s here. It’s happening. I’m seeing it.”
The effect is happening around the world, according to Maria Haws, director of the University of Hawaii at Hilo Pacific Aquaculture and Coastal Resources Center in Keaukaha, which is working with growers to explore building a shellfish industry in Hawaiian waters, which are experiencing acidification to a lesser degree.
“The impacts are much more noticeable in the Pacific Northwest. … It’s affecting other species too, it’s just that they noticed it with oysters first,” she said. “They’re like the canary in the coalmine.”
It is believed that the West Coast feels the brunt of the acidification process because it experiences an upwelling of deeper, more acidified water onto the continental shelf during the spring and summer months, she said.
Nisbet’s business, which supplies buyers with billions of oysters every year, was beginning to be impacted by independent hatcheries’ inability to produce enough oyster seed, or oysters in their early growth stages. So, he turned to Hawaii’s warmer, cleaner waters and year-round shellfish breeding season.
In 2009, Nisbet partnered with Haws and the Pacific Aquaculture and Coastal Resources Center in Keaukaha to look into growing oyster seed in Hawaii. The results were so promising that in 2012 he launched Hawaiian Shellfish LLC in Hawaiian Paradise Park — producing enough seed to supply his entire business back in Washington, while selling surplus seed to other growers.
Employing six people — including three Hawaii residents with degrees from UH in aquaculture — Hawaiian Shellfish pumps about 60,000 gallons of water from a deepwater saltwater well along the Keaau coast into 12 large tanks that provide perfect growing conditions.
While the energy to pump the water 24 hours a day is a major expense, Hawaii’s warmer water means he doesn’t have to spend what hatcheries on the mainland do to heat it, Nisbet said.
“The requirement for oyster larvae is water around 75 degrees, and in the West Coast hatcheries in the springtime, we would use oil-fired boilers to bring the water to that temperature because the water runs in the 50s,” he said. “We basically have that here all year, and that’s been a big plus for us.”
Shipping the larvae back to the mainland to complete their growth cycle is also a relatively cheap process, as the oyster seed is very small and can be shipped easily.
“There are about 50 million larvae in a ball the size of tennis ball,” he said. “Shipping isn’t an issue.”
Hawaiian Shellfish, Nisbet said, has been such a success that he’s already looking at the possibility of expanding and raising other varieties of oysters.
“We’ll probably expand a little bit. We’re taking care of all our needs right now, and that was the main purpose of this. We’re pretty happy with how the operations have been going,” he said.
Stories like Nisbet’s are music to Haws’ ears. As director of the Pacific Aquaculture and Coastal Resources Center, she is charged with overseeing research to help clear the way for farmers to build a shellfish industry in Hawaii.
Located in an old water sewage treatment plant along Kalanianaole Avenue, the center provides large tanks that serve as test grounds for experimental cultures. UH students and faculty help devise processes for breeding, feeding and maintaining thriving colonies of various varieties of fish.
With help from the aquaculture center, the pioneers of Hawaii’s shellfish industry have been a total of four businesses, including Nisbet’s, which primarily produce oyster seed for shipping to the mainland. Two are located in Kona and work in concert with the Natural Energy Laboratory of Hawaii Authority. A third operates on Molokai, Haws said.
The next step would be for businesses to raise oysters and other bivalves, such as clams, to full maturity in Hawaii’s open waters, Haws said. But before that can happen, the state Department of Health must complete an exhaustive study of water quality in various areas farmers have identified for oyster cultivation, to generate what is known as a “growing area classification,” to ensure that any oysters grown to maturity in Hawaii’s waters would be safe to eat.
Such a study has been under way for about a year, Haws said, and she expects results in about six months.
“The DOH has really been great. They took a big step in looking into our growing area classification,” Haws said.
If everything goes as expected, that could open the door to restaurants and sellers offering Hawaii-grown oysters to in-state consumers. Further permitting would allow exportation of Hawaii shellfish, which could one day lead to them being offered as premium specialties at mainland seafood restaurants.
But Hawaii has a long way to go just to sustain its own hunger for oysters.
“We’re not going to be able to supply our own need for a while. We import close to 400,000 oysters every month in Hawaii. That’s a heck of a lot of oysters,” Haws said.
One day soon, she added, “we’ll end up like the Northwest. Restaurants there, they have lists to pick like six to 12 different varieties of oysters grown at different farms, each with their own unique flavor,” she said. “People here in Hawaii want to buy local products, so I see the growth being huge. … We’re right on the cusp.”
Pacific oysters thrive in Hawaii’s climate
By COLIN M. STEWART
Native to the Pacific coast of Asia, Pacific oysters, aka Crassostrea gigas, were introduced to North America and are currently the most cultured variety of oyster in the world.
They also happen to grow in Hawaii like gangbusters, according to researchers with the University of Hawaii at Hilo’s Pacific Aquaculture and Coastal Resources Center.
While Hawaiian waters currently can only be used to raise hatchling oysters to be sent to growers on the mainland, their potential is huge, said Maria Haws, the center’s new director.
“We’ve done some trials in Hawaiian fish ponds that can produce market size (between 3 and 4 inches) Pacific oysters in five to six months,” she said.
That’s a pretty amazing feat, when you consider that the same species takes two to three years to mature in waters in the Pacific Northwest, she said.
The difference is mainly due to the year-round warmer weather, which produces a constant supply of algae for the oysters to filter out of the water and eat. Meanwhile, Hawaiian waters have so far shown themselves to be less susceptible to the acidification process that has plagued oyster hatcheries along the West Coast in the last decade.
The Pacific Oyster is a filter feeder, Haws explained, sucking in nutrients from the water to feed itself and expelling clean water. In fact, she said, if enough oysters were grown in Hilo Bay, they could clarify the water, which is darkened by algal blooms brought on by water tainted by nutrients in agricultural runoff.
Currently, students and faculty with the aquaculture center are looking at using ancient Hawaiian fishponds as cultivation areas, because their walls provide protection from predators and rough waters.
“There are thousands of acres of fishponds available, and you don’t have the same permitting issues you might have elsewhere,” Haws said.
So what do you get when you combine Hawaii’s warm waters with just the right pH balance and plenty of sunlight-fed algae?
Carbohydrate-rich specimens of Pacific Oysters, with firm, white flesh. They’re referred to as “fat oysters” to those in the know, Haws said.
“They’re like wines. Every place you go will have a slightly different tasting oyster,” she said. “The oysters we grow here are great quality. They have a very sweet start and a salty finish — what is considered a superior oyster.”