Ku‘uipo McCarty and her assistant Ikaika Velez were grinning ear-to-ear on Monday as they pulled mesh cylinders full of Pacific oysters out of the 800-year-old Moli‘i Fishpond at Kualoa Ranch.

The oysters, which were grown in the nutrient-rich ancient Hawaiian fishpond for about seven months, hit the local market that afternoon as the first state-certified commercial harvest in decades. Kualoa Ranch, which has been test-growing oysters for about four years, obtained the permit on Feb. 20 allowing them to sell oysters in their visitor center, at farmers markets, and to local restaurants and retailers.

They hope to play a role in turning oyster farming into a multimillion-dollar industry for Hawaii, which annually imports about 400,000 oysters from the mainland and Asia.

"We pulled 500 oysters from the pond this morning," said McCarty, the 27-year ranch employee who is spearheading its oyster program. "It’s a very exciting day."

Growing oysters, which are endemic to Hawaii, has long been seen as a business with great potential for the state. Hawaii’s Department of Health, seeing an increased interest from farmers, recently recertified its lab that is responsible for making sure shellfish growers meet U.S. Food and Drug Administration requirements for the highly regulated industry.

"We’ve got a newly created program and the future of it looks very bright," said the department’s Peter Oshiro. "I think locally grown Hawaiian oysters will be a huge draw. I’m sure that all of our local restaurants have been waiting for a product of this kind."

Maria Haws, director of the Pacific Aquaculture and Coastal Resources Center at the University of Hawaii at Hilo, said she expects that with regulatory infrastructure in place, Hawaii could see a more than $20-million-a-year shellfish industry emerge in the next five to 10 years.

"I think my estimate may be conservative since that’s about what Rhode Island does," Haws added. "The U.S. shellfish industry is over $1 billion and in Washington state alone it produces about $150 million."

With its permitting in place, Kualoa Ranch is off and running. John Morgan, the ranch’s president, said oyster farming is potentially the most significant agricultural venture for Kualoa since 2011 when it started retailing its grass-fed Kualoa beef online and at its visitor center.

The ranch, which occupies 4,000 acres along Oahu’s northeastern coast, has been involved in the cattle business since the 1870s. Morgan is a descendant of Dr. Gerrit Judd, who bought the first 622 acres of the ranch from King Kamehameha III in 1850.

"Our goal is to increase our product line and grow a wide variety of things," Morgan said. "It’s our belief that the land should be productive and sustainable. It’s tough to make money in a Hawaiian fishpond with the traditional fish like native green-striped mullet and/or awa. This is an adaptive reuse of a Hawaiian fishpond that adds to Hawaii’s food security."

David Morgan, John’s brother and the ranch’s agricultural director, said oysters are expected to make a significant contribution to the ranch’s agricultural diversity.

"We’ve got about 28,000 oysters growing out there and if we could get it, we’d put more seed out today," he said, adding that the mollusks will supplement the ranch’s farming of produce, saltwater shrimp, tilapia and Malaysian prawns.

While Kualoa Ranch’s oyster farm is the first to be certified by the state’s new program, Haws said other farmers are not far behind. She also expects similar ventures will be attractive to Hawaii entrepreneurs with access to seawater, through a well, a fishpond, or an offshore lease.

"People in Hawaii have objected to offshore fish farming, but oysters don’t pollute," Haws said. "Most of the water pollution in Hawaii is nutrient-rich and oysters help clean that up."

Since oysters are a part of a healthy ecosystem, Haws said, the Nature Conservancy and state agencies around the country are spending money to get them into the water.

"The beauty in this case is that they would help clean up the environment while producing a crop," she said.

Haws and her students are closely involved with the burgeoning oyster-farming movement in Hawaii, which is already the oyster hatchery capital of the U.S. since the waters here are less acidic than on the mainland.

"Farming oysters would be a natural extension of our hatcheries businesses," she said. "We’re still doing research, but the Pacific oysters grow well and we think we could also grow the smaller, endemic Hawaiian oysters."

Haws’ students nursed the Pacific oyster seeds that Kualoa planted in its fishpond. They’ve also done oyster farming trials with the operators of the He‘eia fishpond in Kaneohe.

"The research was really promising. Because of our climate, we could bring the oysters to market in about nine months, where it would have taken three or four years on the mainland," she said, adding that Keawanui Fishpond in Molokai also has oysters in the water and is finishing its water sampling.

Likewise, Sunrise Capitol Inc., which does business as Kauai Shrimp, is considering growing Japanese Kuma­moto oysters, said Mike Turner, the company’s director of sales and marketing.

"There are a lot of moving parts, but we think that we could produce these oysters in about a year to a year and a half," Turner said. "We’ve already had tremendous success farming clams and we think oysters are certainly something that we could do, too."

Last May, Sunrise Capitol was awarded the first state permit to farm clams in more than 20 years, he said.

"The clams have been excellent," Turner said. "We don’t have nearly enough to meet the demand. Right now, we’re at about 150 pounds a week in production, but we hope to get to 1,000 pounds per week."

Turner said clams and oysters, which feed off shrimp-farming byproducts, are compatible businesses.

"There’s no question that if we could produce more product using the same energy and the same feed, we would be even more successful," he said. "We think basically all of the shellfish that we produce will be consumed in the state."

Chef Chai Chaowasaree, owner and chef of Singha Thai Cuisine in Waikiki and Chef Chai at Pacifica Honolulu, agrees that demand in Hawaii is strong for fresh, tasty shellfish.

"We sell a lot of oysters," Chaowasaree said. "I’m looking forward to trying a Hawaii-grown oyster. If they are good, I think they will be very popular. Tourists and locals always like anything from Hawaii since it’s fresher and better for our environment."

Tourists Abbie Vee and Cheri Squires, of Santa Clara, Calif., raved about Kualoa Ranch’s oysters, which they sampled raw on Monday.

"They don’t need any condiments," said Vee, who went back for seconds. "They taste just like the ocean."

Squires, who ordinarly dislikes raw oysters, said she enjoyed Kualoa’s oysters.

"Your oysters are going to be very popular," she said. "They were way better than the ones that I’ve tried from the farms near San Francisco Bay."