Kona Blue Water Farms, an operator of open-ocean fish farms off the Kona Coast, said it had raised $2.6 million to expand its Kona operations.

The company also said it is seeking further funding to help with possible expansion with sites in the Sea of Cortez in Mexico.

Kona Blue said the money was raised from existing investors, a group that includes Kealia Makai Holdings. The new round of funding comes as the aquaculture operator enjoys strong sales growth for its Kona Kampachi fish. It said between January and December 2007, sales tripled.

The company raises and sells fish under the Kona Kampachi name, a fish that's know as kahala or amberjack in the wild. Kona Blue promotes the fish as being raised without significant environmental impact and as an excellent source of Omega-3 fatty acids with no detectable mercury or other contaminants.

Spokeswoman Kelly Coleman said the new financing would be used to expand the Kona farm's existing cage infrastructure. The company is seeking government approvals to exchange its eight cages in water over 200 feet deep with larger ones. It wants to replace the existing pens that average about 3,000 cubic meters with those that are about 6,200 cubic meters.

Last month about 1,500 of Kona Blue Water Farms' fish were accidentally released from an offshore cage.

The fish escaped after a diver failed to lock one of the fish pens, said Neil Sims, president of Kona Blue. The fish are native to Hawaiian waters and pose minimal environmental risk, he said. The escaped fish, which weighed about 2 pounds, were valued at more than $10,000. Kona Blue said it implemented new procedures to prevent a similar incident.

Kona Blue last year moved its headquarters to San Francisco to put executives closer to major customers and potential investors. The company said it is the first integrated hatchery and open-ocean aquaculture operation in the United States.