If a message in a bottle or a Portuguese man-of-war can drift for months on ocean currents, why not cages of "farm-raised" fish?

A Hawaii aquaculture company wants to test the idea.

Kona Blue Water Farms has applied for a permit to determine whether it would be possible to grow young amberjack to harvest size over 10 months in submerged cages tethered to surface buoys drifting freely on a circular ocean current off the Big Island.

Neil Sims, Kona Blue president, believes the idea could eliminate ecosystem impacts of near-shore ocean aquaculture farms, produce healthier fish and provide abundant room for industry growth.

"This is one of the next steps that we have to do to grow more fish in an environmentally responsible manner," he said. "The whole world could benefit from this."

Presently, two ocean-based fish farms operate in Hawaii. One was started by Kona Blue raising amberjack trademarked as Kona Kam­pa­chi off the Big Island, though production has been stalled for more than a year because of high costs and inefficient cage configurations. The other is Huki­lau Foods, which continues to produce moi off Oahu but is in bankruptcy after trouble expanding a shore-based hatchery.

A third company, Hawaii Oceanic Technology, is pursuing a plan to raise bigeye and yellowfin ahi off the Big Island.

The present mariculture models in Hawaii are all similar, with relatively stationary submerged cages in state waters within three miles of shore. This setup has drawn criticism from environmental groups claiming that concentrations of fish waste and uneaten food negatively affect near-shore ecosystems.

Industry operators say tests show no significant negative environmental impacts. But Kona Blue said in its permit application that allowing cages to float freely in more pristine waters would improve water circulation, reduce fish disease and better disperse waste.

The company has applied for a permit from the National Marine Fisheries Service to conduct the test in federal waters roughly five to 150 miles from shore.

According to the application and Kona Blue, major currents in the Pacific Ocean hit the Big Island to create a smaller circular countercurrent, or eddy. This eddy is fairly consistent with a 60- to 90-mile diameter off the Big Island’s western face.

"We think it’s a way to maintain an untethered pen in close proximity to the Big Island," Sims said.

To study the feasibility of drifting mariculture, Kona Blue proposes stocking two cages each with 3,000 hatchery-raised fingerlings and using an 80-foot sailing ship to put the cages in a controlled drift following the eddy while the fish reach harvest size over 10 months.

Buoys above the cages would be outfitted with global positioning system transmitters and lights, and counterbalanced with weights below the cages. A feeding tube would be connected to the ship.

Kona Blue has dubbed its proposed test the "Velella Proj­ect." Velella is a scientific name for a group of organisms, including Portuguese men-of-war, carried by currents on the ocean surface. The test would help prove whether cage arrays with self-feeding mechanisms could float freely.

Kona Blue has produced a draft environmental assessment, and the Fisheries Service is considering whether to issue a permit based on the assessment and considerable public comments made about it. The deadline for comments has passed.

Some opponents of open-ocean aquaculture have questioned the applicability of the permit Kona Blue is seeking. Technically, Kona Blue applied for a fishing permit that categorizes the cages as a type of fishing gear.

Food & Water Watch, a Washington, D.C.-based organization and critic of open-ocean aquaculture, fears the test will open the door to commercial fish farms in federal waters through the Fisheries Service, which is part of the National Oceanic and Atmospheric Administration.

"NOAA is putting ocean fish farming cages in the same category as rods and reels and fishing nets, so the agency can claim it has authority to issue a permit for this new ‘gear type,’" Weno­nah Hau­ter, executive director of Food & Water Watch, said in a statement. "It’s outrageous that NOAA is equating this dangerous, large-scale polluting method of farming fish with fishing."

According to the Fisheries Service, commercial aquaculture of a species managed under a federal fishery management plan in federal waters is considered fishing under federal law.

Sims said the permit, if approved, is limited to the one-time trial. "This is not a commercial permit," he said. "This is a research permit."

While doing a preliminary test, Kona Blue encountered a major mishap. The company conducted a test tow last month with two empty cages behind the 80-foot schooner, the SV Machias. Sims said the combination of a gale and rough seas snapped a rigging line that couldn’t be reattached.

The crew attempted to scuttle the cages, but one cage didn’t sink. "It’s still on the surface somewhere," Sims said.

Despite the setback, Sims said the research remains important and could improve open-ocean aquaculture. "We still believe this concept needs to be tested," he said.