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Offshore aquaculture project underway in Hawaii

An aquaculture company experiments with unanchored fish-farm cages set adrift on eddies near Hawaii.

Kampachi Farms, an aquaculture company based in Hawaii, is embarking on one of the most ambitious aquaculture projects in the United States. Their 2011 Velella Research Project involves an unanchored cage of fish that freely moves with currents and winds in water over two miles deep and up to 150 miles off the Hawaiian coast.

The goal is to farm fish as sustainably as possible — namely, moving cages offshore to reduce many of the environmental impacts of aquaculture. The cost of anchoring cages in waters that are extremely deep, and the need to significantly scale the production of fish without impacting local water quality and seafloor biodiversity, make drifting cages offshore an attractive alternative to traditional near-shore cages.

The system is the first American project to raise fish in cages not tethered to the ocean bottom. This is possible because of Pacific Ocean currents form large eddies behind the Hawaiian Islands. When the cages are released off-shore, they spiral behind the island in a relatively predictable region, even cycling back to near-shore zones. It’s called Velella because that is the scientific name of a harmless free-floating marine organism related to the Portuguese man-o-war.

The Velella Project addresses two of the major environmental critiques of cage culture: negatively impacting the seafloor below cages, and infecting local fish populations with disease.

A free-floating cage adrift off the coast of Hawaii. Image Credit: Kampachi Farms

The open ocean has very low biodiversity; it’s the equivalent of a terrestrial desert, making it an ecologically safe place to farm fish, keeping cage remains far from highly diverse near-shore coral reefs. Additionally, the incredibly deep water means that the cages will have virtually no impact on the ocean floor; currents and organisms will disperse and consume cage waste long before it can reach the bottom. This design makes the Velella system the most ambitious fish farming system yet developed within American waters.

Satellite image showing how the cages drift in the eddies. Image Credit: Kampachi Farms

The offshore marine waters are under federal jurisdiction and, as such, have no clear rules for permitting of aquaculture operations. However, they include a vast area that has potential for producing seafood in a way that will conflict far less with other human uses of the area than is true for near-shore cages and pens.

The main issue with sustainability of these systems is whether they can be economically viable, given the high costs of infrastructure, as well as transportation of feed and fish between the cages and land-based operations. Velella addresses this with a ship that remains attached to the cage to perform routine operations, thus reducing the need for regular movement between land and sea-based locations. They also seem to have reduced the capital cost and probably improved the regulatory environment by not permanently attaching cages to the seafloor. Whether the company can be profitable remains to be seen, but overall this experiment is a promising idea for new, low-impact aquaculture systems in offshore areas.

Bottom line: Kampachi Farms is experimenting with unanchored fish-farm cages that float in eddies off the coast of Hawaii. The goal of the 2011 experiment — the Velella Research Project — is to reduce the environmental impacts of aquaculture.

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