Ocean farming has had a troubled past, but it's moving forward quickly as technology improves.
The state Board of Land and Natural Resources just approved a Conservation District Use Permit for the latest and largest ocean aquaculture venture.
(Image: Artist's rendering of the Hawaii Ocean Technology fish farms, approved Friday by the land board. Credit: Hawaii Ocean Technology LLC)
Already in Hawai'i, you can buy moi from open ocean farms off south O'ahu. It's grown by Grove Farm Fish & Poi, and is served at fine restaurants across the state. Grove Farm Fish & Poi is planning to roughly quadruple its production in Mamala Bay. An early slideshow of predecessor company Cates International is here.
And you can get kahala or Kona Kampachi or Hawaiian yellowtail from Kona Blue Water Farms' ocean cages in waters deeper than 200 feet off Kona on the Big Island. See here.
Kona Blue uses a technology called Sea Station, which creates a flying-saucer-looking netted structure that can be raised and lowered in the water column. But the firm cites transportation costs to Mainland markets for a proposal to cut its production by 40 percent and look to Mexico for future growth.
There's another proposal by a venture called Indigo Seafood to put moi cages off the Big Island.
The most innovative new proposal is Hawaii Ocean Technology's Ahi Sphere project, which would be the largest ocean aquaculture project in the Islands to date. The land board approved the CDUA for the project Friday.
The company this year released its final environmental impact statement for its proposal to grow tuna in a fleet of twelve 160-foot-diameter “ocean spheres” which actually look more like geodesic domes than spheres.
“The company proposes to grow out the tuna to market size in offshore submerged cages, segregated by species, that are self-powered un-tethered 54m diameter 'Oceanspheres.' The proposed ocean lease site is a one square kilometer (247-acre) site, 1,320-feet deep, located 2.6 nautical-miles offshore Malae Point, North Kohala. Twelve Oceanspheres will be deployed incrementally over four years, culminating with an annual production capacity of 6,000 tons,” the report says.
It will be managed out of Kawaihae Harbor, and boats will be on site daily to handle feeding, harvesting and other duties. The baby fish—yellowfin and bigeye tuna-- will be grown at a University of Hawai'i facility.
Critics of sea farming ventures warn of disease among tightly-packed fish that could spread to wild populations. Of pollution from the concentrations of fish scat and uneaten fish food. Of attracting sharks. Of the loss of use of portions of the ocean.
The EIS addresses these issues at some length, but briefly, it argues:
The project will work with the Hawaii Institute of Marine Biology to monitor and manage the project for disease control. The site has been selected for its strong currents, which will very quickly dilute and sweep away organic matter. The cages have powerful netting that should be impenetrable to sharks. And it says the area selected is not an actively fished zone—it is beyond the ono trolling grounds and deeper than most bottomfish grounds. Boaters will be permitted to transit through the lease area, as long as they stay 100 feet from the spheres, which will be marked with buoys.
The spheres will have GPS capability, will be self-propelled, and capable of maintaining position without being anchored to the sea floor.
© Jan TenBruggencate 2009