Preference for Ahi or Bigeye Tuna is growing rapidly around the world, and Hawaii is no exception.  Ahi is second only to Bluefin Tuna in popularity, especially among sushi and sashimi fans.  The Blue Ocean Institute currently classifies Ahi as a species heavy fished and its global stock low and falling.  The eastern pacific fishers are catching them faster than they can reproduce. 

Enter Hawaii Oceanic Technology (HOT).  Last month the company received community support to build a 247 acre, 12 cage Ahi farm about three miles off Malae Point in North Kohala.    The company hopes to raise 6,000 annual tons of Bigeye and Yellowfin Tuna.   About ten percent will be sold locally under the King Ahi brand.   HOT will limit availability of King Ahi in local stores to protect the livelihood of local fishers.

The fish will be bred in tanks on land where they will stay until they weigh about five pounds.  Then they will be moved to very large submerged, self-powered “oceanspheres.”  The pens will travel with the ocean current untethered, using geostatic positioning technology.

Aquaculture is an appealing way to halt fish stock decline, but traditional methods have caused environmental and wild stock problems.  Some farms are disease prone, marine life has suffocated below farms, and farm escapees have harmed wild stock.  HOT’s novel approach should avoid these problems.  The secure kevlar net spheres will be 1,300 feet below the surface in open ocean where strong currents will keep the pens clean and the fish will have plenty of space.  The diameter of each sphere will be about 56 yards, creating 82,500 cubic meter pens.  Construction is expected to begin in 2010. 

Kona Blue farm currently produces open ocean Ahi near the airport, using pens tethered to the sea floor.  Their Ahi show no significant traces of mercury or contaminates, which cannot be said about wild stock.  HOT’s new roaming pen technology is yet another step in the right direction for fish lovers on Hawaii Island and around the world.