Hawaiian Firm Wants to Grow Seaweed in the Ocean

A company known for its once-controversial unanchored offshore fish pens has plans to get into the specialty seaweed business in a big way.

Kampachi Farms LLC, whose main business is raising the eponymous kampachi, or yellowtail (a popular fish for sushi and sashimi), wants to expand into growing limu. The firm is based in the Big Island city of Kailua-Kona in Hawaii.

Limu are edible underwater plants — seaweed — of various species that have long been an integral part of Hawaiian cuisine but have become especially popular in recent years as a key ingredient of poke — the dish of diced raw fish with other ingredients that qualifies as one of the biggest food fads of the past 50 years across America.

Presently, limu are typically foraged in ocean waters near the shoreline or grown on inland farms. Offshore waters lack the nutrients the seaweed needs to flourish. Kampachi’s plan, as reported in the Honolulu Star-Advertiser, is to grow four species of the plant some 33 feet below the surface, using a wave-powered pump to dredge up nutrient-rich water from depths of about 600 to 2,000 feet.

In a draft environmental assessment, the company described its project as “an innovative and disruptive approach that, to our knowledge, has never before been tested for macroalgae cultivation.”

As much as 12.5 tons of limu could be produced during an initial three-year experimental period, says Kampachi. The seaweed has potential uses not only in poke bowls and other gastronomic treats but also as animal feed and a source of biofuel, which can be used for energy generation. Hawaii is already among the most eco-friendly states.