Day Ten – The riches of deep seawater


On day 10, we experienced the Hawaii Ocean Science and Technology Park which is administered by National Energy Laboratory Hawaii Authority (NELHA). The park is a collection of 42 groups, which range from research and development teams, business clients, and government agencies that utilize the collection of deep sea water. There are three different pipelines that acquire seawater from the surface and 3000 ft deep. The entire complex spans 870 acres along the Kona coast.

Introducing us to facility was Candee Ellsworth from Friends of NELHA. Friends of NELHA is a nonprofit organization that helps educate the public on the benefits of sustainable technologies at the Hawaii Ocean Science and Technology Park. We met in the Gateway Visitor Center to review the projects taking place at NELHA. The Gateway visitor center is a Zero Energy Building and received a LEED Platinum rating. The building is designed as a thermal chimney to eliminate the need for any external energy to power and cool the building. The copper roof radiates heat which then is exhausted through vents at the side of the building. Fresh air from outside is pulled into the building to replace the heated air. The incoming air is cooled by being drawn across 45°F seawater. Condensation forms on the pipes and is used for flushing toilets and irrigation in the front yard. The orientation of the building allows the photovoltaic array on the roof to collect enough energy to provide for all the building’s energy needs.

Friends of nelha
Gateway visitor center. Photo: Friends of NELHA

Our first stop on the tour was Kampachi Farms where we met with Cory Hungate and Daren Garriques. Cory and Daren described how their mariculture company focuses on expanding technology related to fish selection and open ocean nets. Their primary fish is the namesake of the company, Kampachi. Kampachi is similar to the wild fish known as Almaco Jack or Kahala but differs in a few important ways. The farm raised Kampachi are free of ciguatoxin and have a feed conversion rate of 1.4, which is better than most fish and land-based livestock. They are also raising Pacific Giant Groupers on a smaller scale, which we were able to view in two tanks. These fish are massive with their “small” broodstock weighing 250 lbs each. We were told not to place our hands over or near the tanks as the fish might confuse us for food. Their newest study will be looking at the ability to raise Mahi Mahi. The initial hurdle will be to deal with the aggressive nature of young, male Mahi Mahi.

Pacific Giant Grouper. Photo: Scott Delgado

The second site on the tour was the Ocean Thermal Energy Conversion (OTEC). OTEC uses the temperature difference between seawater at the surface and deep cold water at 3000ft to create electricity. The facility currently creates 100 kW of energy and is the first connected to an electrical grid. More information about OTEC can be found below.


OTEC. Photo: Scott Delgado
OTEC. Photo: Scott Delgado

The final location was Big Island Abalone where Al Salomon explained the process of raising Japanese Northern abalone. Before entering the facility, we were required to rinse our shoes in an iodine solution and wash our hands with sanitizer as they were concerned with biocontamination. The facility had hundreds of tanks filled with abalone of differing sizes. Each tank had approximately 4,500 abalone with the entire facility maintaining two million individuals. These abalone are not native to Hawaii so all production takes place on land. If any spat found its way past their filtration system, they would not survive the warm Hawaiian waters. At the end of the tour, we were able to handle live abalone in a touch tank and to taste grilled abalone. The opinions of the class were mixed, as some students followed their abalone with quick gulps of water, while others went back for seconds. Regardless of the taste, it was quite an experience to try seafood that can cost up to $300/lb.