Sea Grass Production Utilizing Deep Seawater Project

Dr. Ouchi's Project


In recent years there has been increasing reduction in sea grass beds in costal Japan due to poor nutrition in the primary productive forces. Ocean desertification and other factors has led to the loss of richly productive areas.

TSince deep seawater is rich in well-balanced nutrients such as nitrogen and phosphorus, we have developed a sea plant production method to increase sea plant production in the ocean. We are conducting research to improve the sea environment such as preventing ocean desertification.

Content of Experiments

A portion of the water used after OTEC is guided about 400m away to the Maja fishing port where it continuously supplies water to our experimental containers installed near the port’s seabed (about 58tons/day). The nutrient rich cold deep seawater stays in the bottom of the container allowing fertilization with nutrients such as nitrogen and phosphorus. In addition, a control sample without deep seawater allows us to verify the growth of sea plants.

We installed sea plants in December 2014 and have continued to observe growth in both the experimental and control groups.

FY2014 Results and Future Policy

The selected sea plants have been growing steadily in the experimental group. In particular, the sea plants have shown a significant growth rate compared to the control group.

Experimental Group

Immediately After Planting        After 110 Days

Dr. Ouchi's Project

Using this facility, we plan to quantify the deep seawater concentration and growth rate through experiments with different sea plants and to proceed with development of animals such as shellfish through sea plant cultivation.

Ouchi Ocean Consultants Inc.