In a small, quiet village in Western Japan, steam billows out of the surrounding mountains, natural hot mineral water flows into the village onsens (hot springs) soothing aching bones of the many appreciating guests. From the baths, one can see the glistening sea, work boats puttering from pen to pen checking their fish as their ancestors have been doing for generations. Things are changing here though, and this small farming village is at the forefront of cutting edge aquaculture technology. In the group of 30 small pens, two unique ones exist, instead of standard synthetic mesh or conventional steel wire mesh, they are using copper alloy mesh.

EcoSea Farming’s copper alloy mesh

The difference is immediately apparent when peering into the pens from above; the gold color mesh can be seen until it disappears in the deepest water. The neighboring pens, using more traditional mesh, are blackened by fouling which inhibits the flow of water isolating the fish from the world outside. These two pens were set up as a demonstration to show the benefits of using copper alloy mesh for aquaculture production.

Japan is an aging country. Most young people prefer the glamor and bustle of the city and have little interest in performing manual labor nor living in small quiet villages. This trend is one of the many reasons why it is imperative that farmers learn how to feed the world with older and fewer staff.  EcoSea’s copper alloy aquaculture pens reduce the hours needed to maintain the pens, divers are required less frequently, and cleaning the mesh is something more or less of the past.  Farmers can focus their efforts on raising crops instead of washing or changing nets as they have had to do for years. This demonstration only used a subset of EcoSea Farming’s technology; implementing additional EcoSea technology would further reduce necessary staffing while increasing crop yields, produce a better and consistent quality product, and raise farm profitability. Fish raised in this environment will meet and exceed international certification requirements and increase the potential to supply products overseas, changing Japan from a net importer to a major exporter of high-quality fish to the rest of the world.

EcoSea plans to change the Japanese aquaculture industry for the better. Our vision includes farmers with large offshore systems producing top quality fish in an environmentally sustainable way. The two small copper alloy mesh pens that were set up in that remote village in Western Japan were just the first step towards EcoSea’s dream of seeing kitchens around the world stocked with high-quality fish produced in Japan.

Demonstration Results

The results in this chart compare a copper alloy pen (A1) against a metal alloy pen (E6) control. A total of 4 pens were used in the demonstration, two test pens and two control pens, all sized 10m X 10m X 8m. The results of all pens were nearly identical to the two selected for this chart. The testing period was from November 2016 through May 2017.  In November 2016,  Seriola quinqueradiata (BURI), weighing about 2.5kgs each, was placed into the pens; the fish were harvested in May 2017 and weighed approximately 5.5kgs each. The fish were fed a diet of extruded pellets (EP) designed specifically for this species. The specific growth rate (SGR) demonstrated an improvement of about 40% over the control pens and approximately a 45% reduction in accumulated mortalities. A sizeable improvement in the feed conversion ratio (FCR) rates were also observed.

It is important to note that for this demonstration that only the nets were changed; two pens with metal nets were replaced with copper alloy mesh nets. No special technology from EcoSea framing was applied, which confirms that incremental improvements can be realized from switching to copper alloy mesh. Utilizing EcoSea systems and technology combined would yield significantly improved results.