Submersible Copper-Alloy Mesh Pen Technology in Northern Chile

stillman3By Hal Stillman
Director, Technology Development and Transfer
International Copper Association

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Northern Chile is known for its mountains, deserts, salt lakes, geysers, and hot springs. Although aquaculture is one of the leading industries in Chile, there are no fish farms in its northern coastal waters. Most aquaculture activity takes place in the southern region where Atlantic salmon are raised in abundance. The existence of many protected sites and cold, highly oxygenated water makes southern Chile an ideal location for fish farming.

However, an innovative aquaculture technology, launched off the coast of northern Chile, introduces new geographical possibilities to the fish farming industry. A submersible pen with copper-alloy mesh has been successfully deployed and tested in the exposed open ocean off the coast of northern Chile by EcoSea, a Chilean company using copper alloys to improve productivity and sustainability in the aquaculture industry. The pen, 20 meters in diameter x 10 meters deep, is located at approximately 2 kilometers offshore in Flamenco Bay, 60 kilometers from the Copiapo Airport. It has a robust mooring system and an air hose connection to land. Air pumped to the pen can be used to control the depth of the pen beneath the surface and to provide additional oxygen during periods of low oxygenation in the warmer northern waters.

The pen is stocked with seriola (also known as yellowtail), which are successfully grown in the copper-alloy mesh. Biofouling does not adhere to copper-alloy mesh and therefore greatly diminishes the need for net cleaning. The parasite that affects seriola cannot attach to the copper, and the sturdy mesh protects fish from ocean predators. The pen’s robust submersible system can also withstand rough weather conditions in northern Chile seas. Although submersible cages are not new to the fish farming industry, this is the first structure to use copper-alloy mesh technology.

When EcoSea deployed the submersible copper-alloy cage in 2013, there was uncertainty about whether it would be strong enough to withstand volatile weather patterns in the open sea. Several recent events in Chile have provided true endurance tests for the structure. In September 2015 a magnitude 8.3 earthquake struck central Chile. A tsunami warning was issued. Some coastal cities experienced waves reaching up to 5 meters (about 15 feet). In August of this year, heavy rains and winds caused sea swells with waves reaching up to 10 meters (33 feet) high and in April of 2014 a tsunami warning, following a magnitude 8.2 earthquake, occurred in northern Chile. During these major events, the copper-alloy pen was remotely lowered to 10 meters below the surface. The structure was undamaged and the fish were safe each time.

Rodrigo Sanchez, EcoSea president says, “This shows the strength and resiliency of copper net pens in extreme weather conditions. Our submersible copper pen withstood huge waves and storm surges without any loss of fish or structural damage. This is evidence of the value of pens using copper-alloy mesh to the fish farming industry.”

In 2009, EcoSea began marketing pens with copper-alloy nets for fish production. Today the company is responsible for more than 66 pens with copper-alloy mesh in waters around the world. More than 30,000 tonnes of healthy fish have been harvested from EcoSea’s copper-alloy mesh technology. The company has more than three million hours of experience with fish production using this innovative technology. EcoSea has deployed copper-alloy mesh pens in Canada, Australia, Norway and Chile. Additionally, EcoSea manages its own experimental farm in southern Chile where it develops continuous improvements of its copper-alloy mesh products. The company has harvested a total production of 3,600 tonnes of Atlantic salmon along with yellowtail harvests from the submersible copper-alloy pen in northern Chile.

For further information or questions about EcoSea’s technology, please contact Rodrigo Sanchez or Hal Stillman for information about copper-alloy mesh.