Here's how one company is spending $300 mn to farm salmon in the deep seas

The semi-submersible Ocean Farm 1 off the coast of Norway can hold 1.5 million fish

Three miles off Norway’s rugged coast, 1.5 million salmon swim in a 220-foot-high, football-field-long mass of floating mesh-wire frames and nets. This is Ocean Farm 1, the world’s first deep-sea aquaculture project, designed by leading salmon farmer SalMar ASA. The company paid China Shipbuilding Industry Corp $300 million upfront for six facilities that offer more space than conventional shoreline farms (large nets in sheltered waters) while diffusing fish waste, allowing them to be packed in tighter.   

How it works

Oxygen sensors and high-definition cameras monitor the salmon for, among other things, growth and signs of illness. Midway through Ocean Farm 1’s yearlong trial run, SalMar says it’s seen strong growth and low mortality rates.

Sixteen movable, submerged valves disperse food at set times and allow fish to live at depths of up to 180 feet, rather than clustering them near the surface, as in other farms.

Next steps

SalMar plans to harvest the farm’s first generation of salmon in the second half of the year and says that if the development phase is successful, it’ll be possible to establish fish farming anywhere in the open sea. The company says OF1 can withstand devastating waves, on the order of 50 feet.

One drawback: Packing so many fish so closely together heightens the risk of widespread disease if even a few get sick. It also forces the salmon to stay in much deeper water with less oxygen than they’re used to, which limits their growth, according to Tim Dempster, a marine ecologist and professor of biosciences at the University of Melbourne.