Salmon farmer Grieg Seafood is to install semi-closed cages at all three of its farms in Esperanza Inlet, off the west coast of Vancouver Island in British Columbia (BC). The decision follows successful trials of the technology in the Sunshine Coast region, in the south of BC.
The company hopes that the new system will protect the fish in the pens against sea lice and reduce the danger of any interaction with wild salmonids.
The new CO2L Flow system (pronounced “Cool Flow”) is a form of semi-closed containment, which allows for farmers to raise or lower custom designed farm enclosures – ensuring the farmed fish benefit from natural ocean conditions, while also providing protection for wild salmon.
The system uses retractable barriers, which are capable of being lowered to 15 metres, fully encapsulating the sides of the farm. The approach combines lice skirts with cutting-edge aeration technology and was developed in collaboration with several Vancouver Island based technology and services companies – like CPI Equipment and Poseidon Ocean Systems. A leading international oxygen solution company, Oxzo Technologies, was also involved in the creation of some components for the system.
The company said that In all the trials, farmers noted better growth, lower mortality, better feed conversion rates and, most significantly, a dramatic reduction in the need for sea lice treatments.
Rocky Boschman, Managing Director for Grieg Seafood BC Ltd, said: “As ocean-based farmers, one of the most common questions or concerns we hear is regarding sea lice, and the transfer of lice between wild and farmed populations. The CO2L Flow system with its barrier protection has resulted in drastically reduced sea lice numbers on the farmed population, which in turn reduces the need for us to treat. During the trial period at our west coast site, we were able to keep sea lice levels so low that the fish did not require treatment for lice. Overall, we are pleased with the results and there is no denying that this new system represents a transition towards what in-ocean farms can one day become.”
The system will be installed at all three farms in Esperanza Inlet (Lutes Creek farm, Steamer Point farm and the Esperanza farm) in time for the outmigration of juvenile wild salmon in early 2023.