Harbor's electrical fence prevents sea lice in salmon farms

Sea lice are a naturally occurring parasite on salmon and rainbow trout in saltwater. Infestations can cause wounds, infection, anaemia and even lead to fatality in fish. In Norway alone, there are annual production losses of roughly USD 578 million in direct costs due to sea lice.

Traditional chemical or mechanical methods for combatting sea lice have a negative impact on both fish welfare and the environment. Resistance to delousing drugs or chemicals is growing, while mechanical methods can be stressful to fish.

Harbor AS has developed the Harbor Fence, a non-invasive, chemical-free solution to the sea lice problem. The system uses low-voltage electrical pulses to inactivate sea lice before they attach to the fish. This stops infestation within the cage and further spread to the surrounding environment – without any damage to the fish.

The Harbor Fence consists of three parts: a power supply, a flexible pulse generator and electrodes. The fence itself is made up of two wide-mesh nets from which electrical cables are suspended. The cables send the electrical pulses into the water. The system is also equipped with a monitoring solution that alerts personnel in the event of a power failure.

Full-scale trials have shown that the Harbor Fence reduces the amount of sea lice on salmon by up to 80 per cent. The system is cost-effective and improves fish welfare, production rate and product quality.

The Harbor Fence has no negative impacts on salmon or other organisms in the marine environment, and does not interfere with daily fish farm operations. Used together with cleaner fish, the system can help to reduce the need for chemical or mechanical treatment of sea lice significantly.

In addition, the Harbor Fence reduces the risk of sea lice spreading to wild salmon stocks. Tests also show that the system reduces fouling of fish farm cage nets, which in turn makes the copper impregnation last longer.

The global salmon market achieved a volume of 3.7 million metric tons in 2018 and is projected to reach 4.7 million metric tons by 2024. There are approximately 12 000 salmon pens worldwide. A conservative 15 per cent market share puts the market potential of the Harbor Fence at USD 200 million.

The Harbor Fence is patented in Canada, Chile and Europe.