Controlling the sea lice levels on our sites is one of the most important measures the industry can take to protect the wild salmon, particularly when the wild salmon is still at the smolt stage. Too much sea lice can also harm the farmed salmon’s health and welfare. Further, sea lice treatments are costly, stressful for the fish, resource intensive and can reduce quality. For these reasons, we aim to keep sea lice levels low at all times.
Sea lice levels shall stay below the legal limit of 0.5 mature female lice on our fish farms in Norway. We aim to achieve the same levels throughout the Company, even though the legal limits are higher in Canada and Shetland. On our green licenses, the sea lice limit is 0.25.
Between April and June, when the wild salmon smolt swim out of the rivers and pass the salmon farms, the sea lice limit decreases to 0.1 mature female lice per site in Norway.
Our main approach to sea lice control is prevention. We aim to keep sea lice levels low with various preventative measures applied at all times.
When the sea lice limit rises above 0.3 mature female lice at a site, it is Company policy to apply additional measures.
If we need to use sea lice treatments, we favour non-chemical delousing methods, to avoid affecting the environment and other species in the ocean. However, when selecting treatment, fish welfare and potential resistance to sea lice treatments are also considered.
If, as a last resort, we need to use medical treatments, we revolve the use of various medicines to avoid resistance to the treatments.
We collaborate with neighbouring fish farmers to control sea lice in our
HOW WE WORK TO IMPROVE
Our approach to sea lice control
We use roe that has proven more resistant against sea lice when available.
EFFORTS TO REDUCE ENVIRONMENTAL IMPACT OF SEA LICE TREATMENTS
- While we try to avoid using medical sea lice treatments at all, there are some instances when it is necessary. In such cases we try to do it with as much care for the environment as possible.
- There is some evidence that shrimp and crustaceans are susceptible to a type of medicine, flubenzurons, or so-called chitin inhibitors, used in-feed to fight sea lice. In order to secure responsibly low emission levels locally, we have imposed a restrictive use of these agents, especially chitin inhibitors. We adhere to the recommended advice for using these agents.
- We also have procedures to prevent the release of water containing treatment medicines against sea lice in areas close to shrimp fields or spawning grounds, in compliance with regulations from the Norwegian Environment Agency.
- We follow closely ongoing research projects that look into potential impact from sea lice treatments on other marine species.
OTHER SEA LICE EFFORTS
- All regions have comprehensive plans and strategies for sea lice control.
- Systematic monitoring of sea lice levels.
- In Norway and the UK, we count sea lice every week at water temperatures above four degrees, and every other week at water temperatures below four degrees.
- In BC, we follow local regulations where counts depend on sea lice levels. In BC, farmed salmon usually catches sea lice from the wild salmon when they pass farms on their way out to the ocean. Here, unlike Norway, the wild salmon population greatly outnumbers the farmed salmon population.
- We collaborate with other salmon farmers through Area Based Management, to control sea lice in all of our areas.
- We have meeting between the various regions to learn best practice sea lice management from each other.
- Long and synchronized fallowing periods is the most important prevention method to reduce the sea lice pressure on the next generation.
- We take part in the Aqua Cloud artificial intelligence project, which aims to be able to predict sea lice levels in advance and use preventative methods in cases of outbreaks.
- Our post-smolt strategy will also reduce the time that each fish
spends in sea, another measure to reduce sea lice exposure per fish.