Managing diseases & parasites

The ASC works to ensure best practice is followed in the monitoring of fish health and the treatment of conditions that can affect them

Fish can be prone to disease, just like humans. Fish diseases and parasites occur naturally, and can affect both wild fish and farmed fish. Sickness can break out even in the best-run farms. Monitoring fish regularly can help to ensure they remain healthy, but – as with humans – there may be times when treatment is required. 

How we help

The ASC standards ensure that medicinal treatments are used safely and responsibly, and the appropriate number of treatments are used. And because science on animal welfare and wellbeing is constantly evolving, we have also embarked on an expert-led Fish Welfare project.

With species such as salmon, diseases and parasites can be passed from one farm to another, or to wild populations in the same area. In such cases, the ASC requires salmon farmers to take part in an Area-Based Management (ABM) scheme for managing diseases and resistance to treatments. This requires them to work together, exchanging information with neighbouring farms and coordinating how they stock fish cages and use medicines.

What are sea lice?

Sea lice are parasites that can affect the health and welfare of farmed fish, particularly salmon. These tiny crustaceans are naturally found on marine fish, and feed on the skin and blood of the fish.

Sea lice can be a problem for farms where salmon gather closely together in one location, making it easier for the lice to spread. There is also a risk that those lice could impact the health of wild salmon populations, if they are migrating nearby.

Sea lice can be a big problem for some fish. ASC standards help to ensure the problem is effectively managed.

How we help

The management of sea lice a critical factor of the ASC standard for responsible farming. This is an issue that is tackled by numerous requirements in the ASC Salmon Standard, and these requirements are currently being reviewed to ensure they are up to date.

ASC certified salmon farms must work with other farms (even if they are not ASC certified) in their area to create an Area Based Management plan to minimise the collective impact of the farms. No ASC farm can use chemical treatments that have been banned in any salmon producing country, and all chemical treatments must be signed off by a vet before use.  The ASC Salmon Standard also sets very strict limits on chemical treatments, requiring that farms use non-chemical treatments instead wherever possible, keep the number of chemical treatments below strict limits and ensure  any chemicals do not affect local biodiversity.

Is the industry taking this seriously?

It is also an issue that the wider industry is taking very seriously. All farmers have to deal with parasites and disease, but the aquaculture industry is an innovative industry and many new solutions are being trialled to deal with sea lice that don’t involve potentially harmful chemicals. just some examples currently being used or researched include thermal treatments; ‘snorkels’ that form a barrier against sea lice while allowing salmon to reach the surface of the water; and anti-sea lice feed. This is fast progress for an industry that is only a few decades old, but there is always more to be done, and ASC will continue to encourage farms to further reduce their use of chemicals.

Can more be done?

At ASC we share people’s concerns about the impact of sea lice on farmed salmon, which is why are reviewing our requirements on this area. The ASC Salmon Standard already includes requirements limiting the number of sea lice that present during sensitive periods for any nearby wild salmon populations, but this review will look at the latest evidence to see if these requirements can be further strengthened.

We have also commissioned research in British Columbia to better inform the sea lice debate. This research will dive into data from BC farms to provide in-depth insights into sea lice levels throughout the year, how and when these numbers go up, as well as what effect different treatments have. The data will come from multiple sources, including ASC certified farms which must publish such data as a requirement of certification. This will be used to inform the review of our standard, but we envisage it also having wider implications to others in the industry.

Support responsible farmers: Look for the logo!

If, like us, you want to only shop and eat seafood products that have been produced with care by farms using medicinal treatments responsibly, simply look out for the ASC logo when you shop and eat out. And if it’s not there – ask why not!