Skip to content
All posts

How Norwegian ASC Sites are Combating Sea Lice

We take a look at how certified farms approach one of the daunting health challenges facing farmed salmon today — sea lice.


Over the last few months, we’ve been working with some of our farmers to improve the complexities around reporting, and specifically the ASC Certification (Aquaculture Stewardship Council). Through that process, we’ve learned what’s required to not only meet the standards, but also some of the challenges that a farm may face in the process of getting certified.

ASC claims to be “globally recognized as the most challenging, transparent independent third-party farm certification to attain.” We wanted to take a look at how certified farms approach one of the daunting health challenges facing farmed salmon today — sea lice.

We're running out of salmon
Salmon have a lousy problem, and the race to solve it is spanning the globe. A surge of parasitic sea lice is…

Given this challenge, we set out to answer the following question:

Are there any differences in treatment patterns between ASC certified sites vs the rest of Norway in combating sea lice?

The Norway aquaculture ecosystem is unique with its availability of data publicized by both ASC and the government. Using this information, we’ve been able to take a look at the various treatment methods available for combating sea lice and compared the usage of those methods within the industry.

To make the comparison we took a look at 3 of the most commonly used techniques to address sea lice:

Sion Barry

Medicinal treatments: In-feed additives (ex. SLICE) or chemical baths to kill lice on salmon

Mechanical treatments: Physical treatments using fresh water, warm water, or brushes conducted on well-boats

Cleaner-fish: Released wrasse or lumpfish that naturally consume lice, both on the salmon and free swimming in the water

Location of all ASC Sites in Norway

We took the information reported by farms over the last 4 years on the three treatment techniques. As of today, there are currently 135 localities actively certified by ASC in Norway, and these sites represent ~25% of all biomass produced in the country. Through the analysis, here’s some of our initial findings:

ASC sites showcase minimal differences as compared to non-certified sites when it comes to the usage patterns of mechanical and medicinal treatments.ASC sites represent significant usage of the country’s cleaner-fish deployments over the last 3 years and particularly during times outside of sea lice outbreaks.

Medicinal Treatments

Over the last few years, the industry has been focused on reducing medicinal treatments, and the data reflects that trend.

Total number of medicinal treatments in Norway (2014–2018)

Since the development of sea lice resistance against SLICE, medicinal treatments as a whole have decreased, and the ASC sites showcased the same trend. The resistance, along with an increased pressure to produce salmon more sustainably, has led to the increasing usage of innovative solutions for combating lice, such as mechanical and cleaner fish.

Percentage of medicinal treatments performed by ASC sites in Norway (2014–2018)

Mechanical Treatments

The reduction in medicinal treatments has led to a large increases in the number of mechanical treatments used throughout the industry. Since 2016, we’ve seen a large increase in the usage of thermolicers and other fresh water treatments for sea lice, and they continue to rise.

Total number of mechanical treatments in Norway (2014–2018)

For ASC sites, the initial data suggests they have been able to keep these mechanical treatments to a minimum, even as other sites continue to report an increases.

Percentage of mechanical treatments performed by ASC sites in Norway (2014–2018)

Cleaner Fish Deployments

Various species of cleaner fish (examples include lumpfish, wrasse) have been utilized as a low impact strategy to reduce lice on a farm. These fish eat lice, and the data shows when farmers are choosing to deploy them on farms. There seem to be large spikes in the results, and we’re starting to see an interesting trend on their usage that we’ll keep a close eye on.

Total number of cleaner fish used in Norway (2016–2018)

Cleaner fish have been promoted as a preventative measure against lice, but there have been challenges in keeping them alive and healthy enough to remain effective for long periods of time. As a result, farms have struggled to utilize them for extended periods of time throughout the year.

Sea lice 'breakthrough' for salmon farmers
The industry hopes to have bred enough sea lice eating wrasse to aid salmon farmers within the next three

Based on the initial data, ASC sites represent a significant portion of cleaner-fish deployments outside of the peak periods. This suggests that these sites are at the forefront of effectively utilizing cleaner-fish as a preventative countermeasure towards lice, but we’ll need to look at some more data to be certain.

Percentage of cleaner fish released in ASC sites in Norway (2016–2018)

Concluding Thoughts

While the results showcased here are only a brief look into what’s happening with sustainable aquaculture in Norway, we’re optimistic at what additional insights are possible as we take a closer look at the data.

In this analysis we took a specific look at comparing treatment differences between two groups of salmons sites in Norway (Standard sites vs ASC Certified sites). Treatments are just a small part of the complexity required for evaluating the sustainability of aquaculture, and we’re looking forward to compare our results with additional factors such as sea lice levels, environment conditions, and feeding decisions.

And that why we’re excited about the work that farms, government, and NGOs are collectively doing to improve the industry’s ability to address health issues by providing the following benefits:

  • Transparency: ASC requires that farms report publicly the results of their audit as well as monthly reports that highlight various activities happening on their farm. (Kvarøy’s ASC Dashboard)
  • Plethora of Data: Farms have taken great strides to collect data over many years so that we can look into the past and effectively measure the results of different methods.
  • Almost Real-time Data: Farms in Norway are asked to report data each week when it comes to treatment and lice, resulting in a vast amount of information that can be quickly shared across the entire industry.
Norwegian Ecosystem for Aquaculture

In our opinion, the availability of this information enables the industry to be better informed on the various activities. It provides a set of information that can be utilized to test and validate results, and that accelerated feedback cycle is critically important to drive the entire industry forward as fast and as sustainable as possible.

If you are curious to see these results in-depth or to hear more about how we are applying big data to address aquaculture health issues at Manolin, feel free to get in touch with me at

Up next, we’re going to look at the new governmental policy (the traffic light system) in Norway and what effect its had on the industry when it comes to treatments patterns in the most critical sea-lice areas.