Scottish Sea Lice Statistics: updated weekly

Has Scottish Government done anything this week to limit the impact of sea lice on wild fish?

In the event that a farm is registering very high sea lice levels the Scottish government can take certain actions, such as issuing an advisory letter to the farm in question.

Week 46:

The Scottish Government have not taken any action this week.

Proportion of farms in breach of CoGP:

Farms in breach of Scottish gov limits:


Farms above 2 sea lice per fish


Farms above 6 sea lice per fish

Company with the highest average lice levels

Farms in operation
Company Name Mowi Scotland Ltd

Farm with the most weeks in breach:
Shuna Castle

Company Name Kames Fishing Farming Ltd
Location Loch Melfort, Argyll

Farm with highest sea lice (average per fish)

Farm name North Voe
Farm company Scottish Sea Farms Ltd
Location Shetland Islands
Lice Number 2.38 lice per fish
District Salmon Fisheries Board* No DSFB

*District Salmon Fisheries Board’s are statutory bodies tasked with protecting and enhancing stocks of salmon and sea trout within their districts.

What does this figure mean?

Farm with highest sea lice levels (average per fish):

This figure shows the highest self-reported values of average sea lice per fish from the last reported week of data from farmers. There is no consistent methodology for how to record this value, and it is likely to be an underestimate based on testing of other self-reporting sea lice schemes.


The average number of adult female sea lice (AFSL) reported on every farm in Scotland since legislation required it to be publicly reported.

The highest average value for each week is highlighted in red, while average values from other farms are in orange.

Yellow lines show Scottish Government (SG) imposed limits of 2 AFSL, which initiates higher monitoring, and 6 AFSL which can lead to further action from SG.

Blue lines show the Salmon Scotland Code of Good Practice limits agreed upon by industry, which set a limit of 0.5 AFSL during the sensitive period for out-migrating salmon from 1st February – 30th June (grey shaded area) and 1.0 AFSL from 1 st July – 31st January.

Proportion of farms in breach of CoGP:

The industry sets out a standard for acceptable sea lice levels in the Code of Good Practice (CoGP). These change throughout the year and are not the same as the Scottish governments reporting thresholds. The above values are based on the reported values of average sea lice per fish exceeding the acceptable threshold set out in the CoGP.

Farms in breach of Scottish Government lice limits:

The Scottish government sets a much higher threshold for action than the industry standard. The Scottish government requires a higher level of surveillance by the Fish Health Inspectorate at 2.0 adult female lice (AF) per fish, and potential for action (advisory letters or enforcement undertakings) if a level above 6.0 adult female lice (AF) per fish is maintained.

Company with the highest average lice levels:

The mean value of average lice across all the farms of each business based on the above reported average sea lice values on each farm for the last reported week.

Most weeks in breach:

The value for cumulative weeks in breach is based on our assessment of breach or CoGP from the self-reported average sea lice data. The value of the threshold for breach changes over the year reflecting wild salmon migrations. This figure takes account of the changes in the threshold.

View sea lice hotspots map

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