Average female lice per fish

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Salmon Scotland mortality

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Cumulative mortality over full production cycle

Coledeep Production cycle end date: Jan 2020
Total losses: 40.1 %

Coledeep Production cycle end date: Feb 2022
Total losses: 12.8 %

Coledeep Production cycle end date: Jun 2024
Total losses: 14.7 %

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Inspection reports

Case Number: 2021-0269

Download 1 dead observed near middle of cage 9, not fresh dead. No issues reported on site, sea lice numbers very low. There had been an increase of caligus at neighbouring sites, but numbers still low at Cole Deep.
1 fish sampled for VMD appeared healthy, with very few lice observed, no adult female Leps.
Very calm weather and good visibility. Fish were deeper in the water column, but cages being fed showed a good feed response. All feeding at GSS sites is now conducted remotely from a central 'control' room at the main office in Lerwick.
All harvests for site are planned to be dead haul. [Original PDF]

Case Number: 2023-0223

Download Fish visually inspected on site appeared healthy with only 2 lethargic fish observed across the whole site. Fish removed for vmd sampling showed no gross pathology when examined.
Mortality records showed mortality levels were at 1.63% & 1.51% for pens 9 & 7 over week 44 2023. This was attributed to failed smolts/ post transfer but overall site mortality level remained below reporting level. Whole site mortality reach 1.6% week
47 2023 (21/11 - 27/11), again attributed to transfer of stock and physical damage. This was reported to the FHI. [Original PDF]

Case Number: 2025-0448

Download Site inspected after reports of increased mortalities which began week 43 (20/10/25), with mortality levels reported at 2.1%
(11,760). Mortality levels increased to 12% (64,080) the following week but have continued to drop in the following weeks but still remained above reporting level to present.
Health checks have identified AGD & PGD as the cause as a result of record high sea temperatures for the time of year. The water temperature was still >11oC as of 13/11/2025 but has dropped below 10oC in the last couple of weeks which has helped the situation. Recent health check have also noted a secondary bacterial infection on a few individual fish but a good appetite is still being observed.
Freshwater/FLS treatments have been conducted recently, with the most recent being carried out on 05-08/11/25. A further freshwater/FLS treatment is scheduled week beginning 08/12/25.
The site made the decision to start harvesting the fish early and are down to 3 remaining pens, 1 of which will be partially harvested 29/11/2025. The decision to completely harvest out the site will be made later based on the health of the fish. If the decision to completely harvest is made, the site will be fallow before Christmas.
Removal of moribund fish is taken place with fewer than 5 fish per pen being removed on a daily basis. Upon inspection of the remaining stock only 2-3 fish per pen were observed to be slightly lethargic but were unable to be caught for sampling. A few fish were also observed to have white caps from sea lice damage but appeared to be healing well and were seen to be shoaling well deep in the water column. [Original PDF]

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