Site Details: Ness of Copister

Yell Shorebase
Mid Yell
ZE2 9BN
Operator: Cooke Aquaculture Scotland Ltd
Water type: Seawater

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Average female lice per fish

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Salmon Scotland mortality

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Cumulative mortality over full production cycle

Ness of Copister Production cycle end date: Jan 2019
Total losses: 13.8 %

Ness of Copister Production cycle end date: Jan 2020
Total losses: 12.6 %

Ness of Copister Production cycle end date: Jan 2021
Total losses: 7.1 %

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Fish Health Inspectorate mortality

Date:
02/10/23-08/10/23
Mortality:
73,854
Mortality Rate:
5.36%
Reason given: Handling/Gills
Handling/Gills
Site contacted for further information. One off mortality event has occurred following a peroxide treatment. Mortality on site has now significatly reduced and is back below the reporting threshold.
FHI to monitor.
Date:
23/09/24-29/09/24
Mortality:
41,334
Mortality Rate:
3.68%
Reason given: Handling/gills
Handling/gills
Mortality levels reduced onsite for week 40
First report this cycle. FHI to monitor.
Date:
29/09/25-05/10/25
Mortality:
17,129
Mortality Rate:
1.35%
Reason given: Gill Health/Environmental
Gill Health/Environmental
Business contacted for additional information: site currently treating with FW, treatment will conclude this week.
First report this cycle. Business contacted for additional information. FHI to monitor.
Date:
06/10/25-12/10/25
Mortality:
20,749
Mortality Rate:
1.66%
Reason given: Gill Health/Environmental
Gill Health/Environmental
Business contacted for additional information: FW treatments on-going as delayed by adverse weather conditions. 2 pens remain to be treated this week. Increased mortality for wk 42. Treatment has been effective on pens that have been completed. Histology report from the business for the site shows complex multifactorial gill disease.
Business contacted for additional information. FHI to monitor.
Date:
13/10/25-19/10/25
Mortality:
35,065
Mortality Rate:
2.85%
Reason given: Gill Health/Environmental
Gill Health/Environmental
Business contacted for additional information: FW treatment completed, mortality decreased for wk 43 below reporting threshold.
Routine FHI vist is scheduled for next month. Business contacted for additional information. FHI to monitor.
Date:
10/11/25-16/11/25
Mortality:
44,494
Mortality Rate:
3.8%
Reason given: Gill Health/Environmental
Gill Health/Environmental
Treatment started
FHI visit scheduled

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Inspection reports

Case Number: 2022-0419


Download Ness of Copister is not a harvest site. Smolts are ongrown here to approx. 2kg and then transferred to various other sites around Yell and Unst where they will be grown to harvest size (seen as a nursery site). Input of smolts at 85 to 120g.
Own small shorebase where mortalities are collected at and taken away by bulk transporter to either TWMN (Shetland) or SEM (depending on quanity and available space at facilities).
Stock of fish on site either from Migdale (Jubilee) in Loch Shin (pens 1,8,9,16) and Furnace (pens 2,4,6,7,10,11,12).
Remaining pens will be used for grading.
No cleanerfish on site/company wide.
From site inspection, slight AGD observed. Lice are increasing but not causing concern.
VMD samples taken on 13/09/2022, All fish sampled for VMD were observed to be in good condition. [Original PDF]

Case Number: 2022-0419


Download Ness of Copister is not a harvest site. Smolts are ongrown here to approx. 2kg and then transferred to various other sites around Yell and Unst where they will be grown to harvest size (seen as a nursery site). Input of smolts at 85 to 120g.
Own small shorebase where mortalities are collected at and taken away by bulk transporter to either TWMN (Shetland) or SEM (depending on quanity and available space at facilities).
Stock of fish on site either from Migdale (Jubilee) in Loch Shin (pens 1,8,9,16) and Furnace (pens 2,4,6,7,10,11,12).
Remaining pens will be used for grading.
No cleanerfish on site/company wide.
From site inspection, slight AGD observed. Lice are increasing but not causing concern.
VMD samples taken on 13/09/2022, All fish sampled for VMD were observed to be in good condition. [Original PDF]

Case Number: 2025-0447


Download Ness of Copister is primarily used as an S1 nursery site and is the only site operating within the Disease Management area
(DMA).
Mortality events had been reported to the FHI weeks 40 through to 42 and week 46. Main issue was complex gill issues, primarily AGD across the whole site. Week 47 mortality levels were above reporting level (2.74%, 30,823) but are yet to be reported at time of inspection. This is a reduction from the previous week.
Freshwater bath treatments began on site on 24/11 and aim to be completed by 07/12, weather permitting. A portion of the fish have been transferred to other sites for further growing and were given a freshwater treatment while in transit. Early indications show this to have improved their health.
On visual inspection of the site the vast majority of fish could be seen shoaling well deep down and responding well to feed. A small number of fish (5-10) per pen appeared slightly lethargic but had a good startle response so were not removed for sampling. There was a higher number of fish hanging out near the surface in 3 of the pens but this was due to them not being fed in preparation of treatment in the next couple of days.
2 fish were removed for VMD sampling and appeared in good condition with no external damage or haemorrhaging. Internal examination also showed the fish to be in good health.
The Biosecurity Measures Plan, mortality records, treatment records, sea lice records and Farm management Statement was inspected remotely on 19/11/2025. Movement records, waste transfer notes and surveillance results were inspected on the day of the site inspection, 25/11/2025. [Original PDF]

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