Site Details: Grey Horse Channel Outer

Hoebeg Cheesebay
Loch Maddy
North Uist
HS6 5AT
Operator: Mowi Scotland Ltd
Water type: Seawater

Average female lice per fish

Source

Salmon Scotland mortality

Source

Cumulative mortality over full production cycle

Production cycle end date: Aug 2020
Total losses: 15.8 %

Production cycle end date: Dec 2020
Total losses: 8.9 %

Production cycle end date: Jun 2022
Total losses: 55.9 %

Source

Fish Health Inspectorate mortality

Date:
17/01/22-23/01/22
Mortality:
8,864
Mortality Rate:
1.27%
Reason given: Treatment losses / Complex gill diseases and AGD
Treatment losses / Complex gill diseases and AGD
increased mortalities the result of peroxide treatment for AGD. FHI to monitor.
Date:
07/02/22-13/02/22
Mortality:
7,886
Mortality Rate:
1.16%
Reason given: Complex gill diseases and AGD
Complex gill diseases and AGD
Mortalities have reduced since H202 treatment. FHI to monitor.
Date:
28/02/22-06/03/22
Mortality:
7,184
Mortality Rate:
1.08%
Reason given: Gill Disease/ Predator/ Yersiniosis
Gill Disease/ Predator/ Yersiniosis
Contacted site manager, antiobiotics have been administered which has reduced the mortalities below the reporting threshold. FHI to monitor.
Date:
07/03/22-13/03/22
Mortality:
7,551
Mortality Rate:
1.22%
Reason given: Gill Disease / Yersiniosis
Gill Disease / Yersiniosis
Antibiotic treatment administered between 19/02 to 03/03 which is addressing the bacterial issue. Complex gill disease still prevalent although mortality is reducing. No further treatment plans in place at the moment.
FHI to monitor.
Date:
14/03/22-20/03/22
Mortality:
8,705
Mortality Rate:
1.43%
Reason given: Complex gill issues, Seal damage
Complex gill issues, Seal damage
Data collected during inspection. Site visited 25/05/2022. Report for 2022-0164 to remind business of agreement in relation to mortality reporting as detailed in A Code of Good Practice for Scottish Finfish Aquaculture.
Date:
21/03/22-27/03/22
Mortality:
6,268
Mortality Rate:
1.04%
Reason given: Gill Disease / Treatment Loss
Gill Disease / Treatment Loss
Salmosan treatment administered in week 11 to reduce sea lice load on site. Complex gill disease continues. Extended FW treatment planned for week 14. FHI to monitor.
Date:
28/03/22-03/04/22
Mortality:
6,174
Mortality Rate:
1.04%
Reason given: Complex gill issues
Complex gill issues
Data collected during inspection. Site visited 25/05/2022. Report for 2022-0164 to remind business of agreement in relation to mortality reporting as detailed in A Code of Good Practice for Scottish Finfish Aquaculture.
Date:
04/04/22-10/04/22
Mortality:
7,065
Mortality Rate:
1.39%
Reason given: Gill Infection & Predation
Gill Infection & Predation
A number of seal attacks occurred wk 14 which accounts for most of the mortalities with a small part of the percentage down to gill issues. Mortality numbers have reduced wk 15.
FHI to increase monitoring
Date:
25/04/22-01/05/22
Mortality:
6,213
Mortality Rate:
1.26%
Reason given: Complex gill issues
Complex gill issues
Data collected during inspection. Site visited 25/05/2022. Report for 2022-0164 to remind business of agreement in relation to mortality reporting as detailed in A Code of Good Practice for Scottish Finfish Aquaculture.
Date:
02/05/22-08/05/22
Mortality:
5,763
Mortality Rate:
1.19%
Reason given: Gill disease / Treatment Loss (Freshwater)
Gill disease / Treatment Loss (Freshwater)
Extended FW treatment conducted in week 18, which exacerbated mortalities. Complex gill disease still prevalent on site. A reduction in mortality has been observed. FHI to consider visit as inspections are planned in the area w/b 23/05/2022. FHI to monitor. - Report updated 9/8/22 by SAE based on records collected for 2022-0230 from 1.01% to 1.19% and 4914 to 5763.
Date:
16/05/22-22/05/22
Mortality:
Mortality Rate:
1.08%
Reason given: Seal Predation
Seal Predation
Buisiness corrospondat contacted, awaiting response. Mortality levels are reducing and are expected to be below reporting threshold. FHI Visited WB 23/05/2022
Date:
06/06/22-12/06/22
Mortality:
7,858
Mortality Rate:
1.76%
Reason given: Complex gill issues
Complex gill issues
not reported, discovered during record check for case 2022-0230, site now fallow.
Date:
13/06/22-19/06/22
Mortality:
11,693
Mortality Rate:
2.67%
Reason given: Gill infections / Seal predation
Gill infections / Seal predation
AGD confirmed on site, freshwater treatments currently in progress. Seals seem to be targeting fish affected by gill issues. FHI to monitor.
Date:
08/04/24-14/04/24
Mortality:
4,131
Mortality Rate:
1.32%
Reason given: Gill infections
Gill infections
Business contacted: Fish were transferred from Groatay at the end of February and through March. Fish were treated with FW when they were transferred.
Business contacted for information. FHI to monitor.

Source

Inspection reports

Case Number: 2021-0378


Download Issue with AGD in recent weeks.
Lumpfish will be delivered in November to be stocked at 6-10%.
Stock from Inchmore Hatchery.
Issues with Caligus, treated twice with Alphamax at the end of August. No consent for Slice.
Week 37 2021: 4-8,000 dead fish per pen. Peroxide treatment delayed, treatment started on the 18th of September, treated 3 pens before machine broke down, treated the rest of the pens after 3 days. Mortality reduced once treatments were completed.
Peroxide treatments ongoing - Pen 51 (worst affected) treated on 3/10, pens 48-50 on 4/10, pens 41-42 on 5/10 and pens 43-
44 on 6/10 (treatments ongoing during inspection). The most recently treated pens had a number (between 10 to 40) of floating mortalities on the surface, while those treated earlier in the week had much lower numbers of moribunds and no dead fish on the surface.
Physical inspection carried out by and on 06/10/21. VMD and diagnostic sampling done by , observed by
The fish sampled had poor gills but showed no other clinical signs of disease. [Original PDF]

Case Number: 2022-0164


Download Remote inspection carried out 18/05/2022. Site to be visited following reports of increased mortalities.
The main cause of mortality has been attributed to seal predation. Complex gill disease issues have also been identified and an extended freshwater treatment was conducted in week 18, which exacerbated mortalities but alleviated the gill problems.
The site is in the process of changing nets from nylon to SealPro to try and reduce seal damage. Two nets are left to change and these are the pens still experiencing higher mortalities, the remaining cages are currently experiencing background mortality numbers.
Mortality events: weeks 40 to 44 2021 plus weeks 3, 6, 9, 10, 12, 14, 18, 20 2022 reported to FHI.
Week 11, 13, 17 not reported to FHI, see mortality events for additional info.
The weather conditions during the site inspection made it harder to observe the fish as they were deep in the water column.
Fish with seal damage could be observed swimming amongst the main population. The site staff was observed removing mortalities from one of the nylon net pens and the majority of the dead fish also presented seal bites. A small number of anorexic, lethargic fish was also seen in most cages, however these fish would swim away when approached. Three surface dead fish seen on site. Very little sea lice was observed on the fish.
The stock has been problematic since input - not feeding well, lethargic, high percentage of poor performers. Some of the fish were transferred to Grey Horse Channel in early April to thin out the cages. Three lethargic fish from this stock were removed from Grey Horse Channel and upon internal examination, it was found that the fish were sexually maturing. No gross pathology observed.
Harvesting will begin at the end of May and the site expected to be fallow by August 2022. [Original PDF]

Source