Site Details: Grey Horse Channel
Loch Maddy
North Uist
HS6 5AT
Water type: Seawater
Cumulative mortality over full production cycle
Production cycle end date: Feb 2019
Total losses: 28.2 %
Production cycle end date: May 2020
Total losses: 17.1 %
Production cycle end date: Dec 2020
Total losses: 8.9 %
Production cycle end date: Jul 2022
Total losses: 44.2 %
Fish Health Inspectorate mortality
07/02/22-13/02/22
7,688
1.00%
07/03/22-13/03/22
6,426
1.04%
28/03/22-03/04/22
5,728
1.02%
04/04/22-10/04/22
5,514
1.02%
11/04/22-17/04/22
10,209
1.91%
18/04/22-24/04/22
6,813
1.32%
25/04/22-01/05/22
6,213
1.26%
30/05/22-05/06/22
7,457
1.84%
06/06/22-12/06/22
4,773
1.22%
13/06/22-19/06/22
5,227
1.36%
20/06/22-26/06/22
5,618
1.48%
27/06/22-03/07/22
7,432
1.99%
04/07/22-10/07/22
8,966
2.6%
11/07/22-17/07/22
4,571
2.03%
05/09/22-11/09/22
1,396
1.55%
19/09/22-25/09/22
2,677
1.16%
30/01/23-05/02/23
862
1.26%
28/08/23-03/09/23
14,017
1.23%
04/09/23-10/09/23
24,989
2.21%
11/09/23-17/09/23
18,820
1.70%
25/09/23-01/10/23
12,310
1.14%
02/10/23-08/10/23
47,228
4.43%
09/10/23-15/10/23
63,864
6.27%
16/10/23-22/10/23
45,333
4.75%
23/10/23-29/10/23
26,590
2.93%
30/10/23-05/11/23
32,807
3.72%
06/11/23-12/11/23
29,020
3.91%
13/11/23-19/11/23
14,515
2.04%
20/11/23-26/11/23
12,254
1.75%
27/11/23-03/12/23
9,347
1.36%
11/12/23-17/12/23
9,031
1.35%
18/12/23-24/12/23
6,909
1.04%
19/08/24-25/08/24
4,715
1.15%
Inspection reports
Case Number: 2020-0188
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Mortality information - reported. week 14 - 1.01% - 4566 fish @ 3.3kg- Clinical CMS week 17 - 1.47% - 4757 fish @ 3.4kg - CMS and PD week 18 - 2.04% 5514 fish @ 3.4kg - Losing fish due to CMS and PD, 1 pen had acute losses from treatments. week 19 - 1.89% 4996 fish @ 3.4kg - CMS and PD - Fish being harvested out
Site to be harvested out. Starting 16/05/2020 site expected to be empty by end of may. All pens were first thinned to see if that would help mortality, still seeing consistent CMS and PD mortality so decision to harvest out site was made.
FVG did a full diagnostic which confirmed the presence of CMS and PD. [Original PDF]
Case Number: 2021-0377
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5 pens to be transferred to West Loch Tarbert in October due to temperature variations being too high in West Loch Tarbert in the summer while the temperature profile in Cheesebay is colder and more stable.
Lumpfish will be delivered in November to be stocked at 6-10% - from Wales
Salmosan treatment start of September 2021.
Peroxide treatment week 38 2021.
Stock from two different hatcheries. One stock performing worse than the other - not feeding well, lethargic, growing slowly and positive for AGD. Pen 12-13 worst affected, lost 3.5% in week 38.
2 small holes found in pen 12 at 0.5m depth initially thought to be caused by predator damage. Three seals observed on site. incident reported to FHI (Marine Scotland incident reference: MSe061021SAL1) and said to be caused by lumpfish feeder rubbing against already patched net. The holes were repaired upon discovery and the following corrective action will be taken: feeders will be pivoted away from the net to leave a greater distance between them to prevent future holes. In some cases feeders will be removed of cages completely where they are not required. No fish have been lost.
Site currently replacing all top nets.
Physical inspection carried out by and on 06/10/21. VMD sampling done by observed by .
The fish sampled for the VMD showed no clinical signs of disease. [Original PDF]
Case Number: 2022-0163
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Remote inspection carried out 18/05/2022. Site to be visited following reports of increased mortalities.
A number of seal attacks occurred starting from week 14 2022 which account for most of the mortalities. AGD has also been identified as the additional cause of mortality in the stock transferred from Grey Horse Channel Outer (01/04/2022) This stock has been performing poorly since input, not feeding well and growing slowly. Pens 4, 6, 7, 11, 12, 13, 14.
Harvesting has begun in April and the site is expected to be fallow by August 2022.
Mortality events: weeks 41, 44, 45, 51 & 52 2021 plus weeks 6, 14 - 17 2022 reported to FHI.
Mortalities for weeks 10 & 13 2022 not reported to FHI, see mortality events for additional info.
During the site inspection no moribunds or dead fish could be seen in the cages containing Glenfinnan stock. Some seal damage could be observed in the main population. The pens containing the fish moved from Grey Horse Channel Outer also had a small number of anorexic and lethargic fish near the water surface. Three fish could be sampled and brought to shore for further checks and upon internal examination it was found that they were sexually maturing. No gross pathology was observed. The fish sampled for the VMD looked healthy both internally and externally with minimal sea lice load. [Original PDF]
Case Number: 2023-0458
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Peaks in salmon mortality 2022, wk 22 7457 (1.84%), wk 23 4,773 (1.22%), wk 24 5,449 (1.41%), wk 25 5,618 (1.48%), wk 26
7,432 (1.99%), wk 27 8,966 (2.60%), wk 28 4571 (2.03%) all AGD and seal predation with some physical damage. Wk 36
1396 (1.55%) all AGD, wk 37 2013 (1.51%), wk 38 2677 (1.16%), fw treatment losses.
Peaks in salmon mortality 2023, wk 35 14017 (1.23%), wk 36 24 989 (2.21%), wk 37 18820 (1.70%), wk 39 15408 (1.39%), wk
40 47228 (4.43%) AGD poor doers.
Salmon mortalities for the last four weeks, wk 44 32,807 (3.72%), wk 43 26590 (2.93%), wk 42 45,333 (4.75%), wk 41 63,864
(6.27%) mainly AGD and treatment losses but also some poor doers.
Peaks in lumpfish mortality 2023, wk 28 12,932 (7.51%), wk 29 28,381 (17.82%) tenacibaculum.
Peaks in wrasse mortality 2023 wk 41 5957 (19.95%) runts and some AGD recorded.
Lumpfish mortality last four weeks, wk45 159 (0.14%), wk 44 166 (0.15%), wk 43 430 (0.39%) wk 42 511 (0.46%).
Wrasse mortality, last four weeks, wk 45 532 (2.27%, wk 44 45 (0.19%), wk 43 214 (0.90%), wk 42 949 (3.86%)
Most recent treatments have included paramove in August and September, freshwater in November, October and September.
Lice numbers are currently low.
Piscirickettsia recently identified, antibiotic treatment is planned.
A number of lethargic and moribund fish observed in all cages.
Some walkways had minor damage following recent storms, these are to be repaired when possible. [Original PDF]