Trettholmosen

Site 32857 · Bømlo municipality · Production area 3, Karmøy til Sotra

Below the lice limit, week 39Operated by Seashore Sjø AS · group unknown

0.16Adult female lice per fishLimit 0.50 · below the limitWeek 39, 2026 · Norwegian Food Safety Authority · updated 01 Oct 2026

1Weeks above the limit in 2026of 14 weeks with a countCalculated by the Salmon Ledger · Norwegian Food Safety Authority · updated 01 Oct 2026

2Lice treatments in 2026Latest: Mechanical delousing, week 39, 20262026 · Norwegian Food Safety Authority · updated 01 Oct 2026

0Active disease casesNone recordedRegister since 26 Nov 2024 · Norwegian Food Safety Authority · updated 01 Oct 2026

4Wellboat visits in 2026by 2 different vessels · latest 13 Aug 2026Derived from AIS · Norwegian Coastal Administration (AIS) · updated 01 Oct 2026

0Escapes reportedNone reportedSince 2006 · Directorate of Fisheries · updated 01 Oct 2026

Sea lice against the limit

Weekly average of adult female lice per fish, as reported by the company. For this site the limit is 0.2 in weeks 16–21 and 0.5 for the rest of the year. Hatched weeks have no count and count neither as above nor below.

2026

Source: Norwegian Food Safety Authority, weekly lice counts reported by the companies · Limit: Regulation on sea lice control § 8 · Updated 01 Oct 2026

Show as table

Adult female lice per fish per week, 2026
Week	Adult female lice per fish	Lice limit	Status
1	unknown	0.5	Not reported
2	unknown	0.5	Not reported
3	unknown	0.5	Not reported
4	unknown	0.5	Not reported
5	unknown	0.5	Not reported
6	unknown	0.5	Not reported
7	unknown	0.5	Not reported
8	unknown	0.5	Not reported
9	unknown	0.5	Not reported
10	unknown	0.5	Not reported
11	unknown	0.5	Not reported
12	unknown	0.5	Not reported
13	unknown	0.5	Not reported
14	unknown	0.5	Not reported
15	unknown	0.5	Not reported
16	unknown	0.2	Not reported
17	unknown	0.2	Not reported
18	unknown	0.2	Not reported
19	unknown	0.2	Not reported
20	unknown	0.2	Not reported
21	unknown	0.2	Not reported
22	unknown	0.5	Not reported
23	unknown	0.5	Not reported
24	unknown	0.5	Not reported
25	unknown	0.5	Not reported
26	0.00	0.5	Below the limit
27	0.00	0.5	Below the limit
28	0.00	0.5	Below the limit
29	0.00	0.5	Below the limit
30	0.03	0.5	Below the limit
31	0.18	0.5	Below the limit
32	0.45	0.5	Near the limit
33	0.03	0.5	Below the limit
34	0.02	0.5	Below the limit
35	0.05	0.5	Below the limit
36	0.05	0.5	Below the limit
37	0.20	0.5	Below the limit
38	0.57	0.5	Above the limit
39	0.16	0.5	Below the limit

Earlier years

20255 of 35 weeks with a count above the limit

Source: Norwegian Food Safety Authority, weekly lice counts reported by the companies · Limit: Regulation on sea lice control § 8 · Updated 01 Oct 2026

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Adult female lice per fish per week, 2025
Week	Adult female lice per fish	Lice limit	Status
1	0.48	0.5	Near the limit
2	0.14	0.5	Below the limit
3	0.03	0.5	Below the limit
4	0.02	0.5	Below the limit
5	0.03	0.5	Below the limit
6	0.04	0.5	Below the limit
7	0.05	0.5	Below the limit
8	0.10	0.5	Below the limit
9	0.20	0.5	Below the limit
10	0.18	0.5	Below the limit
11	0.21	0.5	Below the limit
12	0.33	0.5	Below the limit
13	0.08	0.5	Below the limit
14	0.11	0.5	Below the limit
15	0.17	0.5	Below the limit
16	0.22	0.2	Above the limit
17	0.01	0.2	Below the limit
18	0.06	0.2	Below the limit
19	0.06	0.2	Below the limit
20	0.04	0.2	Below the limit
21	0.19	0.2	Near the limit
22	0.29	0.5	Below the limit
23	0.65	0.5	Above the limit
24	0.10	0.5	Below the limit
25	0.02	0.5	Below the limit
26	0.04	0.5	Below the limit
27	0.07	0.5	Below the limit
28	0.49	0.5	Near the limit
29	0.29	0.5	Below the limit
30	0.49	0.5	Near the limit
31	0.30	0.5	Below the limit
32	0.68	0.5	Above the limit
33	4.47	0.5	Above the limit
34	3.44	0.5	Above the limit
35	0.27	0.5	Below the limit
36	unknown	0.5	Reported without a count
37	unknown	0.5	Not reported
38	unknown	0.5	Not reported
39	unknown	0.5	Not reported
40	unknown	0.5	Not reported
41	unknown	0.5	Not reported
42	unknown	0.5	Not reported
43	unknown	0.5	Not reported
44	unknown	0.5	Not reported
45	unknown	0.5	Not reported
46	unknown	0.5	Not reported
47	unknown	0.5	Not reported
48	unknown	0.5	Not reported
49	unknown	0.5	Not reported
50	unknown	0.5	Not reported
51	unknown	0.5	Not reported
52	unknown	0.5	Not reported

20240 of 12 weeks with a count above the limit

Source: Norwegian Food Safety Authority, weekly lice counts reported by the companies · Limit: Regulation on sea lice control § 8 · Updated 01 Oct 2026

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Adult female lice per fish per week, 2024
Week	Adult female lice per fish	Lice limit	Status
1	unknown	0.5	Not reported
2	unknown	0.5	Not reported
3	unknown	0.5	Not reported
4	unknown	0.5	Not reported
5	unknown	0.5	Not reported
6	unknown	0.5	Not reported
7	unknown	0.5	Not reported
8	unknown	0.5	Not reported
9	unknown	0.5	Not reported
10	unknown	0.5	Not reported
11	unknown	0.5	Not reported
12	unknown	0.5	Not reported
13	unknown	0.5	Not reported
14	unknown	0.5	Not reported
15	unknown	0.5	Not reported
16	unknown	0.2	Not reported
17	unknown	0.2	Not reported
18	unknown	0.2	Not reported
19	unknown	0.2	Not reported
20	unknown	0.2	Not reported
21	unknown	0.2	Not reported
22	unknown	0.5	Not reported
23	unknown	0.5	Not reported
24	unknown	0.5	Not reported
25	unknown	0.5	Not reported
26	unknown	0.5	Not reported
27	unknown	0.5	Not reported
28	unknown	0.5	Not reported
29	unknown	0.5	Not reported
30	unknown	0.5	Not reported
31	unknown	0.5	Not reported
32	unknown	0.5	Not reported
33	unknown	0.5	Not reported
34	unknown	0.5	Not reported
35	unknown	0.5	Not reported
36	unknown	0.5	Not reported
37	unknown	0.5	Not reported
38	unknown	0.5	Not reported
39	unknown	0.5	Not reported
40	unknown	0.5	Reported without a count
41	0.00	0.5	Below the limit
42	0.00	0.5	Below the limit
43	0.00	0.5	Below the limit
44	0.00	0.5	Below the limit
45	0.15	0.5	Below the limit
46	0.21	0.5	Below the limit
47	0.22	0.5	Below the limit
48	0.24	0.5	Below the limit
49	0.17	0.5	Below the limit
50	0.26	0.5	Below the limit
51	0.30	0.5	Below the limit
52	0.37	0.5	Below the limit

Treatments

Norwegian Food Safety Authority

Week 39, 2026
Mechanical delousingWhole site
Week 33, 2026
Thermal delousingWhole site
Week 34, 2025
Other treatment1 pen · Freshtherm
Week 29, 2025
Mechanical delousing2 pens

Show all 9

Week 24, 2025
Other treatmentWhole site · Freshtherm
Week 17, 2025
Mechanical delousingWhole site
Week 13, 2025
Medicinal bath1 pen · Azamethiphos
Week 12, 2025
Medicinal bath3 pens · Azamethiphos
Week 2, 2025
Freshwater treatment, Other treatmentWhole site · Freshtherm

Disease

Norwegian Food Safety Authority

No cases in the Food Safety Authority's register of notifiable diseases (since 26 Nov 2024).

Escapes

Directorate of Fisheries

No escapes reported from this site since 2006.

Wellboat visits

4 visits in 2026

Visits are derived by us from the Coastal Administration's AIS positions: a fish carrier stationary within 500 metres of the farm for at least 30 minutes. The AIS archive lags about 17 days. A visit is not proof of infection.

Arrival	Vessel	Previous farm (14 days)	Duration
13 Aug 2026	Ronja Vest	Breivik S	6 h 59 min
11 Aug 2026	Ronja Vest	Breivik S	27 h 22 min
26 Jun 2026	Ronja Queen	Holevik	4 h 5 min
25 Jun 2026	Ronja Queen	Holevik	2 h 11 min
31 Aug 2025	Ronja Queen	Svollandsneset	4 h 10 min
27 Aug 2025	Ronja Queen	Øklandsvågen	2 h 58 min
26 Aug 2025	Ronja Queen	Øklandsvågen	3 h 46 min
25 Aug 2025	Ronja Queen	Øklandsvågen	1 h 58 min
24 Aug 2025	Ronja Vest	Hattasteinen	4 h 30 min
23 Aug 2025	Ronja Vest	Hattasteinen	15 h 39 min
31 Jul 2025	Namsos	Langevågen	3 h 7 min
28 Jul 2025	Namsos	Langevågen	1 h 33 min

Show 19 older visits

Arrival	Vessel	Previous farm (14 days)	Duration
24 Jul 2025	Ronja Vest	Øklandsvågen	3 h 32 min
20 Jul 2025	Ronja Queen	Øklandsvågen	11 h 13 min
18 Jul 2025	Ronja Queen	Øklandsvågen	41 h 58 min
17 Jul 2025	Ronja Queen	Øklandsvågen	12 h 53 min
14 Jun 2025	Ronja Vest	no other farm	11 h 53 min
23 Apr 2025	Ronja Queen	Øklandsvågen	4 h 45 min
22 Apr 2025	Ronja Queen	Øklandsvågen	11 h 49 min
24 Mar 2025	Ronja Vest	Jørstadskjera	2 h 13 min
24 Mar 2025	Ronja Vest	Jørstadskjera	4 h 40 min
23 Mar 2025	Ronja Vest	Jørstadskjera	5 h 9 min
23 Mar 2025	Ronja Vest	Jørstadskjera	6 h 40 min
22 Mar 2025	Ronja Vest	Jørstadskjera	3 h 21 min
12 Jan 2025	Ronja Vest	Lyngnes	2 h 46 min
06 Jan 2025	Navoey	Gissøysundet S	44 min
03 Nov 2024	Ronja Mistral	Brottøy	3 h 54 min
03 Nov 2024	Navoey	no other farm	2 h 42 min
02 Nov 2024	Ronja Mistral	Brottøy	3 h 8 min
04 Oct 2024	Ronja Mistral	Ommundsteigen	2 h 7 min
03 Oct 2024	Ronja Mistral	Ommundsteigen	2 h 33 min

Source: Norwegian Coastal Administration (AIS) · calculated by the Salmon Ledger · updated 01 Oct 2026

Licences

Site MAB: 2,340 tonnes

Licence	Type	Capacity	Holder
H B 0002	Kommersiell / matfiskSalmon, Rainbow trout, Trout	689 t	Seashore Sjø AS
H B 0005	Kommersiell / matfiskSalmon, Rainbow trout, Trout	4,825 t	Seashore Sjø AS
H B 0012	Kommersiell / matfiskSalmon, Rainbow trout, Trout	689 t	Seashore Sjø AS
H B 0022	Kommersiell / matfiskSalmon, Rainbow trout, Trout	689 t	Seashore Sjø AS
H B 0036	Kommersiell / matfiskSalmon, Rainbow trout, Trout	689 t	Seashore Sjø AS
H FS 0037	Kommersiell / matfiskSalmon, Rainbow trout, Trout	750 t	Bolaks Sjø AS

Source: Directorate of Fisheries, aquaculture register · updated 01 Oct 2026