Trettevik

Site 17077 · Senja municipality · Production area 10, Andøya til Senja

Below the lice limit, week 39Operated by Salmar Oppdrett AS · group SalMar

0.00Adult female lice per fishLimit 0.50 · below the limitWeek 39, 2026 · Norwegian Food Safety Authority · updated 01 Oct 2026

0Weeks above the limit in 2026of 7 weeks with a countCalculated by the Salmon Ledger · Norwegian Food Safety Authority · updated 01 Oct 2026

0Lice treatments in 2026None recorded2026 · Norwegian Food Safety Authority · updated 01 Oct 2026

1Active disease casesILA, confirmed 19 Jun 2025Register since 26 Nov 2024 · Norwegian Food Safety Authority · updated 01 Oct 2026

2Wellboat visits in 2026by 1 vessel · latest 18 Aug 2026Derived from AIS · Norwegian Coastal Administration (AIS) · updated 01 Oct 2026

2Escapes reported2,028 salmon, December 2019Since 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 21–26 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

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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	0.5	Not reported
17	unknown	0.5	Not reported
18	unknown	0.5	Not reported
19	unknown	0.5	Not reported
20	unknown	0.5	Not reported
21	unknown	0.2	Not reported
22	unknown	0.2	Not reported
23	unknown	0.2	Not reported
24	unknown	0.2	Not reported
25	unknown	0.2	Not reported
26	unknown	0.2	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	0.00	0.5	Below the limit
34	0.00	0.5	Below the limit
35	0.00	0.5	Below the limit
36	0.00	0.5	Below the limit
37	0.00	0.5	Below the limit
38	0.00	0.5	Below the limit
39	0.00	0.5	Below the limit

Earlier years

20250 of 27 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	0.08	0.5	Below the limit
2	0.09	0.5	Below the limit
3	0.11	0.5	Below the limit
4	0.10	0.5	Below the limit
5	0.12	0.5	Below the limit
6	0.12	0.5	Below the limit
7	0.08	0.5	Below the limit
8	0.19	0.5	Below the limit
9	0.12	0.5	Below the limit
10	0.17	0.5	Below the limit
11	0.19	0.5	Below the limit
12	0.19	0.5	Below the limit
13	0.15	0.5	Below the limit
14	0.17	0.5	Below the limit
15	0.16	0.5	Below the limit
16	0.25	0.5	Below the limit
17	0.19	0.5	Below the limit
18	0.18	0.5	Below the limit
19	0.07	0.5	Below the limit
20	0.05	0.5	Below the limit
21	0.06	0.2	Below the limit
22	0.03	0.2	Below the limit
23	0.07	0.2	Below the limit
24	0.04	0.2	Below the limit
25	0.10	0.2	Below the limit
26	0.12	0.2	Below the limit
27	0.12	0.5	Below the limit
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	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 41 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	0.24	0.5	Below the limit
2	0.36	0.5	Below the limit
3	0.41	0.5	Near the limit
4	0.17	0.5	Below the limit
5	0.20	0.5	Below the limit
6	0.31	0.5	Below the limit
7	0.39	0.5	Below the limit
8	0.27	0.5	Below the limit
9	0.33	0.5	Below the limit
10	0.23	0.5	Below the limit
11	0.28	0.5	Below the limit
12	0.22	0.5	Below the limit
13	0.23	0.5	Below the limit
14	0.21	0.5	Below the limit
15	0.27	0.5	Below the limit
16	0.26	0.5	Below the limit
17	0.43	0.5	Near the limit
18	0.21	0.5	Below the limit
19	0.29	0.5	Below the limit
20	0.28	0.5	Below the limit
21	0.17	0.2	Near the limit
22	0.18	0.2	Near the limit
23	0.18	0.2	Near the limit
24	unknown	0.2	Not reported
25	unknown	0.2	Reported without a count
26	unknown	0.2	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	0.00	0.5	Below the limit
36	0.00	0.5	Below the limit
37	0.00	0.5	Below the limit
38	0.00	0.5	Below the limit
39	0.00	0.5	Below the limit
40	0.01	0.5	Below the limit
41	0.04	0.5	Below the limit
42	0.01	0.5	Below the limit
43	0.01	0.5	Below the limit
44	0.03	0.5	Below the limit
45	0.02	0.5	Below the limit
46	0.02	0.5	Below the limit
47	0.10	0.5	Below the limit
48	0.18	0.5	Below the limit
49	0.16	0.5	Below the limit
50	0.18	0.5	Below the limit
51	0.07	0.5	Below the limit
52	0.06	0.5	Below the limit

20230 of 13 weeks with a count above the limit (data from week 40)

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, 2023
Week	Adult female lice per fish	Lice limit	Status
40	0.43	0.5	Near the limit
41	0.15	0.5	Below the limit
42	0.31	0.5	Below the limit
43	0.21	0.5	Below the limit
44	0.11	0.5	Below the limit
45	0.27	0.5	Below the limit
46	0.30	0.5	Below the limit
47	0.43	0.5	Near the limit
48	0.34	0.5	Below the limit
49	0.43	0.5	Near the limit
50	0.37	0.5	Below the limit
51	0.41	0.5	Near the limit
52	0.47	0.5	Near the limit

Treatments

Norwegian Food Safety Authority

Week 19, 2025
Mechanical delousing6 pens
Week 51, 2024
Mechanical delousing5 pens
Week 45, 2024
Medicinal feed4 pens · Emamectin benzoat
Week 38, 2024
Medicinal feedWhole site · Emamectin benzoat

Show all 9

Week 4, 2024
Other treatment2 pens · Thermolicer
Week 50, 2023
Other treatment2 pens · Optiflush
Week 44, 2023
Other treatment6 pens · Optiflush
Week 41, 2023
Other treatment5 pens · Hydrolicer
Week 40, 2023
Other treatment5 pens · Hydrolicer, Optiflush

Disease

Norwegian Food Safety Authority

19 Jun 2025
Infectious salmon anaemia (ISA): confirmedStatus: active · started 13 Jun 2025 · Norwegian Food Safety Authority

Escapes

Directorate of Fisheries

03 Dec 2019
2,028 salmon escapedrecaptured 1 · Directorate of Fisheries
03 Aug 2018
1 salmon escapedCause: Håndtering · recaptured 1 · Directorate of Fisheries

Wellboat visits

2 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
18 Aug 2026	Ronja Aurora	Brensholmen	1 h 58 min
15 Aug 2026	Ronja Aurora	Tristeinen	1 h 57 min
09 May 2025	Ro Fortune	Finnvik	21 h 2 min
20 Dec 2024	Ro Arctic	Skårliodden	5 h 31 min
19 Dec 2024	Ro Arctic	Skårliodden	34 h 46 min
22 Oct 2024	Ronja Aurora	Finnvika S	2 h 56 min
15 Oct 2024	Ronja Aurora	Olaneset	4 h 42 min
03 Sep 2024	Ronja Aurora	Hjortholman	7 h 44 min
01 Sep 2024	Ronja Vita	Takflua	6 h 3 min
24 Aug 2024	Ronja Aurora	Hjortholman	2 h 57 min
21 Jun 2024	Ro Sailor	Reinvika	2 h 48 min
20 Jun 2024	Ro Fortune	Vengsøy	2 h 34 min

Show 4 older visits

Arrival	Vessel	Previous farm (14 days)	Duration
14 Jun 2024	Ro Sailor	Latvika	1 h 29 min
29 May 2024	Froy Odin	Klubben	3 h 5 min
27 May 2024	Froy Odin	Klubben	5 h 35 min
24 Jan 2024	Ro Arctic	Fellesholmen	12 h 36 min

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

Licences

Site MAB: 10,000 tonnes

Licence	Type	Capacity	Holder
T D 0009	Kommersiell / matfiskSalmon, Rainbow trout, Trout	1,022 t	Salmar Oppdrett AS
T D 0010	Kommersiell / matfiskSalmon, Rainbow trout, Trout	1,022 t	Salmar Oppdrett AS
T D 0011	Kommersiell / matfiskSalmon, Rainbow trout, Trout	1,022 t	Salmar Oppdrett AS
T D 0012	Kommersiell / matfiskSalmon, Rainbow trout, Trout	1,022 t	Salmar Oppdrett AS
T D 0013	Kommersiell / matfisk-grønn bSalmon, Rainbow trout, Trout	974 t	Salmar Oppdrett AS
T G 0008	Kommersiell / matfiskSalmon, Rainbow trout, Trout	1,021 t	Salmar Oppdrett AS
T TN 0001	Kommersiell / matfiskSalmon, Rainbow trout, Trout	1,021 t	Salmar Oppdrett AS
T TN 0005	Kommersiell / matfiskSalmon, Rainbow trout, Trout	1,021 t	Salmar Oppdrett AS

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