Protect our oceans


Before stocking a production site, approval is required from a number of official and private bodies. Furthermore, approval requires compliance with numerous analyses, requirements and local conditions.

These approvals are given after mapping and compliance of ecological status, spawning areas for marine species, diversity, and presence of endangered species in the region.

One of the assessments carried out both prior to approval for operations at a location and during fish farming at the facility is a MOM-B evaluation.

MOM-B stands for:

M – matfiskanlegg (production facility)

O – overvåkning (monitoring)

M – modellering (modelling)


A MOM-B evaluation is carried out by an independent third party body and involves extraction of samples from the seabed under and close to the cages in a facility.

The analysis has three components:

  • Fauna investigation
  • Chemical investigation (pH and oxidation reduction potential)
  • Sensory investigation (gas, color, odor, consistency, dredge volume and mud depth)

All parameters are allocated a score depending of how much the sea bed is affected by the organic  substance. The distinction between acceptable and  unacceptable sediment condition is set to the highest  accumulation that allows burrowing benthic organisms  to live in the sediment.

On the basis of these investigations, the individual location receives a score, which also provides an indication of when the next MOM-B investigation should be carried out. A poor score often requires more frequent seabed investigations than a good  score. In addition to MOM-B, analyses are also conducted locally at individual facilities. These include measurement of density, oxygen level in the sea, currents, water quality, visibility, dives etc.

Each facility is also linked with neighboring  facilities in a zone-based cooperation to work together on topics such as lice and preventing accidental release, prevent spread of disease, prevent outbreaks of disease etc.

MAIN GOAL: Average MOM-B max 1.5 per location (average score all surveys in calendar year for locations in operation that year)

KPI (2022): MOM-B score within 1 or 2 for all locations


The Group also conduct MOM C surveys. The C-survey is a trend monitoring of the bottom conditions in the transition zones from the farming zone and outwards in the recipient. This study is based on mapping of fauna on soft bottoms, which is carried out in accordance with relevant ISO standards.

In addition, hydrographic, geological and chemical support parameters are included. These extended trend monitoring outside the local areas is done as often as required, depending of environmental conditions, standard criteria and permit terms.

KPI: Biodiversity


Copper is a naturally occurring chemical element which can be toxic at high levels in the marine environment. Nets can be treated with antifouling agents containing copper. Also, cleaning of nets during the production cycle is necessary to ensure good water quality for the farmed  fish. Lerøy Seafood Group uses low-pressure underwater washers to reduse copper release to the environment.

Together with suppliers, the Group works to identify alternative antifouling products and alternative net materials. Such alternative solutions are now in our “tool-box” for managing nets, and are implemented in the Group´s production strategies.

In addition to cleaning in-situ, all nets are cleaned at onshore sites after each production period. Onshore cleaning sites have zero copper emissions, as required  by Norwegian legislation.

MAIN GOAL: Replace antifouling agents that contain copper


As a strategy to minimize infection pressure and environmental impact, all sites are fallowed and washed/disinfected every two years. In all regions where the Group has operations, fallowing and  stocking periods are coordinated in zones, defined by the The Norwegian Food Safety Authority, NFSA and companies in each Area Based Management, ABM scheme.

Every site in a defined coordinated area is fallowed every second year for at least two  months. Within each area-based management area, there is at least a one-month coordinated fallowing period every second year.

In 2021, every marine site was fallowed for more than four months (142 days) on average for the Group.

MAIN GOAL: Average fallowing per location: Minimum 60 days


Fallowed days in average per site

Year Lerøy Aurora Lerøy Midt Lerøy Sjøtroll Total
2021 135 153 139 142
2020 134  122  161  138
2019 227  121 126 140
2018 123 158 135 138
2017 92 204 125 132
2016 111 179 123 141
2015 84 94 120 105
2014 95 84 134 107


The maximum legislative limit for fish density in a seacage is 25 kg/m3. Average density in the Group´s cages is far below this, indicating that the fish have plenty of space in the cages. In 2021, the average density for the Group´s seafarms was 8,7 kg/m3.

Fish health and fish welfare are at the core of our operations as a producer of Atlantic salmon and rainbow trout. As such, we are committed to both ethical and statutory obligations governed by Norwegian legislation.

A healthy fish is also a good fish for production and a prerequisite for good financial results. There are therefore numerous incentives for putting fish health and fish welfare at the top of the agenda for fish-farming operations. In an effort to ensure that we continuously fulfill these obligations, the Group has chosen to invest substantial resources in preventive measures for fish health, and this is a major part of the production strategy for the entire Group.

MAIN GOAL DENSITY: Less than 25 kg/m3


Row labels Lerøy Aurora Lerøy Midt Lerøy Sjøtroll Grand Total


Jan.2021                    8,6                   9,4                     8,7                   8,9
Feb.2021                    8,8                   9,4                     8,6                   9,0
Mar.2021                    8,9                   9,4                     7,8                   8,6
Apr.2021                    8,5                   9,3                     7,1                   8,1
Mai.2021                    7,4                10,0                     7,2                   8,2
Jun.2021                    8,3                   9,9                     7,3                   8,4
Jul.2021                    8,6                   9,5                     8,1                   8,7
Aug.2021                    9,1                   9,2                     8,1                   8,7
Sep.2021                    8,8                   9,5                     8,5                   8,9
Okt.2021                    9,2                10,0                     8,5                   9,2
Nov.2021                    7,6                   9,5                     8,8                   8,7
Des.2021                    7,0                   9,7                     8,9                   8,7
Grand Total                    7,0                   9,7                     8,9                   8,7

We care about the welfare our fish and accept our ethical responsibility that comes with animal farming. The Group's goal is qualitative and requires continuous monitoring and targeted efforts throughout our farming value chain.