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SUSTAINABILITY LIBRARY 2023 Policies Policy: Algae monitoring

Policy: Algae monitoring

Algae monitoring policy

Owner/Approver: Head of fish health LSG/COO Farming

Valid from: 2022-03-02



Algae naturally occur in Norwegian waters and are an important part of the ecosystem. Certain environmental conditions may result in individual incidences of large algal blooms. The algae may either produce toxins that are harmful to the fish or may be so prevalent that they clog the fish gills. Some algae also have a surface structure that harms the gills. If there is a high density of such algae, the fish will not be able to sustain normal gill function. Proper monitoring of algae incidence is important if we are to implement measures at the right time.

Valid for

This policy applies to all the Group's farming operations.


Algae: Collective term for very different single-cell and multi-cell organisms that have photosynthesis and humid environments as common factors.

Framework and principles

The Institute of Marine Research carries out national monitoring of algae, and their information is available to the public on their website, The industry and authorities continue to take efforts to identify the optimal solution for comparison of data collected by the industry with the results of monitoring by the authorities. The aim is to obtain a better and more comprehensive algae monitoring system.

Lerøy's algae monitoring is based on risk periods and observations that indicate suspected algal bloom. If any findings seem suspicious, all involved parties in the area are notified.

If an algal bloom affects one of our localities, we have a clear plan of action describing what has to be done. Depending on the scope, rapidly implemented measures will help reduce the impact on the fish. In some cases, it may be necessary to clarify with the authorities and other parties whether the fish can be moved from the area affected.

Roles and responsibilities

  • Personnel working with fish health and production at Lerøy are jointly responsible for assessing the level of monitoring and possible measures to combat episodes of algal bloom that affect a locality.
  • The management of the various departments is responsible for policy implementation and updates

Policy ownership and implementation

  • The policy is approved by Head of fish health LSG
  • The policy has been approved by the Corporate Management Group, presented to the Audit Committee and approved by the Board of Directors
  • The COO Farming has the overall responsibility for the policy.