Norway – Environmental services – Titak monitoring of limed salmon water courses in Norway 2025-2029

The assignment includes biological and water chemical monitoring and evaluation of the effect of liming in the salmon water courses. The liming should restore the water quality affected by long-range acid rain to a level that is not damaging for salmon and other species. A central goal is the rebuilding or re-establishing of salmon stock to a level with normal production. The general targets for the liming business are to ensure or reproduce "good ecological condition" in accordance with the water regulations for acidification, and to ensure good accessibility to recreational fishing (harvestable profits) in acidification-stricken areas. In all of the limed water courses, investigations shall be carried out of young fish (field investigation in autumn) and benthic fauna (spring and autumn tests) every second year on a fixed station network. Studies and analyses shall be carried out in accordance with standardised and professionally recognised methodology. Water samples will be taken on a fixed station network at least once a month, which is sent in for water chemical analyses. These analysis results shall be combined and assessed in the monitoring every year. The results of the biological and water chemical surveys are combined and presented in an annual report, in which developments over time are shown (based on previous years results), the goal achievement at the liming is evaluated and the need for changes in the liming strategy is assessed.