Baltic Marine Environment
Protection Commission

Nutrient Reduction Scheme

The HELCOM Nutrient Reduction Scheme is a regional approach to sharing the burden of nutrient reductions to achieve the goal of a Baltic Sea unaffected by eutrophication agreed by the Baltic Sea countries. 

The Scheme has been introduced and agreed first in 2007, in the HELCOM Baltic Sea Action Plan. At that time, the countries agreed on provisional nutrient reduction targets and decided that the figures will be revised using a harmonised approach and most updated data as well enhanced modelling. The revision process started in 2008 and was completed in 2013.

There are three main components of the nutrient reduction scheme:

  • Country-Allocated Reduction Targets (CART), indicating how much nutrient inputs the HELCOM countries need to reduce comparing to a reference period (1997-2003).
  • Maximum Allowable Inputs (MAI) of nutrients, indicating the maximal level of inputs of water- and airborne nitrogen and phosphorus to Baltic Sea sub-basins that can be allowed to fulfill the targets for non-eutrophied sea;
  • Nutrient Input Ceilings (NIC), indicating the maximum allowable inputs of nutrients for each country to each sub-basin of the Baltic Sea.


The targets on nutrient inputs and nutrient reduction scheme of the HELCOM Baltic Sea Action Plan was revised in the 2013 HELCOM Ministerial Meeting, based on a new and more complete dataset as well as an improved modelling approach.


Maximum Allowable Inputs (MAI) indicate the maximal level of total (water- and airborne) input of nitrogen and phosphorus to the Baltic Sea sub-basins that is allowed to fulfil the targets for the sea unaffected by eutrophication. 


Nutrient input ceilings (NIC) indicate maximum allowable inputs of nutrients for each country to each sub-basin of the Baltic Sea, integrating the inputs of waterborne, airborne and transboundary sources (via rivers through another country). 

HELCOM estimated in 2007 that for good environmental status to be achieved, the maximum allowable annual nutrient pollution inputs into the Baltic Sea would be 21,000 tonnes of phosphorus and about 600,000 tonnes of nitrogen. Annual reductions of some 15,000 tonnes of phosphorus and 135,000 tonnes of nitrogen would be required to reach to achieve the plan’s crucial “clear water” objective.

The HELCOM Ministerial Meeting 2013 in Copenhagen adopted the revised HELCOM nutrient reduction scheme.