Calculation of nutrient input ceilings

How have nutrient input ceilings been calculated? 

Nutrient input ceilings are readily calculated by subtracting the reduction requirements (CART) in the 2013 Ministerial Declaration from the net nutrient inputs of each country and basin in the reference period 1997-2003. 

Following the same procedure, nutrient input ceilings can also be assigned to shipping and other sources of airborne inputs. 

The sum of all nutrient input ceilings for a basin will be equal to MAI to that basin (Tables 4a and b).

The necessary information for this calculation was included in the background document for the 2013 Ministerial Meeting. However, detailed information was not provided for calculating the nutrient input ceiling for the basin and nutrient combinations which do not have a reduction requirement. For phosphorus, the nutrient input ceiling in these basins is simply equal to the net inputs in the reference period, but for airborne nitrogen inputs reductions due to implementation of Gothenburg protocol and regulations on shipping emissions were taking into account in the 2013 Ministerial Declaration (see Background document) also for the basins without nitrogen reduction requirements. Thus, in order to meet the requirement that achieving the nutrient input ceiling should result in MAI for these basins, the nutrient input ceiling will be slightly larger than reference inputs for the HELCOM Contracting Parties.

Table 4a: 
Nutrient input ceilings for nitrogen for all basins and countries.

Table 4b: 
Nutrient input ceilings​ for phosphorus for all basins and countries

BOB = Bothnian Bay
BOS = Bothnian Sea
BAP = Baltic Proper
GUF = Gulf of Finland
GUR = Gulf of Riga
DS = Danish Straights
KAT = Kattegat