Status evaluation is measured in relation to scientifically based and commonly agreed sub-basin specific threshold value, which defines the concentration that should not be exceeded (Thresholds figure 1).
Thresholds figure 1. Schematic representation of the threshold values applied in the DIN core indicator, the threshold values are assessment unit specific (see Thresholds table 1).
These indicator threshold values were based on the results obtained in the TARGREV project (HELCOM 2013a), also taking advantage of the work carried out during the EUTRO PRO process (HELCOM 2009) and national work for EU WFD. The final threshold values were set through an expert evaluation process done via intersessional activity to develop core eutrophication indicators (HELCOM CORE EUTRO), and the threshold values were adopted by the HELCOM Heads of Delegations 39/2012.
Thresholds table 1. Assessment unit specific threshold values for the DIN core indicator.