Thresholds and Status evaluation

Status evaluation is measured in relation to scientifically based and commonly agreed sub-basin specific threshold values, which define the values that should not be exceeded (Thresholds and Status evaluation figure 1).


Thresholds and Status evaluation figure 1. Schematic representation of the threshold value applied in the water clarity core indicator, the threshold values are assessment unit specific (see Good environmental status table 1).


These indicator threshold values were based on the results obtained in the TARGREV project (HELCOM 2013a), taking also 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 by the intersessional activity on development of core eutrophication indicators (HELCOM CORE EUTRO) and the targets were adopted by the HELCOM Heads of Delegations 39/2012.


Thresholds and Status evaluation table 1. Assessment unit specific threshold values for the water clarity core indicator.

HELCOM_IDAssessment unit (open sea)Threshold value (Secchi depth, m)
SEA-002Great Belt8.5
SEA-003The Sound8.2
SEA-004Kiel Bay7.4
SEA-005Bay of Mecklenburg7.1
SEA-006Arkona Sea7.2
SEA-007Bornholm Sea7.1
SEA-008Eastern Gotland Basin7.6
SEA-009Gdansk Basin6.5
SEA-010Western Gotland Basin8.4
SEA-011Northern Baltic Proper7.1
SEA-012Gulf of Riga5.0
SEA-013Gulf of Finland5.5
SEA-014Ă…land Sea6.9
SEA-015Bothnian Sea6.8
SEA-016The Quark6.0
SEA-017Bothnian Bay5.8