The core indicator evaluates the average concentration in the surface (0 – 10 m) during winter (December – February) during the assessment period 2011-2015.
Of 17 open-sea sub-basins, good status (DIP concentration below defined threshold value, which reflects good conditions) for DIP has been achieved only in the Bothnian Bay.
Of the remaining 16 sub-basins, Kattegat, Great Belt and Kiel Bay are near to the threshold values whereas the remaining basins are still far away from the threshold values. Of all coastal waters that were assessed, good eutrophication status is only found in some areas of the Swedish and Polish coastal waters.
Key message figure 1: Status assessment results based evaluation of the indicator 'DIP'. The assessment is carried out using Scale 4 HELCOM assessment units (defined in the HELCOM Monitoring and Assessment Strategy Annex 4). Use +/- key to zoom.
The confidence of the presented DIP status estimate is moderate in all 17 open sub-basins.
The indicator is applicable in the waters of all countries bordering the Baltic Sea.
Eutrophication is caused by excessive inputs of nutrients (nitrogen and
phosphorus) resulting from various human activities. High concentrations of
nutrients and their ratios form the preconditions for huge algal blooms,
reduced water clarity and increased oxygen consumption. Long-term nutrient data
are key parameters for quantifying the effects of anthropogenic activities and
evaluating the success of measures undertaken.
Baltic Sea unaffected by eutrophication
D5 Human-induced eutrophication
- D5C1 Nutrient concentrations are not at levels that indicate adverse eutrophication effects
HELCOM (2017). Dissolved inorganic phosphorus (DIP). HELCOM
core indicator report. Online. [Date Viewed], [Web link].