The core indicator evaluates average dissolved inorganic nitrogen concentration in the surface (0 – 10 m) during winter (December – February) during the assessment period 2011-2015.
Of the 17 assessed open-sea assessment units, good status has been achieved only in the Gdansk Basin (DIN concentration below defined threshold value, which reflects good conditions).Though the winter-time DIN is still at elevated levels in the remaining 16 sub-basins, it has decreased in the 1990s or the early 2000s and remained since then on the same level.
figure 1: Status assessment results based evaluation of the indicator ‘DIN'.
The assessment is carried out using Scale 4 HELCOM assessment units
(defined in the HELCOM
Monitoring and Assessment Strategy Annex 4).
The confidence of the presented DIN
status estimate is moderate in all 17 open sub-basins. Of all
coastal waters where DIN was assessed, good eutrophication status was only
found in Polish coastal waters and around the Swedish islands in Gotland Basin.
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.
BSAP segment and objectives
Baltic Sea unaffected by eutrophication
D5 Human-induced eutrophication
- D5C1 Nutrient concentrations are not at levels that indicate adverse eutrophication effects
D1 Biological diversity of species and habitats
Theme: Pelagic habitats
-D1C6 The condition of the habitat type, including its biotic and abiotic structure and its functions, is not adversely affected due to anthropogenic pressures.
Theme: Benthic habitats
-D6C5 The extent of adverse effects from anthropogenic pressures on the condition of the habitat type, including alteration to its biotic and abiotic structure and its functions, does not exceed a specified proportion of the natural extent of the benthic habitat type in the assessment area.
Other relevant legislation: EU Water Framework Directive
HELCOM (2017). Dissolved inorganic nitrogen (DIN). HELCOM
core indicator report. Online. [Date Viewed], [Web link].
HOLAS II component - Core indicator report – web-basedversion July 2017 (pdf)