Personal tools

Subscriptions
Sign up to receive our reports (print and/or electronic) and quarterly e-newsletter.
Follow us
Twitter icon Twitter
Facebook icon Facebook
YouTube icon YouTube channel
RSS logo RSS Feeds
More

Write to us Write to us

For the public:


For media and journalists:

Contact EEA staff
Contact the web team
FAQ

Call us Call us

Reception:

Phone: (+45) 33 36 71 00
Fax: (+45) 33 36 71 99


next
previous
items

Skip to content. | Skip to navigation

Sound and independent information
on the environment

You are here: Home / Data and maps / Indicators / Nutrients in transitional, coastal and marine waters / Nutrients in transitional, coastal and marine waters (CSI 021) - Assessment published Mar 2013

Nutrients in transitional, coastal and marine waters (CSI 021) - Assessment published Mar 2013

Topics: , ,

Generic metadata

Topics:

Water Water (Primary topic)

Coasts and seas Coasts and seas

Tags:
soer2010 | csi | marine and coastal | nutrients | orthophosphate | water | nitrogen | phosphates | thematic assessments | marine
DPSIR: State
Typology: Descriptive indicator (Type A - What is happening to the environment and to humans?)
Indicator codes
  • CSI 021
Dynamic
Temporal coverage:
1985-2010
 
Contents
 

Key policy question: Are nutrient concentrations in our surface waters decreasing?

Key messages

  • In 2010, the highest concentrations of oxidized nitrogen were found in the Baltic Sea, in the Gulf of Riga and Kiel Bay, and in Belgian, Dutch and German coastal waters in the Greater North Sea. Reported stations in the Northern Spanish and Croatian coastal waters also showed high concentration levels. The highest orthophosphate concentrations were found in the Baltic Sea, in the Gulf of Riga and Kiel Bay, and in Irish, Belgian, Dutch and German coastal waters in the Greater North Sea. Coastal stations along Northern Spain and Southern France also showed high concentration levels.
  • Between 1985 and 2010, overall nutrient concentrations have been either stable or decreasing in stations reported to the EEA in the Greater North Sea, Celtic Seas and in the Baltic Sea. However, this decrease has been more pronounced for nitrogen. Assessments for the overall Mediterranean and Black Sea regions were not possible, data only being available for stations in France and Croatia. 
  • For oxidized nitrogen concentrations, 14% of all the reported stations showed decreasing trends, whereas only 2% showed increasing trends. Decreases were most evident in the Baltic Sea (coastal waters of Germany, Denmark, Sweden and Finland, and open waters) and in southern part of the coast of the Greater North Sea. Increasing trends were mainly found in Croatian coastal stations. 
  • For orthophosphate concentrations, 10% of all the reported stations showed a decrease. This was most evident in coastal and open water stations in the Greater North Sea, and in coastal stations in the Baltic Sea. Increasing orthophosphate trends, observed in 6% of the reported stations, were mainly detected in Irish, Danish and Finnish coastal waters (Gulf of Finland and Gulf of Bothnia) and in open waters of the Baltic Proper.

Winter oxidized nitrogen (NO2 + NO3) concentrations in European seas in 2010

Note: The map shows the winter oxidized nitrogen concentrations in the European coastal and open waters in 2010. The low category refers to values within the lowest 20th percentile and the high category refers to values within the upper 20th percentile of concentrations in a regional sea

Data source:
Downloads and more info

Winter orthophosphate concentrations in European seas in 2010

Note: The map shows the winter orthophosphate concentrations in the European coastal and open waters in 2010. The low category refers to values within the lowest 20th percentile and the high category refers to values within the upper 20th percentile of concentrations in a regional sea.

Data source:
Downloads and more info

Trend in winter orthophosphate concentrations in coastal and open waters of the Baltic, North East Atlantic (Greater North Sea, Celtic Seas, Bay of Biscay), and Mediterranean Sea (Western Mediterranean Sea, Adriatic Sea), 1985 - 2010

Note: The figure shows trend in winter orthophosphate concentrations in coastal and open waters of the Baltic, North East Atlantic (Greater North Sea, Celtic Seas, Bay of Biscay), and Mediterranean Sea (Western Mediterranean Sea, Adriatic Sea) (% of stations showing a statistically significant change within the period 1985-2010). Numbers in parentheses indicate the number of stations included in the analysis for each country. "Open sea" is the total of all off-shore stations (>20km) within a (sub)region.

Data source:
Downloads and more info

Observed changes in winter oxidised nitrogen (NO2 and NO3) concentrations, 1985–2010

Note: The map shows stations with a statistically significant decrease (green), increase (red) or no trend (yellow) in winter oxidised nitrogen concentrations within the period 1985-2010. Selected stations must have at least data in the period from 2007 to present and at least 5 years data in all.

Data source:
Downloads and more info

Observed changes in winter orthophosphate (PO4) concentrations, 1985–2010

Note: The map shows stations with a statistically significant decrease (green), increase (red) or no trend (yellow) in winter ortophosphate concentrationswithin the period 1985-2010. Selected stations must have at least data in the period from 2007 to present and at least 5 years data in all.

Data source:
Downloads and more info

Key assessment

Baltic Sea

In 2010, the highest oxidized nitrogen (nitrate+nitrite) concentrations (> 8.7 µmol/l) and orthophosphate concentrations (> 0.76 µmol/l) were predominantly observed in coastal waters, such as in the Gulf of Finland, Gulf of Bothnia, Lithuanian coastal waters, Gulf of Gdansk and the southern coastal waters of the Bornholm Basin (Figures 1 and 2). Low concentrations of nitrogen (< 3.7 µmol/l) were measured mostly in the southern Baltic Sea, whereas low phosphate concentrations (< 0.32 µmol/l) were commonly observed in the Bothnian Bay. 

Between 1985 and 2010, oxidised nitrogen concentrations decreased in 19% of the monitoring stations in the Baltic Sea and increased in 3% of the stations (Figure 3). Decreasing trends were detected especially in the open waters of the Gulf of Bothnia, Baltic Proper, Germany and Denmark (Figure 5), whereas the only increasing trend for this regional sea was observed within coastal waters of Finland.

Orthophosphate concentrations decreased in 5% of the stations and increased in 10% of the stations (Figure 4). Increasing orthophosphate trends were mainly detected in Finnish coastal waters (Gulf of Finland and Gulf of Bothnia) and in open waters of the Baltic Proper. Decreasing trends were observed mainly in Lithuanian and German coastal waters (Figure 6).

Greater North Sea

In the Greater North Sea, the highest winter oxidized nitrogen concentrations (> 46.4 µmol/l) and orthophosphate concentrations (> 1.31 µmol/l) in 2010 were observed in Belgian, Dutch and German transitional and coastal waters (Figures 1 & 2). 

Long term time series indicate that oxidized nitrogen decreased in 13% of the stations (Figure 3), and orthophosphate concentrations decreased in 28% of the Greater North Sea stations (Figure 4). None of the stations showed an increasing trend in oxidized nitrogen, and only two stations showed an increasing trend in orthophosphate concentrations (Figure 5, 6). This positive development in nutrient reduction, in particular in phosphorus can be attributed to improved waste water treatment, which led to a 50 % reduction of phosphorus loading in most North Sea countries in the period 1985-2005 (OSPAR 2008).

Celtic Seas, Bay of Biscay and the Iberian coast

In 2010, measurements of oxidized nitrogen concentrations in the Celtic Seas were only available from Irish and British coastal waters (Figure 1). High concentrations of orthophosphate (> 0.92 µmol/l) were observed in coastal waters in Ireland (Figure 2). In the Bay of Biscay and Iberian Coast, data for oxidized nitrogen concentrations were limited to some stations along the northern coast of Spain (Figures 1), therefore not significant to make an assessment for this sub-region. As for orthophosphate concentrations (Figure 2), most stations where data was available showed moderate to high concentrations.

In the Celtic Seas, the time series of oxidised nitrogen and orthophosphate concentrations showed no remarkable trends, but in general the time series were relatively short (< 10 years). However five stations in the Irish coastal waters (8%) showed a significantly increasing trend in orthophosphate concentration (Figure 4, 6). For the Bay of Biscay and the Iberian coast, not enough time series data were available for this sub-region to calculate trends.

Mediterranean Sea

As limited data are available, the assessments for the subregional Mediterranean seas are combinnedData for 2010 consisted only of Croatian and French coastal observations and from one  location in Cyprus for orthophosphate (Figures 1 & 2). High orthophosphate concentrations (>0.14 μmol/l) are observed at stations near the coast in the Gulf of Lyon and the Gulf of Ajaccio. High oxidised nitrogen (>4.3 μmol/l)  concentrations are observed at near-coastal stations in Croatian waters.

Based on the current dataset, only a few notable changes in nutrient concentrations were detected. In four of the Croatian monitoring stations, an increasing trend in oxidised nitrogen concentrations was found. Generally orthophosphate concentrations did not show clear trends, except for a decreasing trend in one Croatian station (Figures 3 & 4). 

It should be noted that in spite of the oligotrophic nature of the Mediterranean, meaning it is generally characterized by low concentrations of nutrients and low primary productivity, excessive nutrients are anyhow considered a major pollution problem in many of its developed coastal areas (UNEP/MAP 2007, UNEP/MAP, 2012). According to the recent initial integrated assessment by UNEP/MAP (2012), nutrient over-enrichment, possibly leading to eutrophication and hypoxia, are among the pressures and impacts that are common to all four subregions in the Mediterranean (Western Mediterranean, Central Mediterranean and Ionian, Adriatic Sea, Eastern Mediterranean).

Black Sea

The lack of data for this region does not allow showing annual concentrations or calculating trends. 

References

Data sources

More information about this indicator

See this indicator specification for more details.

Contacts and ownership

EEA Contact Info

Constança De Carvalho Belchior

Ownership

EEA Management Plan

2012 1.5.2 (note: EEA internal system)

Dates

Frequency of updates

Updates are scheduled every 1 year in July-September (Q3)
Document Actions
European Environment Agency (EEA)
Kongens Nytorv 6
1050 Copenhagen K
Denmark
Phone: +45 3336 7100