Freshwater - State and impacts (Iceland)

With few exemptions, the coast is the main recipient for wastewater discharges, but this is not problematic.

Ecological quality

Iceland is a volcanic island predominantly formed of basaltic rock of the Quaternary and Tertiary Ages. The classification of Icelandic running waters and their ecosystem has mainly been based on bedrock type and topography (1, 2). Rivers running from well-vegetated moors and rivers with lake influences within the catchments seem to have higher biological productivity and diversity than rivers draining barren areas (3). In spite of diverse freshwater types, the number of species is low. Seven species of freshwater fish are present, 146 species of rotifers, around 120 species of insects, 89 species crustacean, 26 species annelids and 10 species hydracarina. Two species of chironomids (4) and two species of subterranean freshwater amphipods are endemic. The low number of species can be explained by Iceland’s climate and isolation from continental Europe (5).

Three wetland areas are Ramsar sites, Mývatn-Laxá, Þjórsárver and Grunnafjörður, and three others are under consideration.

The Icelandic Institute of Natural History advises on sustainable use of natural resources and land development, and assesses the conservation status of species, habitats and ecosystems.

The Institute of Freshwater Fisheries conducts research on freshwater fish and publishes annual reports with freshwater fisheries statistics and fish stocks management evaluation.

In the EU´s water framework directive, Iceland´s fresh waters are classified as unique eco-region.

Nutrients in rivers and streams

Monitoring of river chemistry started on a regular basis in 1998. First stations were located in rivers in South and East Iceland. A fair survey of the nitrate concentration in the country's principal rivers exists (6, 7, 8). Riverine transport has been estimated (Table 1. (7)). Based on Table 1, the total N runoff is estimated as 4360 tons.

Table 1. Estimated riverine transport from Iceland (7)

The ranges for nitrate nitrogen (NO3-N) are:

•           South Iceland, between <0.002 and 0.055 mg NO3-N/l;
•           in East Iceland, between <0.002 and 0.124 mg NO3-N/l.

The ranges for phosphate (PO4-P) are:

•           in South Iceland, between 0.00 and 0.055 mg (PO4-P)/l,
•           in East Iceland, between 0.002 and 0.081 mg (PO4-P)/l.

In Figure 1, the results of total phosphorous (Tot-P) and total nitrogen (Tot-N) for 20 rivers in Iceland are shown. The rivers were sampled regularly over one or two-year periods (9) and most of the rivers have no significant human pressure. Rivers within urban settlements reveal some elevated values.

Figure 1. Mean and 90 percentile values (10 to 14 samplings) of Tot-P and Tot-N in 20 rivers in Iceland (9).

Eutrophication in lakes

The nutrient status of 59 lakes was measured in the period 1997-2000 (ESIL database, 17). Forty-nine have nitrate nitrogen concentrations (NO3-N) of less than 0.005 mg/l and all the lakes have concentrations less than 0.05 mg/l. For total Tot-N, 52 lakes have less than 0.3 mg/l-N, 5 0.3-0.75 mg/l-N and 2 0.75-1.5 mg/l-N. For Tot-P, 48 lakes have less than 0.025 mg/l-P and 11 0.025-0.125 mg/l-P. Many Icelandic lakes may thus have rather high natural concentrations of Tot-P possibly because of high weathering rates of volcanic bedrock.

Airborne deposition

Long-range air pollutants originate largely from emissions from industry, transport and agriculture in Western and Central Europe. The nearest distances from Iceland to the European continent are 970 km to Norway and 798 km to Scotland. The country is thus far from the industrialised and heavily populated regions in Europe and is only mildly subjected to anthropogenic long-range sulphur (S) and N-deposition.

Critical loads for S acidity in 48 Icelandic lakes have been calculated based on the steady-state water chemistry (SSWC) of Henriksen and Posch, (10).

Table 2. Percentiles for critical loads and S acidity deposition (meq m^-2 yr^-1) for 48 lakes in Iceland.

Because of the high threshold of critical loads and the low S (acid) deposition, critical loads are not exceeded in any of the lakes (11).  

Modelled total annual nitrogen deposition in the Administrator of the Oslo and Paris Conventions (OSPAR) regions in 2004, shows as less than 200 mg/N m² in Iceland (12). The national contribution to oxidised nitrogen is estimated as 8 % and 27 % to reduced nitrogen (13).

Volcanic emissions are important for the chemical composition, in particular in periods during eruptions. The initial explosive phase of the 1991 eruption of the Hekla volcano caused acid snow to fall over much of north and east Iceland, and snow close to the vent was found to be enriched in fluorine, chlorine, silicon, aluminium, iron, manganese, titanium and phosphorous. There were some, but not striking enrichments, in sulphur. Increased concentrations of some chemical constituents were found in a river near the volcano during snowmelt (14).

Groundwater quality

Available analyses of drinking water quality – spring water, well water and surface water –show that the nitrate expressed as nitrogen concentration in water used for drinking is under 3 mg/l-N, or less than 13 mg/l nitrate (NO3), well below 25 mg/l- NO3 guideline (15).

Figure 2. Nitrate in drinking water in Iceland (15)

References

(1) Jonsson, G.S., I.R. Jonsson, M. Björnsson & S.M. Einarsson. 2000. Using regionalization in mapping the distribution of the diatom species Didymosphenia geminata (Lyngb.) M. Smith in Icelandic rivers,  Verh. Internat. Verein. Limnol. 27: 340-343.

(2) Jón S. Ólafsson, Gísli Már Gíslason and Hákon Aðalsteinsson. 2002. Icelandic Running waters: anthropological impact and their ecological status. In: Marja Ruoppa and Krister Karttunen (eds.). Typology and ecological classification of lakes and rivers. TemaNord 2002:566. Nordic Council of Ministers, Copenhagen 2002.

(3) Gislason, G.M., H. Adalsteinsson & J. S. Ólafsson. 1998. Animal Communities in Icelandic Rivers in Relation to Catchment Characteristics and Water Chemistry. Nordic Hydrology -An International Journal 29 (2):26 - 33.

(4) Hrafnsdottir, Th. 2005. Diptera 2 (Chironomidae). The Zoology of Iceland III, 48b: 1-169.

(5) Gísli Már Gíslason, 2005. Origin of freshwater fauna of the North-Atlantic islands; present distribution in relation to climate and possible micration routes. Verh. Internat. Verein. Limnol. 29 (1): 198-203.

(6) Unnsteinn Stefánsson & Jón Ólafsson, 1991.  Nutrients and fertility of Icelandic waters. Rit fiskideildar 12, 1-56

(7) Sólveig R. Ólafsdóttir 2006. Næringarefnaástand í hafinu við Ísland. Hafrannsóknastofnunin, skýrsla. Október 2006 (Nutrient concentrations in Icelandic waters, report in Icelandic).

(8) Sigurður Reynir Gíslason, Árni Snorrason et. al Annual reports. Gagnagrunnur Raunvísindastofnunar og Orkustofnunar. (University of Iceland, Science Institute and Energy Authority Database)

(9) Tryggvi Þórðarson, 2003. River Varma, Hveragerdi. Water quality monitoring 2001 – 2002. Rannsókna- og fræðasetur Háskóla Íslands í Hveragerði.

Tryggvi Þórðarson, 2003. Classification of lakes and rivers in the district of Kjos, River Botnsa. Rannsókna- og fræðasetur Háskóla Íslands í Hveragerði.

Tryggvi Þórðarson, 2003. Classification of lakes and rivers in the district of Kjos, River Brynjudalsa. Rannsókna- og fræðasetur Háskóla Íslands í Hveragerði.

Tryggvi Þórðarson, 2003. Classification of lakes and rivers in the district of Kjos, River Bugda. Rannsókna- og fræðasetur Háskóla Íslands í Hveragerði.

Tryggvi Þórðarson, 2003. Classification of lakes and rivers in the district of Kjos, River Fossa. Rannsókna- og fræðasetur Háskóla Íslands í Hveragerði.

Tryggvi Þórðarson, 2003. Classification of lakes and rivers in the district of Kjos, River Kidafellsa. Rannsókna- og fræðasetur Háskóla Íslands í Hveragerði.

Tryggvi Þórðarson, 2003. Classification of lakes and rivers in the district of Kjos, River Laxa in Kjos. Rannsókna- og fræðasetur Háskóla Íslands í Hveragerði.

Tryggvi Þórðarson, 2003. Classification of lakes and rivers in the district of Kjos, River Leirvogsa in the Town of Mosfellsbær and the City of Reykjavik. Rannsókna- og fræðasetur Háskóla Íslands í Hveragerði.

Tryggvi Þórðarson, 2003. Classification of lakes and rivers in the district of Kjos, River Ulfarsa. Rannsókna- og fræðasetur Háskóla Íslands í Hveragerði.

Tryggvi Þórðarson, 2004. Classification of Human Impact on the Rivers Sudura, Holmsa and Ellidaar. Háskólasetrið í Hveragerði

Tryggvi Þórðarson, 2004. Classification of lakes and rivers in the district of North East Iceland, Rivers Eyjafjardara, Glera, Hoerga and Svarfadardalsa. Háskólasetrið í Hveragerði

Tryggvi Þórðarson, 2005. Classification of lakes and rivers in the district of North East Iceland, Rivers Fnjoska, Skjalfandafljot and Laxa in the district of Þingeyjarsysla. Háskólasetrið í Hveragerði.

Tryggvi Þórðarson, 2005. Classification of lakes and rivers in the district of Kjos, River Varma. Háskólasetrið í Hveragerði.

(10) Henriksen, A. and M. Posch, Steady-state models for calculation critical loads of acidity for surface waters. Water, Air, and Soil Pollution: Focus, 1: 375-398, 2001.

(11) Skjelkvåle, B.L. 2001 et. al. Chemistry of lakes in the Nordic region – Denmark, Finland with Åland, Iceland, Norway with Svalbard and Bear Island, and Sweden. NIVA, Acid Rain Research, Report No. 53/2001, Serial No. SNO 4391-2001, 2001.

(12) OSPAR Commission, 2007: Atmospheric Nitrogen in the OSPAR Convention Area in 1990 – 2004. ISBN 978-1-905859-83-2. Publication Number No. 344/2007

(13) Norwegian Meteorological Institute, 2007. Transboundary air pollution by main pollutants (S, N, O3) and PM. Iceland.  EMEP/MSC-W: Heiko Klein, Anna Benedictow and Hilde Fagerli. ISSN 1890-0003

(14) Sigurður Reynir Gíslason, et. al. 1992. Local effects of volcanoes on the hydrosphere: Example from Hekla, southern Iceland. In: Kharaka and Maest (eds.): Water-rock interaction. Balkema, Rotterdam

(15) Environment Agency of Iceland, 2008. Report concerning Art. 10 of the EU's Nitrate Directive. 2008 report.

(16) Chemical quality of drinking water in Iceland and protection of the water resources. MSc thesis in Icelandic. http://www2.hi.is/Apps/WebObjects/HI.woa/1/swdocument/1006286/MS_UB_MJG_2005.pdf