Why should we care about this issue
The biological diversity of Swedish lakes and rivers is low compared to southern Europe. Our knowledge of how many limnic species have disappeared is inadequate. More knowledge of the composition of species in freshwater ecosystems is needed to detect and
a) Why should we care about this theme?
There is a large number of lakes and rivers in Sweden, and due to the low population density, the majority of these are not influenced by point sources of pollution.
Diffuse sources are addressed
The importance of diffuse sources has long been known. The Water Framework Directive demands that the status of all water bodies is established and reported. This has accelerated appreciation of the importance of diffuse sources for release of nutrients, toxic substances and other contaminants harmful to the environment. It has also increased the use of models in determining ecological status, resulting in several projects using monitoring data, land use, discharge, etc.
The biological diversity of Swedish lakes and rivers is low compared to southern Europe. Our knowledge of how many limnic species have disappeared is inadequate. We are in the process of documenting the occurrence of species and are studying threats posed by the introduction of alien species and impacts on habitats. More knowledge of the composition of species in freshwater ecosystems is also needed to detect and follow the expected effects of the climate changes.
The state and impacts
For the most part, Sweden’s water bodies are not rich in nutrients, except in agricultural and metropolitan areas. Acid fallout has decreased by more than 90 % during the past ten years. There are still no clearly established explanations for the high con
b) What are the state (S) and impacts (I) related to this theme, including impacts on the natural environment and human health/human well-being, both at national level as well as in transboundary terms?
For the most part, Sweden's water bodies are not rich in nutrients, except in agricultural and metropolitan areas. This points to the areas in Sweden where we can find bodies of water with excessive nutrients. At the same time as we are seeing a positive trend in water quality, eutrophication of new bodies of water is occurring. One explanation is that while agricultural acreage is decreasing, loading from other sources, such as runoff and traffic, is increasing. In addition, nitrogen and sulphur continue to be introduced from distant sources within and outside the country.
Acidification varies between areas
Acidification is caused by national and international anthropogenic loads. Acid fallout has decreased by more than 90 % during the past ten years. One source of acidifying pollutants that is becoming increasingly important is shipping. Differences within Sweden are large. This is clearly shown in the figure.
How various toxic substances are distributed among water, sediment and organisms depends on the substances' characteristics, such as whether they bind with humus and whether or not they are fat-soluble. Many substances have not been produced, used or spread within the country but have been conveyed through atmospheric fallout. These substances often occur in a gradient from south to north and can be found in otherwise unpolluted water bodies.
Other substances have a particular area of usage or are produced as by-products within industries and occur in more limited places, such as large cities, mining areas, agricultural areas or other specific areas. If these substances are detected in high concentrations, it is often possible to find a way to deal with the pollution since the source can usually be found, the exception being those groups of substances that accumulate in the food chain.
Mercury occurs naturally in high concentrations in Sweden. However, there are still no clearly established explanations for the high concentrations that exist today in almost all Swedish freshwater bodies. There are hundreds of small, seemingly unpolluted forest lakes where the mercury concentration in fish is too high for human consumption of the fish.
The large hydroelectrical constructions and dams in northern Sweden cause enormous impact on the environment. The hydromorphology of many smaller rivers and lakes has also been changed due to hydropower, timber floating, trenching, etc. These changes are often quite old and can be difficult to evaluate. They are also expensive to remediate.
The key drivers and pressures
Agriculture and forestry have their greatest impact on lakes and watercourses through increased concentrations of eutrophication substances and organic carbon (humus material).
c) What are the related key drivers (D) and pressures (P) at national level?
Agriculture and forestry have their greatest impact on lakes and watercourses through increased concentrations of eutrophication substances and organic carbon (humus material). In population centres and along major highways, sewage treatment plants, large industries and car traffic are the main sources of pollution.
Read more in the report Wastewater treatment in Sweden, http://www.naturvardsverket.se/sv/Nedre-meny/Webbokhandeln/ISBN/8400/978-91-620-8416-5/.
See web page with tables on nitrogen and phosphorus loads to inland water and seas,
Groundwater is abundant
Groundwater is comparatively clean and abundant in Sweden. In large areas of Sweden, groundwater monitoring has been poorly developed since there have never been any problems with groundwater quality or levels. But in certain coastal areas there are strong pressures from recreational housing, which can lead to problems with saltwater intrusion in drinking water supplies. The importance of groundwater monitoring is now being established as a fact by the county administrative boards and is a field that is rapidly increasing.
See web page on water withdrawal and water use in Sweden 2005 and 2000, http://www.scb.se/Pages/Product____13063.aspx.
Hydropower has always been an important source of energy in Sweden. There is a large number of old and often unused dams in small and medium-sized rivers all over the country. These constructions change the hydromorphology of the rivers and prevent fish from moving upstream, while at the same time being cherished as places of beauty and historical importance. A challenge for water management is to negotiate between these seemingly contradictory views: the cultural and the ecological values.
The 2020 outlook
Water management continues to lead to increased comprehension of cause and effects when it comes to impacts on natural water bodies.
d) What is the 2020 outlook (date flexible) for the topic in question and how will this affect possible impacts on the natural environment and human health/well-being?
In keeping with the Water Framework Directive, water management continues to lead to increased comprehension of cause and effects when it comes to impacts on natural water bodies. Since the typology and classification of the water bodies according to the WFD have been validated, a better determination of ecological status has become possible, and with it a better understanding of the quality of surface and groundwater.
Runoff of toxins reduced
Stricter requirements for operations such as agriculture, forestry and industry have reduced the runoff of toxins harmful to the environment and substances that cause eutrophication, which also results in cleaner water along the coasts.
We hope that agreements within the EU will result in reduced atmospheric transport and fallout of acidifying substances and heavy metals.
As time goes by, climate changes will lead to increased precipitation in certain areas in Sweden, while others will experience a drier climate. By 2020 we could begin to see repercussions, such as increased water flows after heavy rains, which in turn can lead to flooding in areas near Lakes Vänern and Mälaren (two of the largest lakes in Sweden).
Existing and planned responses
Sweden has action programmes for acidification, eutrophication and many inorganic and organic pollutants hazardous to the environment.
e) Which responses (R) have been put in place or are planned at national level for the theme in question?
Sweden has a very long tradition of monitoring water quality, both chemically and biologically. There is a well-developed system of environmental quality criteria. This system was the model for the quality criteria that have now been incorporated in the Water Framework Directive.
Within the monitoring system, programmes are under way to detect the establishment of alien species as well as to note impacts on surface water caused by climate change at an early stage. As has already been mentioned, we are also developing groundwater monitoring, of both quantity and quality. Among other things, the possible impact of urban areas on groundwater aquifers is being looked into.
Acidification, eutrophication, pollutants
Sweden has action programmes for acidification, eutrophication and many inorganic and organic pollutants hazardous to the environment. The occurrence of anthropogenic organic pollutants is studied through screening at reference sites. Substances we do not find there that exist in other places can be regarded as local/regional pollutants. Others that are more evenly distributed have probably been transported by air from distant places. In Sweden we try to reduce loads as close to the source as possible. With regard to long-range transport of pollutants, we cannot solve the load problem nationally.
However, there are a number of toxic substances that we do not monitor, especially organic pollutants. We need to develop methods of analysis and perhaps enact more stringent legislation to come to grips with those pollutants.
Water management a common interest
In accordance with the WDF, water management has from the start involved county administration, water district administration and national environmental administration. We are also working on increasing cooperation with the government agencies for agriculture and forestry in the water management work. These are the most important areas of land use in Sweden and also important diffuse sources of e.g. phosphorus and nitrogen to surface waters. Working towards better water quality must be a joint effort between all actors and stakeholders.
Information and education on water-related issues are important parts of the agenda for the Swedish Water Authorities. Through consultations with interested parties, the understanding of modern water management will increase. There are also information campaigns about the importance of taking care of our common heritage, such as the brochure The road to better water.
For references, please go to www.eea.europa.eu/soer or scan the QR code.
PDF generated on 29 Jan 2015, 09:54 PM