Running Water : Hydropower Development on Small Waterways

Swedish Society for Nature Conservation Running Water

Hydropower development on small waterways – small benefits but large-scale damage Hydropower has devastated the majority of Sweden’s large In southern Sweden, there are few, rivers. The continued exploitation is now aimed at small if any, waterways that have not been waterways. In order to facilitate the construction of mini regulated for hydropower or not been power stations, the Swedish parliament has allocated sub- affected by other types of physical sidies to small-scale hydropower1. This decision will lead actions. A small number of waterways to the impoverishment of the original ecosystems in run- are protected against further exploi- ning water. The Swedish Society for Nature Conservation tation. It is really only in the far north, believes that the continued destruction of Swedish water- in northernmost Lapland, where the ways cannot be accepted. There is even within the EU the waterways are essentially unaffected by development. But even here, in intention to encourage small-scale hydropower. areas affected by forestry activities, 1When a power station is built on a smaller waterway, it is usually referred to as a mini power station or small-scale hydropower. the construction of roads and ditches

Ljung River mini power station under construction on the Ljung River, Bräcke municipality in central Sweden. Capacity 1,200 kW, dimensioned water discharge 9 m3/s. The concrete dam that will force the water to flow through the turbine of the power station can be seen in the background.

The river is hidden behind the cover in the centre of the picture. At the very right the river is visible but covered with ice. Photo: Hans Isgren has lead to the radical disturbance of hours (TWh) within five years. This is energy resources, there is also the many smaller waterways. the equivalent of less than 0.4 per intention within the EU to encourage On a European level there recent of today’s average hydropower small-scale hydropower. One pro- mains a very small number of large production during a year, and less posal suggests that small-scale hydro- river systems in their original con- than 0.2 per cent of Sweden’s total power should increase by 50 per dition. One of these is shared by electricity production. However, even cent during the period 1995–2010. Sweden and Finland. It is not only more of the irreplaceable living envi- a matter of national concern to pre- ronments of the plant and animals Red-listed and other serve the last remaining free running that inhabit running waters will be sensitive species rivers, but also of international con- destroyed for ever. The single factor that has shown itself cern. As most of the large waterways In contrast to what many people to threaten most red-listed species in have been exploited for hydropower may imagine, a mini power station is Swedish lakes and waterways is the purposes, it is even more important to neither small nor ”cosy”. It is the word regulation of rivers for hydropower. preserve the many small waterways mini that is misleading. Seen in rela- According to the National Swedish that make a highly important contri- tion to the size of the waterway, it is Environment Protection Board’s book bution to the variation and biological not at all smaller than a ”large” power Biological Diversity in Sweden, diversity in the landscape. station. 177 red-listed freshwater species In the summer of 1997, the Swe- The amount of electricity that is are under threat from the regulation dish parliament decided to provide generated by a mini power station is of hydropower. Thereafter follow state subsidies for ”environment- very small. In Sweden there are about over-fertilization (107 species) and friendly, small-scale hydropower sta- 1,550 hydropower stations. Together increased acidity (80 species). tions”, as they are called in the Gov- these give, in a year with normal pre- But it is not by any means only ernment’s energy proposition. Build- cipitation, 65 TWh. 63.5 TWh come species living in water that are threat- ers of power stations can receive from the 350 largest hydropower sta- ened by the regulation of hydro- subsidies equivalent to 15 per cent tions. The remaining 1,200 hydropower. Even species that are con- of the total required investment. The power stations are mini power sta- nected to running water, but that decision is deeply unfortunate. The tions, and electricity production in exist above the water line, can be extra energy provided by the devel- these only reaches 1.5 TWh per year. also seriously affected. What these opment of small-scale hydropower is Most of the mini power stations are in species have in common is that they marginal. The Government itself cal- the south of Sweden. are dependent on the natural water culates the increase as 0.25 terawatt As part of the drive for renewable level fluctuations that occur in a pre-

Reservoirs and dry rapids Hydropower development requires up in the water system (in Sweden usu- are more or less highly fragmented by extensive interference with the natural ally in mountain areas). Annual regula- dams. In the SMHI (Swedish Meteoro- environment. The original, running tion is carried out because electricity logical Office) dam register there are water plant and animal life is replaced demand is greatest during the winter 5,290 dams registered. The register is by lake species. Dams are built on when there is little water in the rivers. based on an inventory of dams that the waterway to force the water to go The extremely high water volumes during was carried out by county councils at through the power station’s turbines spring floods are reduced and stored the end of the 1980s. instead of along its natural course. for use in the winter months. The varia- Examples of other developments Rapids and waterfalls become dry. tions between different times of the year that have had great effect on Swedish Sometimes the power companies are are therefore less noticeable. But the waterways are clearing for the floating required to release a certain minimum water flow in the rivers is still like a of logs and various forms of digging water flow along the original water ”mirror image”, there being high water and straightening. In farming areas, course. The dams are also used to during the winter and low water in the many small waterways have been led store water from night to day (short- summer. The height of water levels in through culverts. It has been necessary term regulation) and from summer to the annual reservoirs can vary by 35 to use culverts beneath all roads in the winter (annual regulation). Short-term metres. Along the shores, enormous countryside. Most of the innumerable regulation, which is carried out close to sterile areas are formed which are alter- road culverts have been laid in such the power stations, leads to extensive natively flooded or left dry and where a way that they hinder the passage of erosion of the river shores. The annual almost nothing can grow. animals up and down the waterways. A regulation reservoirs are situated high Most of the waterways in Sweden serious but overlooked problem.

2 Running Water European view: only four large, untouched water systems, of which three are in Russia Most of the large waterways in Tärendö River which transfers over half fragmentation by dams, and partly on Canada, USA, Europe and the former of the waters from the Torne River to how much the natural water flow has Soviet Union are to a greater or lesser the Kalix River quite high up in the river been affected by reservoirs, and use extent affected by regulation and dam system. for irrigation. constructions. This is shown by a The lower limit for large river sys- A survey was carried out for survey that was published in 1994 in tems has been put at an average medium-sized river systems (average the Science journal. In Europe there water flow rate of 350 m3/s. This aver- water flow rate greater than 40 m3/s remain only four large river systems age water flow should be achieved but less than 350 m3/s) in Denmark, that run freely from source to outlet. somewhere along the river (normally Finland, Norway and Sweden. These Three of these are in northern Russia the water flow is greatest at the river river systems were shown to be and the fourth is in Sweden and mouth, but in desert areas the flow greatly or moderately affected to an Finland. The Swedish-Finnish river becomes less towards the river mouth). even greater degree than the large system is the Torne and Kalix Rivers. An estimate has been made of how river systems in Canada, USA, Europe The rivers are regarded as one river much each river has been affected. and the former Soviet Union. system, as they are connected by the This was based partly on the level of

Remaining unaffected lar ge Gunnilbo River is by no means un- usual. The increased regulation of this

river systems in Eur ope waterway is typical for what has hap-

pened after the upgrading of many

mini power stations that have taken

l Pechora Torne and place in Sweden during the latest 25 M

Kalix älv Mezen o

u years.

n Onega t The lakes and waterways in the

i water system that includes the Gun-

s nilbo River are by no means any virgin environments. Dams built for mining and iron processing have existed at least since the 1600s. At the beginning of the 1940s a mini power station was also built just over a kilo- metre downstream of the actual Gun- nilbo River. But the possibilities of 0 400 800 1 200 kilometres regulating the water flow with exist- After Dynesius and Nilsson (1994) Illustration: Björn Möllersten ing dams has during recent decades only been partly used, which is why defined yearly cycle in free-flowing River in Västmanland have been docu- its waters have been allowed to flow waterways. The plant and animal mented by a number of coincidences. relatively freely. communities that these species are The result shows the often cata- A change of landowner in 1995 part of are strongly influenced by strophic effects of the introduction marked the beginning of an overall water level variations, such as when of hydropower on the animal life of change in the regulation of the Gun- more common stronger rivals are held small waterways. The local brown nilbo River. The new landowner and back by the high waters of spring trout population – which was prob- the owner of the falls (somebody floods. ably genetically unique – disap- living near Stockholm) commenced peared after increased regulation the regulation of the water flow with Drastic worsening of the in 1996. Nor has the water shrew the aim of maximizing the income Gunnilbo River been seen there since 1995. The from the mini power station. During There are very few reports on animal dipper also disappeared at first but 1996, the variations in water flow and plant life in a waterway before has now returned. were very sudden and large. At cer- and after regulation. Developments The regulation of the water flow tain times the river was full of water, of mainly animal life in the Gunnilbo that has been carried out in the and at other times large areas of its

Running Water 3 Small-scale hydropower in Sweden and the EU Put simply, a mini power station is a disturb fish and small animals during defined in the same way. Sometimes hydropower station that has been built their natural movements, ruined spawn- the term micro power station is used, on a small river or large stream. These ing grounds and dry rapids and water- which refers to power stations with a waterways are very small in relation to falls. The variation in the water flow capacity lower than 0.1 MW. the major rivers. And it is clear that can be both greater and smaller than The definition used in discussions a power station built on a stream or in the major regulated waterways. The concerning small-scale hydropower small river needs to be a very small original plant and animal life can be within the EU is considerably more one. But a mini power station is in wiped out. generous than the Swedish definition. principle a smaller copy of the power Mini power stations are defined in In EU contexts, hydropower stations stations that have caused such havoc Sweden as power stations with a maxi- with a capacity up to 10 MW are con- on major rivers. The damage caused is mum capacity of 1.5 megawatts (MW). sidered to be mini power stations. also of the same type, e.g. dams that The term small-scale hydropower is

Facts about the bottom-living fauna species that are shown in the diagram

The mayfly Baetis rhodani is the It requires fast-flowing oxygen-rich most common mayfly in running water water. Hydropsyche cannot swim in Sweden. It is a fast-swimming spe- and are therefore marooned on dry Hydropsyche cies that lives mainly in stony, fast- shores if water levels go down rapidly. flowing areas. It lives chiefly on algae. They then die in large quantities. They bed were laid dry. The width of the It is seldom longer than 1 cm. The are sensitive to clouding of the water. waterway varied between about 7 Baetis genus is the most important If there is extreme cloudiness, their metres and 1–2 metres. The differ- food for growing brown trout and is webs can become blocked and the ence between the highest and lowest also commonly found in the stomachs animals are stressed to death in their flow was much greater than it would of other fish that live in strong cur- attempts to keep their webs clear. have been under more natural cir- rents. As a winged insect, Baetis is They belong nevertheless to the most cumstances. an important source of food for many tolerant of species among the bottom- The rich bottom-living fauna (ani- types of small birds. It tolerates vari- living fauna. The figure shows the fol- mal life on and in the river-bed) of ous types of environmental changes lowing species: H. siltalai, H. pellu- the Gunnilbo River deteriorated enor- better than other mayflies. It is how- cidula and H. angustipennis. mously. Of the 198 taxa (biological ever very sensitive to changes in Freshwater louse (Asellus aquat- categories) that were found before oxygen levels and reductions in water icus) is found in all types of fresh- flow speed. In contrast to other may- water in the whole country except 1996, 62 were missing from tests flies,Baetis is not capable of moving mountain areas (also in the Baltic carried out in 1996 and 1997. Many its gills to pump oxygen-rich water Sea). In running water it is usually of the animal groups that have dis- which is why it must be surrounded found in areas where the flow rate is appeared are characteristic of fast- by oxygen-rich water with a strong slow. It moves with a slow crawl and flowing water. The character of the current. eats detritus and dead animals. Asel- bottom-living fauna of the Gunnilbo The caddis fly genus Hydropsy- lus aquaticus is much favoured by River has changed and today con- che are to be found in all types of human interference. It tolerates very sists of typical inland lake species, running water over the whole country low levels of oxygen, very high metal- which come from upstream lakes. except in mountain areas. They grow lic levels, very high nutritive salt levels The disappearance of the dipper to a length of between 10 and 15 mm and very clouded water conditions. and the water shrew is explained and are the favourite food of the It can also survive on dry land for largely by the extensive reduction in dipper. They build themselves a pro- much longer than most other aquatic the quality of the bottom-living fauna tective cover for instance between small animals. The freshwater louse during 1996. Important food organ- stones, which are by no means the forms an important source of food for same as the house-building of the fish, as well as for predating larvae isms amongst caddis flies and may- caddis flies. TheHydropsyche genus of stoneflies, caddis flies and dragonflies retreated sharply or disappeared. spins a web which is about 1 cm2. flies. The dipper is a dedicated bottom-liv- It feeds on the animals and pieces The taxa (biological categories) ing fauna specialist which prefers to of plants that are caught in the web. that are shown in the figure form a eat caddis fly larvae. Stream-resident

4 Running Water Regulation effects on bottom-living fauna, dipper and trout

Number of individuals of Baetis Number of individuals of rhodani and Hydropsyche per Asellus aquaticus per year at standardized test year at standardized test

3 500 12 000

3 000 10 000

2 500

8 000

2 000

6 000 1 500

4 000 1 000

2 000 500

0 0 1992 1993-95 1996 1997

Hydropsyche Dipper1 Small changes of water level

Baetis rhodani Trout1 Moderate changes of water level

1The symbols do not repre- sent any measured values but Asellus aquaticus only state whether the spe- Large changes cies occurs or does not occur. of water level

good cross-section of animals living Test method: M42 in running water. Their reaction to the altered flow conditions in the The bottom-living fauna tests in the that has been collected in a net (diam- Gunnilbo River are typical for how Gunnilbo River have been carried out eter 16 cm and mesh width 1 mm) the fauna react in equivalent situa- using a method known as M42. It after the bottom within an area of about tions in the whole country except is described in the National Swedish 0.2 m2 has been disturbed by kicking it mountain areas. They have been Environment Protection Board’s hand- for a period of 5 seconds. chosen because they are typical, not book for environmental monitoring. because they differ in any way. Briefly, M42 means that 30 samples The taking of test samples and identification of species has been carried out by Eva Eng- are taken from a 50 m stretch of river blom. Pär-Erik Lingdell was responsible for Facts: Pär-Erik Lingdell and Eva Engblom shore. Each sample contains material the analysis of the data.

Running Water 5 Classification of the bottom-living fauna and its use as an environmental indicator Important animal groups amongst the live mostly on leaves that have fallen into Most small animals that live in bottom-living fauna are snails, mussels, the water. Scrapers (e.g. many mayflies water are sensitive to environmental leeches, worms, crustaceans and and snails) eat microscopic growth on changes. They are therefore ideal envi- insects. Among insects it is above all stones and plants. Filterers (e.g. mus- ronmental indicators. When periodic the larvae stages of some groups that sels, blackfly larvae and many caddis chemical samples are taken, momen- live on and in the bottom. Examples flies) filter the free floating bacteria and tary drops in e.g. oxygen levels or pH of such groups are stoneflies, mayflies fine organic material from the water. values can easily be missed. But such and caddis flies. Among beetles there Among the caddis flies there are many brief environmental changes are often are several species that live in water species that spin a special web for easily revealed by an examination of the even when fully developed. catching food. Detritus eaters (e.g. bottom-living fauna. There is a strong The bottom-living fauna is usually midge larvae and many earthworms) indication that something of a serious divided into so-called functional groups eat partly decomposed organic material. nature has occurred if species that do according to how they obtain their food. Predators are found in many groups, not tolerate low oxygen levels or pH Shredders (common among stoneflies) e.g. beetles, dragonflies and leeches. values have disappeared. brown trout (Salmo trutta fario), the bottom-living fauna has recovered There are several interacting rea- types of brown trout that live station- most of what has been lost in terms sons behind the drastic changes that ary in smaller waterways, feed to a of species and number of creatures – have taken place amongst bottom- large degree on bottom-living fauna. provided no new disturbances occur. living fauna. Water level variations The water shrew eats small aquatic But it would seem that the trout stock are the most important factor. Large animals. has been killed-off for good. quantities of dead small animals have The final death blow for trouts was The large increase in numbers of been found on the exposed shores the occasional very low water levels freshwater lice which is shown in after rapid reductions in the water to which regulation led. During Janu- the accompanying figure is probably level. Another factor is periods during ary and February 1996 the slightly due to the reduced predation by fish which the water has quickly become raised shingle banks where the trout and preying insects. This water louse clouded. The latter is caused mainly had laid their spawn during the previ- belongs to the small group of organ- by rapid rises and falls in water ous autumn became dry. The spawn isms that thrive on increased acidity, levels. Increased cloudiness, and the froze or perished due to the dry con- pollution and other disruptions in the increased deposition of fine silt that ditions. water environment. The freshwater the cloudiness leads to, disrupts the Protests from local residents, as louse has increasingly taken over foraging and reproduction of many well as negative publicity in the local and is today (winter 2001–2002) the small animals. The cloudiness is also press, led to a more careful control of dominating species. The two insects connected with the fact that the con- the water from the middle of 1996. shown in the figure, the mayfly Baetis tent of particle humus (incompletely Brief but large falls in water levels rhodani and the caddis fly genus broken down organic material) has have, however, occurred even after Hydropsyche, are important food increased markedly since the land- the middle of 1996. Brief periods of organisms for trouts and dippers, owner change in 1995. The more clouded water have also been noted. respectively. Both are relatively tol- intensive regulation causes the water A certain degree of recovery has erant and recolonize quickly after at intervals to encroach higher up taken place amongst the relatively drastic falls in population levels. The on land than before, and therefore tolerant species of the bottom-living increase in numbers in 1997 was increases the leaching of humus.1 In fauna. Experience has shown, how- helped by the fact that both the trout addition the depleted oxygen levels of ever, that it can take 20 years before and dipper were absent. the water, which is an indirect result of low water levels, has had a bad effect on the bottom-living fauna. Increased cloudiness and humus content also cause problems for trout.

1To give a fair picture, it should be mentioned that the situation has been made worse by the opening of an area of peat in the upper reaches of the catchment area Asellus aquaticus during the 1990s and from which humus is carried out.

6 Running Water The river-beds can be so blocked by Small animals are tricked into silt and humus particles that the trout flying wrong or are killed in cannot dig its spawning ground. This the power station has occurred in the Gunnilbo River. It is easy to understand that a mini- The survival of the spawn can also mum release equivalent to only be disturbed because the fine silt 5–10 per cent of the average water and humus particles that are laid stop flow would have serious conse- fresh, oxygen-rich water from passing quences for plants and animals in through the shingle beds where the the waterway. Not least the bottom- spawn is laid. Baetis rhodani living fauna, which forms an important food source for e.g. many types ”Environmentally friendly” of fish, is greatly affected. In the dry hydropower stations? part of the Ljung River the bottom- Exploitation interest groups like to living fauna that are dependent on speak of ”environmentally friendly” owner. Making a hydropower station running water will more or less dis- power stations. What is meant in gen- environmentally friendly in a meaning- appear. eral, where small-scale hydropower is ful way is therefore difficult or impos- When individual winged species concerned, is that the power station sible. of the bottom-living fauna are on their is run without the need for a reservoir It is important to remember that way up the waterway, they fly. They for short-term or annual regulation. achieving environmental friendliness need to make their way upstreams as This reduces damage to the environ- can never, except in minor ways, com- the larvae are carried downstream in ment, but what cannot be avoided pensate for the enormous environ- the water system during their devel- is that the water must be passed mental damage that the regulation of opment period. If the animals find through the turbines of the power hydropower causes. themselves in far too small water station. This means that the water- Two examples of planned mini flows they can become disorientated way has a dry section by the power power stations without a reservoir and fly wrong. The females then lay station, usually a stretch of rapids or are Fallfors power station on the Mo their eggs in places that are less waterfall. River on the coast of Norrbotten and suitable for the purpose, with the Modern water legislation often the Ljung River power station in east- result that many of the eggs perish. requires a minimum release of water. ern Jämtland. Fallfors power station Unnaturally low flows as a conse- A certain amount of water is required would leave dry a 1.5 km stretch of quence of power station construc- to be allowed to go past the power rapids for 10 months of the year (July– tion therefore make the natural re- station along the natural river-bed. As April). The bottom-living fauna in the colonisation impossible or seriously a rule the minimum release is 5–10 Ljung River has been shown to con- restrict it. per cent of the average water flow sist of an exceptionally large number Many larvae (but also fully devel- of the waterway, in some cases even of different species. The Ljung River oped individuals that have landed on less. Sometimes the minimum release power station will leave a 500 metre the surface of the water) are carried requirement does not apply to every stretch of rapids dry for nine and a down the waterway. If we assume month of the year. In order for the half months of the year (middle of that 90 per cent of the water flow minimum release to have any effect July to April). A small compensation runs through the power station, it on fish, it should be between 10 and is that a water volume equivalent to follows that 90 per cent of the float- 30 per cent of the average water about 7 per cent of the average water ing small animals also go through flow. If there are salmonids in the flow will be released into a specially the power station. And most of them waterway, then at least 30 per cent of created fish route from 1st April to are killed or injured when they pass the average water flow should apply. 31st October. through the turbines of the power In addition, attempts should always The Mo River was very recently station. Many of the small animals be made to copy the natural sea- saved, not because any court found that live in water are very fragile. sonal variations of the water flow. At the planned power station incompat- During testing of the bottom-living the same time such minimum release ible with the Swedish Environment fauna it has proved difficult to gather requirements mean that the power Act, but simply because the county in the animals in such a way as to station could create a loss for its administration decided to buy out not injure them. owner. Every cubic metre of water the developer. In the Ljung River, the Where fish are concerned, many that is led past the power station power station is being built right now are hacked to pieces in the tur- represents an economic loss for the (see picture on page 1). bines.

Running Water 7 Untouched tributaries are way. Most of them make their way About 70 per cent of the economi- important havens of retreat instead into the smaller tributaries cally viable hydropower in Sweden In river valleys where there are several where the sea trouts can find the has already been developed. In many power stations and where the slow conditions they require for spawn- areas, especially Värmland, Jämtland flowing stretches have been dammed ing. The same applies to spawning and southern Lapland, the developed to form reservoirs for the power lake dwelling brown trout, who mostly level is over 90 per cent. Only in stations, the smaller tributaries are leave their home lake to enter the two major rivers – the Torne and often the only remaining natural flow- smaller tributaries. The salmon, how- Kalix Rivers in the far north – is the ing environments. A large number of ever, spawns chiefly in the large water permitted to run freely from its brown trout stocks (several hundred) unregulated waterways. sources in the mountains to the sea. have been eliminated or substantially More hydropower will not solve reduced in the regulated rivers. In the Sixth place in the hydropower Sweden’s energy problems. But a counties of Västerbotten and Jämt- league table single mini power station can destroy land almost half of the known stocks Only in Norway, Iceland, Canada, Para- parts of the biological diversity that of full-grown brown trout are gone. guay and New Zealand is there more Sweden has promised on an interna- The tributaries that flow into the regu- developed hydropower per capita tional level to conserve. lated rivers have an especially impor- than in Sweden. The figures in the tant function, as they still have spawn- table apply to 1996 and are from the ing grounds intact and are good envi- Statistical Yearbook for 2001. ronments for fish such as young trout to grow up in. The fish can then grow Country Production of hydro- Population Hydropower electricity power electricity (TWh) (millions) (kWh) per capita big out in the power station reservoirs (assuming that there is no large Norway 104.0 4.4 23,636 presence of pike which is a very effi- Iceland 4.8 0.3 16,000 Canada 352.6 30.0 11,753 cient predator). Paraguay 48.0 5.0 9,600 The still free-flowing rivers’ small New Zealand 25.7 3.6 7,139 Sweden 51.5 a 8.8 5,852 tributaries (or tributaries of the tribu- Austria 35.6 8.1 4,395 taries) are also important reproduc- Switzerland 29.7 7.1 4,183 Venezuela 56.0 22.3 2,511 tion areas for brown trout. When the Finland 11.9 5.1 2,333 sea trouts make their way in from the a sea to spawn, they do not by any In 1996 hydropower production was much lower than normal in Sweden. The average figure is about 65 TWh per year. During a normal year the figure is about 7,400 kWhhydro power electricity per capita. means all remain in the main water-

Sources and bibliography The most important facts for this information sheet Mats Dynesius and Christer Nilsson. Science 4th Hydropower development on small waterways – have been provided by Pär-Erik Lingdell and Eva November 1994. small benefits but large-scale damage Engblom, Limnodata HB. Judicial papers concern- Älvboken. Maria Gardfjell, Gudrun Nordstedt ing the conjectured mini power stations have also and Maria Wikman (ed.). Fältbiologerna, 1985. Text: Björn Möllersten been used. Here are some of the reports and Älvbokssupplement. Björn Johansson. Fältbio- Translation into English: John Hooker books that this information sheet has been based logerna and Naturskyddsföreningen, 1997. Drawings: Eva Engblom on in part, or which are of general interest concern- Liming Restores the Benthic Invertebrate Map: Björn Möllersten ing the subject. Community to ”Pristine” State. Acid Reign ’95?, Layout: Mats Brant volume 2. Pär-Erik Lingdell and Eva Engblom. Printed by: Tryckarna Ahlgren & Söderman AB Biologisk mångfald i Sverige. En landstudie. Kluwer Academic Publishers, 1995. Paper: Munken Cream 115 g. Claes Bernes (ed.). Naturvårdsverket,1994. (Avail- Fisk och turbiner. Erik Montén. Vattenfall, 1985. Order No: 9192 able in English: Biological Diversity in Sweden. Miljöförbättringar i utbyggda vattendrag – A Country Study.) internationella utblickar. Temafakta. Naturvårds- Swedish Society for Nature Conservation Sveriges Nationalatlas. Miljön. Claes Bernes verket, 1997. Åsögatan 115 and Claes Grundsten (theme editors). Kartförlaget, Skyddade älvar. Värden att bevara. Christer P.O. Box 4625 Gävle, 1991. (Available in English: The National Nilsson and Marie Tobiaeson (ed.). Naturvårdsver- SE-116 91 Stockholm Atlas of Sweden. The Environment.) ket, 1996. Strandskalbaggar, biologisk mångfald och Subventioners inverkan på en ekologiskt Phone: +46 8 702 65 00 reglering av små vattendrag – exemplen hållbar utveckling. Tre fallstudier. Riksrevisionsver- Fax: +46 8 702 08 55 Svartån och Mjällån. Sven-Åke Berglind, Bengt ket. RRV 1998:6. E-mail: [email protected] Ehnström and Håkan Ljungberg. Svensk Entomo- Svenskt dammregister, södra Sverige. SMHI, Website: www.snf.se logisk Tidskrift 4/97. 1994. Ekologisk fiskevård. Erik Degerman et al. Svenskt dammregister, norra Sverige. SMHI, Sportfiskeförbundet,1998. 1995. Fragmentation and Flow Regulation of River Vetande om vatten (theme issue). Skog & Systems in the Northern Third of the World. Forskning 4/95. Sveriges Skogsvårdsförbund. © Swedish Society for Nature Conservation 2002