I have done a follow up study of the restoration of two Rivers, Röälven and Grundan, in order to evaluate the effects of the restoration on the endemic population of trout. Both Rivers have been used for timber floating during many years throughout the 20th century, and because of this, had all obstacles such as rocks and wood parts removed. In 2004-2005 both Rivers were restored, and rocks and wood were put back into the Rivers. Spawning grounds were created and boulder dams were constructed to promote the streaming water. The result showed that the trout population of both Rivers increased after the restoration, but also that the trout population of Röälven increased more than that of Grundan.

Nutrient enrichment is the main cause of the increasing eutrophication process in the Baltic Sea during last century. A prerequisite counteract this process the load of nutrients to the Sea must be investigated. The large contribution of nutrients to the Sea is caused by emission from the Rivers within the drainage basin. For the total emission of nutrient into the Sea the retention process in the Rivers has big influence. This process in the river system has been assumed as a not important part of the nutrient cycle.

The population of seatrout and salmon are threatened by over-fishing in the sea and loss of spawning and growing habitats caused by logging activities in many swedish Rivers. The knowledge of the spawning migration and the habitat use of the seatrouts and salmon are limited. This study analyse the upstream spawning migration of Atlantic salmon and sea-running brown trouts from the lower part of the Rivers to their spawning sites in the Rivers Vindelälven and Piteälven. A knowledge about the distribution of spawning sites in the Rivers will help these fish population in future restoration programs. In the fishladder at Norrfors in the river Umeälven were 29 sea trout and 20 salmon radio tagged and subsequently released and followed during their spawning migration upstream Vindelälven. They were tracked on their position in the river once a week.

Chile and Santiago are struggling with heavy environmental problems as a consequence of urbanisation and industrialisation. In the Santiago region the air is seriously contaminated and most of the Rivers are classified as heavily polluted.The aim of this thesis is to survey the industrial fluid waste situation in the Santiago region and to make suggestions on technological improvements or process changes. The purpose is also to study five different enterprises more closely and to give more detailed suggestions for improvement. Another purpose is to summarize relevant Chilean legislation.Information, provided by the supervisory authority, about the release of industrial wastewater to Rivers has been analysed. Deep interviews have been made with authorities and consultants.

This essay discusses the Laholm?s bay and its eutrofication problems. The question of issue is: Have the efforts to limit the eutrofication in the Laholm?s bay been effective? What is the local actor?s opinion whether the measures have been effective or not? What efforts have been made to prevent the leakage of nutrients from fields and forestland? The Laholm's bay is located in the south part of the Swedish west coast. The problem was noticed in the 1960´s by local fishermen that experienced a lack of catch.

Regulation of Rivers by dams and reservoirs is a good example where anthropogenic impact could be considerable both in the local environment, but also has major implications upstream and downstream. This study was accomplished as a literature study of the river Nile, which is extremely important for water supply. The purpose of this study was to investigate the consequences of the construction of the Aswan High Dam, to obtain a consistent flow for water supply, irrigation and power generation in Egypt. Since Egypt has a very hot and dry climate large amounts of water in reservoir is lost to the Nubian aquifer system and by evaporation. The consequences from constructing the dam are considerable.

Lerbodaälven is a river in the municipality of Kil which, due to high phosphorus content is not meeting the requirements for good ecological status according to the Water Framework Directive. The purpose of this report is to investigate the causes for the high content of phosphorus that has been measured in Lerbodaälven between 1995-2010. Four questions will be answered in this report. 1. Does the sewage treatment work affect the phosphorus level in Lerbodaälven? The result from the time series analysis shows that the sewage treatment works have a small impact on the phosphorus level in Lerbodaälven.

Hemp has been used for textiles for a long time in history until it became illegal to grow in many countries in the 1930s. It is interesting from an environmental point of view because it doesn?t need any pesticides and in most locations it doesn?t need any irrigation either, compared to cotton, which normally requires big amounts of both pesticides and water for irrigation. Hemp is a bast fiber, which means that the fibers are located on the bast of the stem (on the outer layer of the stem). Therefore they cannot be spun directly, they have to be removed from the stem first.

Today?s climate changes will probably give rise to precipitation in Sweden, which will cause more floods in Swedish Rivers. Many of the Swedish Rivers are regulated and have lots of hydro-electro power plants. Higher floods in the Rivers will give greater water loads on the dams, which mean that a higher discharge through the sluice gates and in the spillway channels is needed. High discharge of water in a spillway channel can create scour of the material in the channel.

Guazuigua is a small village in Bolivia, which has had too small water resources, especially for irrigation. A project started after some studies were made, to create a canal to provide the village with water from a nearby town. To make the canal work it had to cross a dried out river. There have been several attempts to cross these dried out Rivers, but with poor results. The purpose of the report is to provide a solution for this problem.

In Sweden you will find the coot chiefly in the southern parts. The species winters in the southern part of the Baltic Sea and along the coasts of northern Europe. The number of coots is heavily decreased by harsh winters. The population of the coots in Sweden is estimated to 20 000 to 30 000 pairs. The region of Dalarna is the random zone for the breeding of coots in Sweden .

The last hundred years humans have drastically changed the amount of available nitrogen in nature. Today human activities release twice as much available nitrogen as all natural processes are doing together. We also have degraded nature´s possibilities to take care of nitrogen through the draining of wetlands and straightening of Rivers. In order to regain the potential of nitrogen retention in the water systems there now requires a reshape of the landscape we live in. A planned expansion of the mining activities in Garpenberg, Dalarna, would double the content of nitrogen in the waters below the mine.

Environmental chemicals are transported to the Arctic through the air and oceans, once within the Arctic they spread through Rivers, lakes and other watercourses. Polar bears and sledge dogs in-gest high concentrations of environmental chemicals since many of the chemicals are fat-soluble and their diet mainly consists of marine mammals. The aim of this study is to describe how environmental chemicals spread in nature, how they reach the polar bears, and finally how they affect the animals reproduction, with reproductive hormones and genitals in focus. The animals are exposed to a cocktail effect which complicates the assessment of the chemicals impact on the reproduction. Studies show that the genitals can decrease in size or become malformed, sexual maturation can be affected and the reproductive hormones can be disturbed.

In many regulated Rivers, authorities have stocked hatchery salmon to compensate for loss of wild populations. However, hatchery fish have not always behaved as wild fish do, and stocking them has not always fully compensated for the loss of wild fish. The purpose of this study was to compare swimming behaviour in the river before spawning, the choice of spawning areas and body size between wild and hatchery-reared salmon in the river Klarälven. Salmon behaviour in the river before spawning was analyzed using radio telemetry. The salmon were caught at Forshaga power plant, radio-tagged and returned to Klarälven at Ekshärad, 107 km from the river?s mouth.

Cannibalism can have major influence on fish population dynamics. A prerequisite for cannibalism is that the cannibal and the potential victim meet, and besides density effects, the encounter rate between cannibals and their victims is therefore also largely dependent on habitat use and habitat heterogeneity. In this study I quantified and compared the potential for cannibalism in stream-dwelling European grayling populations in three Rivers in Jämtland by means of habitat classifications. I also analyzed population dynamic consequences of varying the potential for cannibalism in terms of intensity, using a physiological structured population model. Findings based on habitat characteristics were that the potential for cannibalism is in general not favourable in these types of streams.