Due to exploitation of the world?s rivers, the upstream migration of anadromous species is frequently delayed or even prevented. To mitigate these problems and allow fish to migrate past obstacles, structures such as fish ladders have been developed. However, recent studies show that many of the present Fish passage facilities are deficient. Monitoring and evaluation of passage facilities is therefore crucial to enable necessary adjustments.

A large number of rivers in northern Sweden have hydropower developments that cause negative effects on both up- and downstream migrations of anadromous species like Atlantic salmon. So far, most attention has focused on the hindrances of adult fish during their upstream spawning migration. However, since turbines in power stations cause losses on downstream passing fish, the focus on negative effects on smolts has increased. The aim of this study was to compare three different causes of losses of salmon smolts passing downstream through a power station area in the flow-controlled River Åbyälven in northern Sweden.A total of 61 wild salmon smolts were caught and radio-tagged in the River Åbyälven during their downstream migration in June 2009. The salmon smolts were released at three locations, 1.1 km upstream from the power station, in the turbine intake and in the upper part of a fishway, acting both for up- and downstream Fish passage.

The hydropower from Nissan River is of national interest and produces annually 230 GWh from the twelve power stations in the main flow. For modified waters a consideration between the power production and the biological values has to be made. This reports serves as a pre-study for Nissans Vattenråd. It tries to evaluate some of the biological values in the Nissan basin and map the power production in the area. And the size and value of lost power production from new fishways for the twelve stations in the main flow.The investment of new fishways is calculated using simplified templates with values from the business.

The life cycle of the anadromous Atlantic salmon (Salmo salar) can span large geographic, political, and socio-economic boundaries. Management strategies and regulations that only concentrate on small spatial scales often overlook larger basin-wide problems, especially relating to post-spawn seaward migration. In this master thesis one entire migration cycle of wild adult Atlantic salmon in the unregulated northern Swedish river Vindelälven was monitored by radio-telemetry tracking during upstream spawning migration and downstream seaward migration back to the Baltic Sea. The effect of ladder passage variables (time to pass, total time in the ladder, passage day over the ladder) at a fish ladder downstream in the river Umeälven, as well as fish size, were evaluated to determine if differences in upstream migration distance in the river Vindelälven could be observed. Ladder passage variables did not affect migration distance, but size exhibited a negative relationship to migration distance.

During the migration season in 2013 a study on spawning migrating salmon and the effect of water flow on the behavior was conducted of the salmon at the Forshaga hydropower station in the River Klarälven. The River Klarälven with its nine hydropower plants on the Swedish side, constituting migration obstacles for the migrating salmon. Fortum Generation AB has together with the County Administrative Board restored a salmon trap at the lowermost hydropower station in Forshaga, aiming at making it possible for the salmon to swim into the trap, and thereafter be transported by truck past the power plants and then continue their journey to the spawning grounds on their own. Unfortunately, it is believed that the trap does not work as well as it should. In this study, I focused on salmon position in relation to water flow and if the number of salmon that swam into the fish trap differed between salmon with previous experience of the trap (experienced) and salmon without experience (unexperienced).

The aim of this review is to assess the ethical implications of aquaculture, regarding fish welfare and environmental aspects. The aquaculture industry has grown substantially the last decades, both as a result of the over-fishing of wild fish populations, and because of the increasing consumer demand for fish meat. As the industry is growing, a significant amount of research on the subject is being conducted, monitoring the effects of aquaculture on the environment and on animal welfare. The areas of concern when it comes to animal welfare have here been divided into four different stages: breeding period; growth period; capturing and handling; and slaughter. Besides these stages, this report includes a chapter on the current evidence of fish sentience, since this issue is still being debated among biologists.

This thesis evaluates the environmental performance of six different fish farming systems. The thesis is part of the network group ?Hållbar fiskförsörjning I Stockholms län? (HFFS) which tries to increase the domestic and regional production of fish in Stockholm and move to a more sustainable supply in the Stockholm county. Two of the chosen systems; pangasius from Vietnam and salmon from Norway are delivering a substantial part of the fish consumed in Stockholm today, although they are very different when it comes to system characteristics. One system, arctic char with conventional feed, is produced in a fairly small scale in the north of Sweden, while the three remaining systems are viewed upon as possible options to supply Stockholm with fish in the future.

The purpose of this paper was to analyze fishbones from the Pitted Ware Culture settlement named Hemmor. in Dalbo, När parish on Gotland. The fishbones are unburnt and derive from one specific culture layer (c:6) in trench one VI:7, and radiocarbon dated to 2600-2300 BC cal.In this paper I wanted to answer these following questions:1. What kind of fish species did they eat in Hemmor?2.

A study was made to evaluate how current measurementscould help to determine how particles from fish farms are dispersed. During sixweeks of the summer 2012, two different current measurements were conducted.One of them consisted of measurements each fifth minute at 5 m and 15 m atthree locations for 14-16 days each. The other consisted of profilemeasurements at each location at four times during the period of six weeks. Forthe current measurements two instruments (model RCM 9) were used. A two weekmeasurement can give enough data to make an evaluation of how the currents at alocation will transport litter from a fish farm.

Fish-Bird är ett pågående vetenskapligt/konstnärligt projekt som genomförs i samarbetemellan konstnären Mari Veloni och Australien Center for Field Robotics. I korthet bestårprojekt av två robotar i form av rullstolar som interagerar med varandra och sinomgivning. Robotarna heter Fish respektive Bird och därav projektnamnet Fish-Bird.Detta examensarbete utvärderar Fish-Birds navigeringssystem. Bakgrunden tillutvärderingen är en oklarhet i huruvida navigeringssystem är ofullständigt eller felaktigt.Navigeringssystemet har visat bristande funktionalitet vid upprepade tillfällen. En stordel av problematiken förekommer oftast när hinder befinner sig nära varandra.Studien är gjord genom en detaljerad analys av Fish-Birds navigeringssystem.

The aim with this thesis came out of a strong interest for Passage Retrieval. Our intention has not been to evaluate an IR-system. Instead our goal has been to analyze the result of indexing documents and their passages. We have been studying the weights of the different terms in the different indices, in comparison with other parameters like frequency, normalized frequency and the inversed document frequency. Further more we have been looking at how the weights are spread using for instance the standard deviation.

Scintigraphic examination of the esophagus has for some time been the method of choice for the study of motility dysfunction in humans. The method has not yet been described for horses hence the lack of reference values for passage time for a bolus through the esophagus in healthy subjects. The purposes of this study were to measure passage velocity and time for a bolus to pass through the esophagus in healthy subjects, as well as to evaluate the reproducibility of the method. Eight warm-blooded trotters were used in the study. The horses were sedated with a low dose of Acepromazine prior to onset of the study.

Vaccination of fish can be assumed to cause pain. This study was designed to see if we can minimize the suffering of fish following vaccination. Fishes are cold-blooded animals and thus more primitive than warm-blooded animals. Despite this, many organs, e.g. the nervous system, have the same basic structure as that of other vertebrates. The fibre system for conducting pain is more diffuse than in humans.

The Arctic region is rich in natural resources such as oil, gas, minerals and fish. Climate change causes the Arctic ice melt, making resource extraction possible as well as opening up new transport routes through the Northwest Passage and the Northeast Passage. This has led to competition and cross-border strife among the Arctic States. The two largest states in the Arctic are Russia and Canada, which are also members of the Arctic Council. Russia and Canada are at the moment involved in several disputes regarding the Arctic territory where the ownership of the North Pole is one example.

SummaryIn the area to the east of Hue city, in Vietnam, lays Tam Giang lagoon, one of Asia's largest lagoons, with an area of 22,000 hectares. This lagoon is suitable for aquaculture. One reason for this is because the salinity differs from sweet to salty in different parts of the lagoon. The Vietnamese Government advocates an increase in environmentally-friendly aquaculture and the fish Siganus guttatus (Rabbit fish) is a candidate for this. This fish eats mainly algae and can be cultivated in a polyculture.