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128 Uppsatser om Brown trout - Sida 2 av 9
Flottledsåterställning i norra Sverige: : effekter på habitatkvalitet och populationstätheter av juvenil öringar (Salmo trutta L.)
In an effort to evaluate the effects of restorations of float ways on population density of stream dwelling fish in relation to the changes in habitat, I studied the physical habitat restored and channalized sites and their population density of Brown trout (Salmo trutta L.) in three streams in the municipality of Sorsele.
The differences between the channalized and the restored sites where most noticeable regarding substrate which where generally coarser in the restored sites. The analyses showed that the proportion of habitat that where suitable to the age class 0+ where significantly lower in the restored sites compared to the channalized sites. Regarding age class ?2+, no statistical differences in habitat quality were found.
Effektivisering av urvalsprocesser vid analysering av björnspillning : Ett förslag till den svenska förvaltningen av brunbjörn Ursus arctos
The aim with this report is to formulate a strategic method to optimize selection processes of DNA-samples from a faeces inventory to identify as many individuals in as few analyzes as possible, and by that keep down the costs of brown bear management. Brown bear management in Sweden founds today on results from faeces inventory and is substantially led by the county administration boards. Data from the years of 2004 and 2009´s inventories in Västerbotten was used to test and evaluate different methods in selection processes of which faeces that should be sampled. Comparison were made between making selection by chance, by spatial distribution and by calculating variations in logistic regressions coefficient b, in other words bear density and probability in finding same individual in several faeces. We can show making selection by chance is the most uncertain method.
Effekt av parasitinfektion på öringens furagering
Parasiter kan påverka sina värdar på många olika sätt. Flodpärlmusslans (Margaritifera margaritifera L.) glochidielarver lever inkapslade som parasiter på gälarna hos öring (Salmo trutta L.) i flera månader innan de blir frilevande. Genom experiment i ett strömakvarium har denna studie undersökt hypoteserna att öring med inkapslade gälparasiter tar färre byten, och simmar kortare avstånd när de födosöker än öring utan gälparasiter. Resultaten visade att infekterad öring tog signifikant färre byten/minut än oinfekterad öring både i början och i slutet av en födosöksperiod under vilken individerna konfronterades med tvåhundra poteniella byten. Vilket visar att infekterad öring har en lägre furageringshastighet är oinfekterad öring. Däremot påvisades ingen skillnad mellan öring med och utan parasiter med avseende på antal byten tagna i förhållande till avstånd från bytet. Den lägre furageringshastigheten som påvisades hos de infekterade öringarna tyder på att infektion av flodpärlmusslans larver kan ha negativa effekter på fiskarnas tillväxt, och därmed överlevnad.
Kantzonsvegetationens inverkan på dieten hos öring (Salmo trutta) i en skogsbäck
Effekterna på öringens (Salmo trutta) diet till följd av en avverkning av kantzonsvegetationen har undersökts i ett fältexperiment, där två av de potentiella effekterna av en skogsavverkning simulerades. Fokus låg på de två faktorerna ökad ljusinstrålning och minskat nedfall av terrestra evertebrater. Ökad ljusinstrålning har simulerats med hjälp av montage av lysrör och nedfall av terrestra evertebrater med hjälp av plasttält. Frågeställningarna rör andelen terrester föda i olika behandlingar och årstider, dietskillnader mellan äldre och yngre öringindivider, skillnader i mängden akvatisk föda vid ökad ljusinstrålning samt en taxonomisk översikt av dietens sammansättning. Signifikanta skillnader mellan behandlingarna fanns, där individerna i kontrollbehandlingen åt signifikant mer terrester föda än individer i tältbehandlingen och den kombinerade tält- och ljusbehandlingen.
Kantzonsvegetationens inverkan på dieten hos öring (Salmo trutta) i en skogsbäck
Effekterna på öringens (Salmo trutta) diet till följd av en avverkning av kantzonsvegetationen har undersökts i ett fältexperiment, där två av de potentiella effekterna av en skogsavverkning simulerades. Fokus låg på de två faktorerna ökad ljusinstrålning och minskat nedfall av terrestra evertebrater. Ökad ljusinstrålning har simulerats med hjälp av montage av lysrör och nedfall av terrestra evertebrater med hjälp av plasttält. Frågeställningarna rör andelen terrester föda i olika behandlingar och årstider, dietskillnader mellan äldre och yngre öringindivider, skillnader i mängden akvatisk föda vid ökad ljusinstrålning samt en taxonomisk översikt av dietens sammansättning. Signifikanta skillnader mellan behandlingarna fanns, där individerna i kontrollbehandlingen åt signifikant mer terrester föda än individer i tältbehandlingen och den kombinerade tält- och ljusbehandlingen.
Millennium Mindscreen - Om det filmiska jaget och den samtida förstapersonsfilmen
Denna uppsats diskuterar, utifrån relevant teori inom narratologin, det filmiska förstapersonsberättandet och dess konstruktion. Med utgångspukt i en synkron studie av ett antal förstapersonsfilmer (Where the Truth Lies, Millennium Mambo, The New World, The Thin Red Line, The Brown Bunny, Eyes Wide Shut och L'Intrus) diskuteras vilka implikationer dessa filmer har för filmteori rörande just det subjektiva berättandet och om det i någon egentlig bemärkelse finns en filmisk motsvarighet till det litterära "jaget"..
Freshwater pearl mussel as indicators of Swedish streams - a comparison between freshwater pearl mussel and biological quality elements
The freshwater pearl mussel (Margaritifera margaritifera) is a large freshwater mussel. Because of its sensitivity to human impact, such as eutrophication, acidification and alterations of hydromorphology, the species is considered as a robust indicator of stream water quality and biodiversity. Moreover, due to the species complex life cycle, including a larval stage on the gills of salmon and trout, and sensitivity of early life stages, regeneration is often used as an indicator. The freshwater pearl mussel is also used in the expert judgement of status classification of benthic invertebrates according to the European Water Framework Directive.
The purpose of this study was to gain a deeper understanding of the freshwater pearl mussel as an indicator for Swedish streams. It was made with two types of
association analyses.
Listeria monocytogenes i vakuumförpackad lax :
Listeriosis, which is caused by Listeria monocytogenes, is a rare food borne disease that primarily affects people whose immune system is weakened. These may be elderly people, pregnant women, new-born infants and individuals on immunosuppressive medication. The most common symptoms are meningitis, septikemia and abortion. The mortality is high, on average 20-30 %.
In recent years the number of cases in Sweden has increased.
The influence of forestry stands treatments on brown bears (Ursus arctos) habitat selection in Sweden ? an option for Alberta forestry?
The brown bear population in Alberta, Canada has been decreasing, while the Swedish has been increasing and all the affecting parameters are not known. This study examined the difference in these populations to see if an explanation could be found in differences between the forest management. The aim of the paper was to see if stand treatments had an influence of brown bears habitat selection in autumn in Sweden and how the results can be used in Alberta. This was done by analyzing bear positions in Sweden with forest data, and comparing forest management data for the study area in Sweden with forest management data for Alberta. The results displayed that mature forests over 60 years that have been commercially thinned are selected by bears rather than forests over 60 years that have not been commercially thinned in.
Brown bear (Ursus arctos) den site concealment in relation to human activity in Scandinavia
As a hibernating species, the brown bear spend most of the winter months in a den as astrategy to avoid unfavorable conditions. The denning period is a vulnerable time for bears,making them unable to flee disturbances without losing valuable amounts of energy. Brownbears' wariness of humans and avoidance of anthropogenic disturbance often steer denningbears away from human infrastructure, and bears thereby avoid possible disturbance and itsassociated energetic costs. This study was carried out to test the hypothesis that bearsdenning closer to infrastructure select more covered den sites to compensate for the closedistance. Dens from 32 individuals were visited and analyzed in terms of sighting distance(a measurement for den horizontal cover) and habitat ruggedness, in relation to distances toinfrastructure.
Brunbjörnens (Ursus arctos) inverkan på den nya svenska älgförvaltningen
The European Brown bear (Ursus arctos) has gone from basically being extinct in Sweden to, 2008 being estimated to a total of 3298 individuals. When looking at the new Swedish moose management system it is important to have an ecosystem-based approach and therefore include all the parts that moose impacts on and from in the management, especially the brown bear. Primarily in the spring and early summer the brown bear is a significant predator on moose calfs which must be taken into account in moose management. When the bear recolonize areas that it has previously been eradicated from, it will once again come in contact with people who are not accustomed to the bear's role in the ecosystem. We studied three groups of moose management areas with different predation by bears.
Vilka stereotypier finns hos brunbjörn (Ursus arctos), lodjur (Lynx lynx) och varg (Canis lupus) i djurpark och vilka berikningar finns? : förslag och rekommendationer om berikningar utifrån djurens beteendeekologi
The purpose of this work was that with the help of a literature review have a single document with information on how the various species: brown bear (Ursus arctos), lynx (Lynx lynx) and the wolf (Canis lupus) living in the wild. The aim was also to show which stereotypic behaviours these different species have in zoos and the enrichments that is already being used and to make suggestions and recommendations on enrichment based on animal behaviour ecology. In zoos, some species thrive well while others have propositions to propagating problems, poor health and stereotypic behaviors. The brown bear, lynx and wolf, live both in the wild and in zoos in Sweden. As these animals have different ways of living in the wild, it is important to accommodate to each species, the way they are kept in zoos in accordance with their behavioural ecology.Brown bears are omnivorous and solitary living species with large energy needs so that they spend most of their day to actively feeding but also rest.
Patologiska förändringar och säsongsmässiga variationer i testiklar från svenska brunbjörnar (Ursus arctos) :
Functioning reproductive organs are essential for the survival of a species. The reproductive system is very sensitive to exposure of chemical substances of anthropogenic origin. Humans release great amounts of chemical substances to the environment by our means of life and these substances have been proved to have a negative effect on the reproductive ability of different vertebral classes. In the polar bear (Ursus maritimus) a declined reproductive ability as an effect of decreased testosterone levels and decreased testicular size has been connected to the presence of high levels of organohalogenic compounds like PCBs. Although the Swedish brown bear (Ursus arctos) is not as carnivorous as its close relative the polar bear it is still exposed to environmental.
Vedrötor i stadsträd : biologi, detektionsmetoder och förebyggande åtgärder
Urban trees have very little in common with trees on natural sites, such as forests or pastures. Trees in urban environments are often planted in packed soil and in small volumes. This can lead to decreased availability of water and oxygen, as well as deteriorated ability for the soil to store nutritional elements. Also above ground the tree usually have limited space in cities. Regulations on free height over roads and cycle tracks demands high stems at an early stage of their development.
Attacks on humans in Sweden by bear, wolf, lynx, wolverine, moose and wild boar in relation to Swedes? fear for these animals
It is not easy to understand people?s fears since they are not always a logical reflection of the danger in certain situations. This study is an attempt to give a scientific view of the potential danger that certain animals in Sweden pose and compare this to Swedes? fear of these animals. A report shows that Swedes? have a certain amount of fear for being attacked by a wild animal in the forest and this fear has increased for certain animals over the last years.