Sökresultat:
1227 Uppsatser om Fish behavior - Sida 2 av 82
Pre-spawning habitat selection of subarctic brown trout (Salmo trutta L.) in the river Vindelälven, Sweden
Habitat selection of migratory brown trout at the upper reaches of River Vindelälven, wasstudied in September during the pre-spawning period. The fish migrate from down- orupriver lakes for spawning in the river and data was collected by habitat mapping andradio-telemetry. Habitat selection of fish was analysed with preference curves andstatistical modelling, using the physical variables; depth, stream velocity and streambedsubstrate. Preference curves were derived by comparing fish habitat use with their nearbyavailable environment while the statistical modelling aimed to answer three main questions.1) Do the trout have a specific preference of depth, water velocity and streambed substrate?2) Is there any difference in habitat selection between sexes? 3) Is there a shift in habitatselection over time? The preference curves indicated that trout favored water depths of 1-2m, velocity compositions characterized as glides (c.
Yngre pensionärers informationsbeteende i vardagslivet och på internetkurs.
The aim of this study is to examine the information behavior of younger seniors with a special focus on the Internet. Using a qualitative method consisting of a case study, including observations, diaries, questionnaires, and information diaries, we were able to compare the information behavior of the seniors in their use of the Internet, with the information behavior in their everyday life. The result of the study shows that the respondents led very active lives and used many different information sources in everyday life. They did not only seek information, but also assimilated it, often with a purpose to mediate it to other people. The motives behind the information use in everyday life were mainly connected to their life situations.
Vandring av vårlekande fisk och jämförelse av fångst mellan ryssja och strömöversiktsnät i Hammerstaån, Stockholms län
During the last two hundred years many wetlands and streams in Sweden have been lowered to provide land for agriculture and forestry. Some of the coastal wetlands and streams probably served as spawning sites for certain species of fish in the Baltic Sea, but the present situation is not well known. As standardized methods to monitor fish in running waters are carried out during late summer or autumn, there is a need for methods to sample spring-spawning fish in these streams.The aim of this study was to survey the lower kilometer stretch of Hammerstaån in Stockholm, to investigate the extent to which the stream is used by spring-spawning fish. Furthermore, the study aims to evaluate a new type of survey fishing gill net called strömöversiktsnät (SÖN). This was done by comparing the catch of fish by SÖN with that of fyke nets.
Konsumentbeteende vid köp av färsk fisk : en kvalitativ studie för utveckling av ett produktkoncept hos ICA
Health and convenience trends dominate the food industry and retailing business of today.
The health consciousness is spreading while appealing product attributes concerning taste and
packaging also are increasingly important. At the same time, the competition is growing fierce
in the Swedish market with hard discount formats and niche concepts who also are trying to
provide the market with perishables. Therefore, the pressure to lower prices is increasing
making economies of scale and rationalization progressively more important.
In 2004, ICA launched private label meat packaged in a modified atmosphere. Consequently,
many stores went from in-store cutting-up and packaging to selling centrally packaged and
distributed meat. ICA is now developing a concept with fresh fish in modified atmosphere
packages and needs to increase the knowledge about the market and the consumer.
What factors correlates with the use of game meat, wild fish, berries and mushroom in Swedish households : urban vs. rural areas
This study was made to see too what extent Swedes uses consumptive resources such as berries and mushrooms, game meat and meat from fish in their household on a yearly basis. I have also looked into the difference between rural and urban areas in Sweden. Further aim was to determine what factors that correlates with the participation in berry and mushroom picking and the use of game and fish meat within the household. The study was conducted in form of a mail survey that was sent to randomly chosen persons in every municipality in the six northern most counties in Sweden and in the county of Stockholm. In addition a sample was sent to randomly chosen persons on a national level.The results showed there is a difference in use between rural and urban areas in Sweden in all 4 investigated consumptive resources.
Hållbar vattenkraft i Nissan : En förstudie och konsekvensutredning över förutsättningarna för ökade vandringsmöjligheter med nya fiskvägar.
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.
Vandring av vårlekande fisk och jämförelse av fångst mellan ryssja och strömöversiktsnät i Hammerstaån, Stockholms län
During the last two hundred years many wetlands and streams in Sweden have been lowered to provide land for agriculture and forestry. Some of the coastal wetlands and streams probably served as spawning sites for certain species of fish in the Baltic Sea, but the present situation is not well known. As standardized methods to monitor fish in running waters are carried out during late summer or autumn, there is a need for methods to sample spring-spawning fish in these streams.The aim of this study was to survey the lower kilometer stretch of Hammerstaån in Stockholm, to investigate the extent to which the stream is used by spring-spawning fish. Furthermore, the study aims to evaluate a new type of survey fishing gill net calledströmöversiktsnät (SÖN). This was done by comparing the catch of fish by SÖN with that of fyke nets.
Utvärdering av rörelsemönster hos öring (Salmo trutta) utifrån otolitmikrokemi
The classic view of trout (Salmo trutta) life history is that trout begins its life in freshwater, migrates to the ocean after about 1-4 years and then returns to freshwater to spawn. As trout fry have been caught at the mouth of the River Emån, near the Baltic Sea, researchers have speculated that some trout emigrate during their first year of life. The purpose of this study was to describe the variation in the length of time trout reside in freshwater before they migrate to the ocean for the first time. Another purpose was to investigate whether it was possible to discern where and how long the fish spent in freshwater and saltwater during different parts of their lives. Between 2007 and 2009, 23 adult trout were captured in the River Emån in southeastern Sweden.
Gäddan & fisket i Ringsjöholm : en osteologisk metodstudie i säsong & bevarande
This paper presents the results from an osteological method study of the Ringsjöholm fishbone material. Ringsjöholm is located in Scania, southern Sweden and is 14C dated to 5960-5200 B.P. The aim of this paper is to critically analyse methods used on fish bone material in estimations of season. Three different approaches were used to estimate the fishing season at the Ringsjöholm settlement; 1) identified species, 2) size estimations of the pike based on Enghoffs (1994-95) regression formulae of os dentale, and 3) growth rings of the pike vertebrae.The identified species and the size estimations of the pike points to the fishing being active both during spring and summer. Growth rings analysis of the pike vertebrae didn?t give any quantitative results because of fragmentation.
Vermicompost for reduction of vegetable waste - and a possible means to produce fish feed in aquaponic systems?
Aquaponics is a food production system consisting of a consecutive cultivation of plants and aquatic animals, fish or shellfish, in recirculating water. The plants feed on the nutritious effluents from the fish tank and bacteria converts ammonia from the fish tank into nitrate that is absorbed by the plants. The plants receive nutrition and the fish gain purified water.
The environmental impact of the production of fish meal and fish oil used in conventional fish feed includes a large consumption of fossil fuels with subsequent carbon dioxide emission.
The aquaponic system can be made environmentally sustainable and self-supporting if supplemented with a vermicompost/vermiculture for the production of worm protein as a fish feed.
Vegetable waste from the hydroponic part of the system can be reused as worm feed in the compost and the protein rich worms can be harvested, dried and grinded and brought back to the aquaculture as fish feed.
As a first step in this direction, I have investigated the effect of recycling of vegetable waste in vermicomposts on the growth and number of earthworms (this was evaluated after harvesting).
The hypotheses were that earthworms can be cultivated in the vegetable waste and that by adding manure to the vermicompost it is possible to obtain a nutrient content adequate to support a continuous worm harvest, in other words create a vermiculture.
Eisenia fetida and Dendrobaena veneta were grown in 20 L bins containing peat mixed with either poultry or cattle manure. The proportions were 70% peat and 30 % manure. Discarded plant parts from lettuce cultivation was added to the vermicomposts (35 g per week) and water was supplied
with 0.8 L per week.
Utomhuspedagogik : En komparativ studie mellan teori och verklighet
ABSTRACTOur work deals with antisocial behavior among elementary school students between 7 and 16years in the school environment. The aim of our study was to examine how school personnelare experiencing antisocial behavior among students from a gender perspective. We were alsointerested to find out what the school's staff has of the experience of the differences andsimilarities between girls 'and boys' antisocial behavior. We used gender theory, when weanalyzed our individual responses to interview questions. We made six qualitative interviewswith low-and high school teachers, assistant principals, counselors and special educationteachers training in Kalmar County.
Lekens betydelse för social kompetens : Tre förskollärares erfarenheter
ABSTRACTOur work deals with antisocial behavior among elementary school students between 7 and 16years in the school environment. The aim of our study was to examine how school personnelare experiencing antisocial behavior among students from a gender perspective. We were alsointerested to find out what the school's staff has of the experience of the differences andsimilarities between girls 'and boys' antisocial behavior. We used gender theory, when weanalyzed our individual responses to interview questions. We made six qualitative interviewswith low-and high school teachers, assistant principals, counselors and special educationteachers training in Kalmar County.
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.
Beteendebubblan : En studie om navigationsbeteende på internet med fokus på korta navigationstillfällen
The purpose of this paper is to explore web use and web navigation behavior. This paper presents findings from qualitative research based on interviews and diarie studies. The basis of this study is Eli Parisers work about ?the filter bubble?. As personalization systems shape our experience of the web, based on who we are, our bubble of knowledge and information becomes smaller.
Gärningsmannaprofilering : Ett fungerande verktyg eller påhittad filmglamour?
Some children develop externalizing and internalizing behavior problems at an early age. Previous research has often treated these children as a homogeneous group, the purpose of this study is to show that this group of children is in fact heterogeneous. Data from theSOFIAstudy was used and preschool pedagogues were informants. The sample contained 2121 boys and girls between 3-5 years. Groups of children with the behavior problems and the risk factors AD/HD symptoms, fearlessness and callous-unemotional traits were created.