124 uppsatser · sida 3 av 9
… possible. Wheat bran was used to balance the fiber content of the diets. The fish were fed a restricted diet two times a day. Protein digestibility was higher for fishes fed control- and low diets (>900 g/kg DM) than for fishes fed high diet (P < 0, 01), the group fed medium …
High levels of Hg in fish in Swedish lakes have been a problem along time in Sweden. The major concern is production and accumulation of the most toxic form of mercury; methyl mercury (MeHg). Consequently, in about half of our 83 000 lakes fish contain concentrations above the …
how to communicate water benchmarks to stakeholders
Global catch fishery is said to been oppressed to its limit (Boyd & Schmittou, 1999), further implying aquaculture might be the only solution to the world demand for fishery products. The applied term aquaculture in this paper refers to the one used by NOAA (2008); breeding …
En utvärdering av laxfällan vid vattenkraftverket i Forshaga
Many watersheds have lost stocks of migrating fish species because of the development of hydroelectric plants and other fragmenting barriers. The remaining stocks of migrating Atlantic salmon (Salmo salar) and brown trout (Salmo trutta) in River Klarälven, Sweden are five times …
… elements. The biological elements in both lakes and streams are fish and benthic macroinvertebrates. The chemical elements in lakes consist of total phosphorus, total nitrogen, quotient total nitrogen/total phosphorus, chemical oxygen demand, alkalinity and pH-value. The …
… Spexhultasjön is a moderate humic mesotrophic lake that is not acidified. The fish fauna was investigated by using a standard method for sampling freshwater fish with multi mesh gill nets. The fish fauna was diverse with perch, pike, tench, common whitefish, and roach. Perch and …
Perch (Perca fluviatilis) is a very popular fish in Sweden and it is common in Swedish waters. In some areas along the Swedish coast the perch population has decreased. It is therefore important to get a view at the health status of perch. During April, July and August of 2008 …
… give a higher temperature that could result in a longer growing season for the fish. Cultivated smolt is today bigger than it was before, it is also bigger than the wild salmon. The growth season of salmonids depend on the water temperature, salmonids need 6-80C to grow. Water …
… in order to study the outcome of translocations. This was carried out with FISH (fluorescence in situ hybridization) -technique. Fluorochrome-labelled probes hybridize to each side of the breakpoint of the MALT1-gene and the result is studied in a fluorescence microscope.The …
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 …
passage fates at a reservoir, a power house and a bypass structure
… 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 …
… 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 …
… for understanding sudden changes in ecosystems. I examined the predation from fish and waterfowl on benthic invertebrates in the shallow and eutrophic Lake Tåkern in the plains of Östergötland County, southern Sweden. The study was experimental and used exclosures (three types …
… wetlands and watercourses. Earlier studies lack an examination concerning how fish- and waterfowl predation affect macroinvertebrates during shorter periods in the spring. I performed an exclosure study in the shallow eutrophic Lake Tåkern which is located in the western part of …
Dagsläge och framtidsplaner
… plants. The owners rank economy, new environmental ruling, requirements for fish ways and lack of time as the biggest challenges. The owners' concern about the new environmental ruling ispreceded by a debate on the subject in which some County Boards (Länsstyrelser) raised …
