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Hittade 5 uppsatser som matchar ovanstående sökkriterier.
1. Novel Scale Chemistry of Salmo Salar L. : New Linkage of Otolith and Scale Chemistry to M74 Reproductive Disorder
Master-uppsats, Uppsala universitet/Institutionen för medicinsk biokemi och mikrobiologiSammanfattning : Baltic salmon suffer from maternally transmitted M74 reproductive disorder, which causes yolk-sac fry mortality due to thiamine deficiency. This study investigates trace elemental analyses of Baltic salmon applied on otoliths and scales and their possible link to identifying M74. LÄS MER
2. Otolith morphology of sprat (Sprattus sprattus) along the Swedish west coast
Master-uppsats, SLU/Dept. Of Aquatic ResourcesSammanfattning : The population structure of sprat (Sprattus sprattus) in the Swedish Kattegat – Skagerrak has been at present not well investigated, and the boundaries between the management unit in this region and the larger stock occurring in the North Sea are also highly uncertain, posing issues to the successful management of the stock in this area. In this study, variations in otolith shape among several samples from the Swedish west coast, southern North Sea and Norwegian fjords north of Bergen were studied to investigate the effectiveness of shape analysis for characterise the population structure in the study area, and evaluate whether differences could be used to assign individual fish to their origin. LÄS MER
3. Northern pike Esox lucius growth rates in sub populations of freshwater and sea water origins in the Baltic Sea : Otolith method approach
Master-uppsats, Linnéuniversitetet/Institutionen för biologi och miljö (BOM)Sammanfattning : Northern pike or pike Esox lucius is total piscivorous fish species found in the brackish and freshwater ecosystems of the Northern hemisphere. It is a top predator and keystone species that causes cascading effects in these ecosystems. Otoliths have been used to estimate age and growth rates in most fishes. LÄS MER
4. Assessing the importance of freshwater tributary systems for the recruitment of Eurasian Perch (Perca fluviatilis) in Baltic Sea Coastal Ecosystems
Master-uppsats, SLU/Dept. Of Aquatic ResourcesSammanfattning : Populations of one of the most important predatory fish species within Baltic Sea coastal ecosystems, the Eurasian Perch (Perca fluviatilis), have declined in some coastal areas during recent decades. This has caused negative effects on an ecological, commercial, and cultural scale, and protection and restoration of recruitment areas (perch spawning grounds) are believed to be an important player in supporting future stocks. LÄS MER
5. Utvärdering av rörelsemönster hos öring (Salmo trutta) utifrån otolitmikrokemi
Magister-uppsats, Karlstads universitet/Fakulteten för hälsa, natur- och teknikvetenskap (from 2013)Sammanfattning : 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. LÄS MER
