Sökning: "Sture Hansson"
Visar resultat 1 - 5 av 15 avhandlingar innehållade orden Sture Hansson.
Sammanfattning : .... LÄS MER
Sammanfattning : This thesis was written within the framework of a biomanipulation project where young-of-the-year (YOY) pikeperch (Sander lucioperca) were stocked to a Baltic Sea bay to improve water quality through a top-down trophic cascade. The aim of my doctorial studies was however focused on a broader ecological question, namely predation (the main driving force in a biomanipulation). LÄS MER
Sammanfattning : Human mediated transfer of non-indigenous species is considered to be a major threat to global biodiversity. The Ponto-Caspian round goby (Neogobius melanostomus), which has established populations in various regions in Eurasia and North-America, was first observed in Gulf of Gdańsk, Baltic Sea, in 1990. LÄS MER
Sammanfattning : Pelagic fish distribution and diel behaviour patterns were studied in coastal areas in the north-western Baltic Sea Proper to understand more about how fish distribution and behaviour might affect planning and analyses of results of hydroacoustic surveys (Papers I and II). The vertical distribution of fish at night from spring to autumn showed seasonal and annual trends that could be explained by predictable and consistent seasonal changes, e. LÄS MER
Sammanfattning : Fisheries agencies around the Baltic Sea use hydroacoustics to assess stock sizes of herring and sprat. These assessments rely on the assumption that the acoustic properties of Baltic clupeids are the same as North Sea herring. LÄS MER