Sökning: "young-of-the-year fish"

Visar resultat 1 - 5 av 12 avhandlingar innehållade orden young-of-the-year fish.

1. 1. The role of young-of-the-year fish in lake ecosystems

   Författare :Pia Romare; Biologiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Hydrobiology; Rutilus rutilus; Perca fluviatilis; diet-dependent growth; density dependent growth; behavioural cascade; 0 fish behaviour; horizontal echo sounding; biomanipulation; trophic cascade; predation pressure; young-of-the-year fish; trophic interactions; marine biology; aquatic ecology; limnology; Marinbiologi; limnologi; akvatisk ekologi; Ecology; Ekologi;

   Sammanfattning : Food chain theory is based on consumption; that is, presupposing that the only important interaction between organisms is that they actually meet in an unstructured environment and that one of them is consumed. Recently, studies, including biomanipulation projects, have indicated that trophic interactions are more complex than predicted by food chain theory. LÄS MER

3. 2. Climate change impacts on production and dynamics of fish populations

   Författare :Per Hedström; Pär Byström; Jan Karlsson; Peter Eklöv; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Temperature; terrestrial dissolved organic carbon; light extinction; GPP; recruitment; winter mortality; metabolism; cohort competition; fish production; fish biomass;

   Sammanfattning : Ongoing climate change is predicted to increase water temperatures and export of terrestrial dissolved matter (TDOM) to aquatic ecosystems influencing ecosystem productivity, food web dynamics and production of top consumers. Ecosystem productivity is mainly determined by the rates of primary production (GPP) in turn controlled by nutrients, light availability and temperature, while temperature alone affect vital rates like consumption and metabolic rates and maintenance requirements of consumers. LÄS MER

4. 3. Distribution and activity of pelagic fish - acoustic studies in the Baltic Sea

   Författare :Tomas Didrikas; Sture Hansson; Thomas Mehner; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Pelagic; fish; hydroacoustic; distribution; activity; Baltic; Biology; Biologi;

   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

5. 4. Assessment of dietary patterns and prey consumption of marine mammals: Grey seals (Halichoerus grypus) in the Baltic Sea

   Författare :Karl Lundström; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; grey seal; Halichoerus grypus; Baltic Sea; diet; predation; fish; consumption; fatty acid signature analysis; bioenergetics; foraging ecology;

   Sammanfattning : The Baltic Sea has been severely affected by pollution and resource overexploitation during the last centuries. The grey seal (Halichoerus grypus) is a good example of how a species can be affected by such changes. LÄS MER

7. 5. Fine stream wood : effects on drift and brown trout (Salmo trutta) growth and behaviour

   Författare :Åsa Enefalk; Eva Bergman; Anders Nilsson; Stanley Gregory; Karlstads universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; stream fish; wood; salmonid; trout; aquatic invertebrates; behaviour; sheltering; Biology; Biologi;

   Sammanfattning : Stream ecosystems and their riparian zones have previously been regarded as two different ecosystems, linked through numerous reciprocal subsidies. Today, ecologists agree that the stream and the riparian zone should be regarded as one system, the stream-riparian ecosystem, which is characterised largely by the subsidies between land and water. LÄS MER