Search for dissertations about: "marine species"

Showing result 21 - 25 of 339 swedish dissertations containing the words marine species.

2. 21. Late Eocene through Oligocene calcareous nannofossils from the paleo-equatorial Pacific Ocean – taxonomy, preservation history, biochronology and evolution

   Author : Teodora Blaj; Jan Backman; Jorijntje Henderiks; Isabella Raffi; Paul Bown; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; marine sediments; calcareous nannofossils; late Eocene; Oligocene; biochronology; evolution; morphometry; taxonomy; ODP Leg 199 Site 1218; paleo-equatorial Pacific Ocean; Historical geology and palaeontology; Historisk geologi och paleontologi; Marine Geoscience; marin geovetenskap;

   Abstract : This study aims to unravel the ecological and evolutionary dynamics within the calcareous nannofossil communities at the Eocene/Oligocene (E/O) transition and during the Oligocene time when Cenozoic 'icehouse' conditions were established. The main question this study aims to answer is whether the changes in the nannofossil assemblages were controlled by intrinsic evolutionary trends or if the changes were controlled by environmental factors such as changes in temperature and nutrient availability in the surface water. READ MORE

4. 22. Species interactions and energy transfer in aquatic food webs

   Author : Jens Munk Nielsen; Monika Winder; Sture Hansson; Michael T. Brett; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Aquatic food webs; zooplankton; stable isotope analysis amino acids; molecular diet analysis; Marine Ecology; marin ekologi;

   Abstract : Food webs are structured by intricate nodes of species interactions which govern the flow of organic matter in natural systems. Despite being long recognized as a key component in ecology, estimation of food web functioning is still challenging due to the difficulty in accurately measuring species interactions within a food web. READ MORE

5. 23. Gastrotricha of Sweden - Biodiversity and Phylogeny

   Author : Tobias Kånneby; Ulf Jondelius; M. Antonio Todaro; Sven Boström; Rick Hochberg; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; taxonomy; systematics; phylogeny; new species; cryptic species; Chaetonotidae; Dasydytidae; Thaumastodermatidae; Systematic Zoology; zoologisk systematik och evolutionsforskning; Livets mångfald;

   Abstract : Gastrotricha are small aquatic invertebrates with approximately 770 known species. The group has a cosmopolitan distribution and is currently classified into two orders, Chaetonotida and Macrodasyida. The gastrotrich fauna of Sweden is poorly known: a couple of years ago only 29 species had been reported. READ MORE

6. 24. The effects of crayfish on interactions in freshwater benthic communities

   Author : Per Nyström; Biologiska institutionen; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; exotic species; trophic cascades; omnivory; crayfish; Trophic interactions; freshwater; Hydrobiology; marine biology; aquatic ecology; limnology; Marinbiologi; limnologi; akvatisk ekologi;

   Abstract : This thesis examines how freshwater crayfish affect community interactions in benthic food webs. I have mainly studied the influence of the introduced signal crayfish (Pacifastacus leniusculus) on littoral communities, but also the influence of the native noble crayfish (Astacus astacus). READ MORE

7. 25. The impact of cormorant nesting colonies on plants and arthropods

   Author : Gundula S. Kolb; Peter Hambäck; Lenn Jerling; Post David; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; seabirds; cormorants; islands; nitrogen; phosphorus; plants; arthropods; δ15N; Baltic Sea; ecological stoichiometry; species richness; species composition; numeric response; Biology; Biologi; Plant Ecology; växtekologi;

   Abstract : Seabirds concentrate large amounts of marine nutrients on their nesting islands. This nutrient input can have large consequences for island food webs and community structure. The high nutrient load may also cause runoff into surrounding waters and affect marine communities. READ MORE