Search for dissertations about: "food web"

Showing result 21 - 25 of 173 swedish dissertations containing the words food web.

2. 21. Hydroxylated polybrominat­ed diphenyl ethers in Baltic Sea biota : Natural production, food web distribution and biotransformation

   Author : Dennis Lindqvist; Lillemor Asplund; Walter Vetter; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; OH-PBDEs; Baltic Sea; Biosynthesis; Environmental fate; Wildlife exposure; Metabolism; Analytical methods; Ceramium tenuicorne; Blue mussel; Gammarus spp.; Stickleback; Perch; Grey Seal; miljökemi; Environmental Chemistry;

   Abstract : Hydroxylated polybrominated diphenyl ethers (OH-PBDEs) are naturally produced in aquatic ecosystems e.g. by algae. Many OH-PBDEs have been observed to be highly bioactive and to cause adverse effects through several pathways, e. READ MORE

4. 22. Effects of temperature and terrestrial carbon on fish growth and pelagic food web efficiency

   Author : Robert Lefébure; Ulf Båmstedt; Pär Byström; Stefan Larsson; Agneta Andersson; Lars-Gösta Rudstam; Umeå universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Attack rates; Bacterial production; Climate change; Critical resource density; Growth rates; Microbial food web; Three-spined stickleback;

   Abstract : Both temperature and terrestrial dissolved organic carbon (TDOC) have strong impacts on aquatic food web dynamics and production. Temperature affects vital rates of all organisms and terrestrial carbon has been shown to alter the dynamics of phytoplankton and bacterial production and affect the trophic structure of planktonic food webs. READ MORE

5. 23. Direct and indirect effects of fish predation and excretion in aquatic food webs

   Author : José Luiz Attayde; Biologiska institutionen; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; marine biology; Hydrobiology; zooplankton; resilience; predation; phytoplankton; nutrient enrichment; nutrient recycling; interaction strength; herbivory; food webs; food chain; excretion; fish; detritus; detritivory; aquatic ecology; limnology; Marinbiologi; limnologi; akvatisk ekologi; Ecology; Ekologi;

   Abstract : The aim of this thesis was to elucidate the mechanisms by which planktivorous fish can affect planktonic communities in lakes and how they may affect benthic communities through their effects on planktonic communities. In a laboratory experiment, nutrients released by fish increased algal biomass and altered phytoplankton community structure, suggesting that fish can affect phytoplankton by directly releasing nutrients. READ MORE

6. 24. The role of terrestrial and phytoplankton-derived organic matter in planktonic food webs

   Author : Anja Wenzel; Ann-Kristin Bergström; Tobias Vrede; Maarten Boersma; Umeå universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Daphnia; phytoplankton; heterotrophic bacteria; terrestrial particulate organic material; food quality; food quantity; fatty acids; oligotrophic; Light:Nutrient-Hypothesis; limnologi; Limnology;

   Abstract : Lakes are important global ecosystems and many of them are nutrient-poor (unproductive). Especially in northern boreal latitudes, lakes may be heavily subsidized by terrestrial organic material (t-OM) from peat layers in the catchment. READ MORE

7. 25. Multiple forces drive the Baltic Sea food web dynamics and its response to environmental change

   Author : Susa Niiranen; Thorsten Blenckner; Olle Hjerne; Mike Elliott; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Baltic Sea; climate change; Ecopath with Ecosim; food web interactions; multiple drivers; regime shift; trophic control; Marine Ecology; marin ekologi;

   Abstract : Understanding the interaction of multiple drivers and their compounded effects on ecosystem dynamics is a key challenge for marine resource management. The Baltic Sea is one of the world’s seas most strongly impacted by effects from both human activities and climate. READ MORE