Search for dissertations about: "microzooplankton"

Showing result 1 - 5 of 7 swedish dissertations containing the word microzooplankton.

2. 1. Non-indigenous zooplankton : the role of predatory cladocerans and of copepods in trophic dynamics

   Author : Marc Andersen Borg; Fredrik Wulff; Markku Viitasalo; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Acartia tonsa; Bythotrephes longimanus; Cercopagis pengoi; egg production; fitness; food web changes; ingestion rates; invasive species; metabolic balance; mortality; non-indigenous zooplankton; predation impact; salinity tolerance; stable isotopes; Marine ecology; Marin ekologi; marin ekologi; Marine Ecology;

   Abstract : Human-mediated introductions of non-indigenous species now threaten to homogenize the biota of the Globe, causing huge economic and ecological damage. This thesis studies the ecological role of 3 invasive planktonic crustaceans, the omnivorous copepod Acartia tonsa (western Atlantic and Indo-Pacific) and the predatory cladocerans, Cercopagis pengoi (Ponto-Caspian) and Bythotrephes longimanus (Eurasian). READ MORE

4. 2. 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

5. 3. Temporal and spatial variation in the community composition of lake bacterioplankton

   Author : Eva S. Lindström; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Biology; bacterioplankton; freshwaters; 16S rDNA; DGGE; community composition; Biologi; Biology; Biologi; limnologi; Limnology;

   Abstract : Bacterioplankton are among the smallest and most abundant organisms in lake ecosystems. Due to the lack of relevant methods, the taxonomic composition of bacterioplankton has been studied less thoroughly than that of larger organisms. READ MORE

6. 4. 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

7. 5. Copepods in Skeletonema-dominated food webs : Toxicity and nutritional quality as factors controlling copepod-diatom interactions

   Author : Roswati Md Amin; Ulf Båmstedt; Sigrun Jónasdóttir; Umeå universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Copepod-diatom interaction; toxicity; nutritional quality; Skeletonema;

   Abstract : My thesis focuses on copepod-diatom interactions, specifically on the effects of food quality and toxicity on copepod feeding, reproductive success and behavior but as a frame, also includes a quantitative evaluation of copepod carbon requirements compared to other trophic plankton groups. My aim was to evaluate the function of copepods in diatom-dominated spring blooms. READ MORE