Anthropogenic alterations of nutrient inputs and food-web structure are two of the primary stressors affecting lake phytoplankton. This paper explores the independent and interactive effects of nutrients and food-web structure (as indexed by zooplankton size) on phytoplankton size structure by fitting time-series models to data from three lakes where both factors have been manipulated. I assess...

Using the common carp Cyprinus carpio L. in polyculture ponds to increase both phytoand zooplankton availability has become a popular practice for the cultivation of plankti vorous fish, such as rohu Labeo rohita Hamilton. However, the dynamics of how common carp influences the environment and ecology in polyculture ponds are unclear. In the present study, the effects of various stocking densit...

The taxonomic composition of phytoplankton responsible for primary production on continental shelves has changed episodically through Earth history. Geological correlations suggest that major changes in phytoplankton composition correspond in time to changes in grazing and seawater chemistry. Testing hypotheses that arise from these correlations requires experimentation, and so we carried out a...

Phytoplankton species show a variety in morphology which is the result of adaptations to pelagic life including responses to fluctuations in water column dynamics driven by weather conditions. This has been reported in the oceans and in Northern temperate lakes. In order to observe whether tropical freshwater phytoplankton responds to seasonal variation in weather, the weekly variation in tempe...

The potential of marine ecosystems to adapt to ongoing environmental change is largely unknown, making prediction of consequences for nutrient and carbon cycles particularly challenging. Realizing that biodiversity might influence the adaptation potential, recent model approaches have identified bottomup controls on patterns of phytoplankton diversity regulated by nutrient availability and seas...

A large bloom of Prymnesium polylepis occurred in the Baltic Sea during the winter 2007-spring 2008. Based on numerous reports of strong allelopathic effects on phytoplankton exerted by P. polylepis and its toxicity to grazers, we hypothesized that during this period negative correlations will be observed between P. polylepis and (1) main phytoplankton groups contributing to the spring bloom (i...

Mixing processes in lakes are key factors controlling light availability for phytoplankton growth, but understanding the contribution of mixing is often confounded by other factors such as nutrient availability and species dynamics. Our study examined this problem in a low pH, geothermally heated lake dominated by one phytoplankton genus and lacking the complexity of nutrient limitation, phytop...

We analyze the predictions of a reaction advection di usion model to pinpoint the nec essary conditions for bloom development of sinking phytoplankton species in strati ed waters This reveals that there are two parameter windows that can sustain sinking phytoplankton a turbulence window and a thermocline depth window The two win dows are delimited by four critical parameters a minimal and maxim...

Viruses influence the ecology and diversity of phytoplankton in the ocean. Most studies of phytoplankton host-virus interactions have focused on bloom-forming species like Emiliania huxleyi or Phaeocystis spp. The role of viruses infecting phytoplankton that do not form conspicuous blooms have received less attention. Here we explore the dynamics of phytoplankton and algal viruses over several ...

Dilution experiments were performed to quantify growth and mortality rates of phytoplankton groups (as defined by pigment markers) for 5 wk in an iron-induced phytoplankton bloom during the European Iron Fertilization Experiment (EIFEX) conducted in the Southern Ocean. Rates could be reliably measured for the 2 main groups, diatoms and prymnesiophytes. Mean phytoplankton intrinsic growth rates ...