Diatoms are often a major food source for zooplankton and contribute significantly to vertical POC flux through sinking of dead cells, aggregates and zooplankton fecal pellets. The silica content of diatoms varies among different species and within a species growing under different environmental conditions and physiological status. However, to-date there has been no investigation of the effect ...

(e.g. seaweeds, barnacles). This coating adds significantly to the drag of large ships and thus increases fuel consumption. The only chemical solution known to prevent this from happening is tributyl tin, which was banned in the late 1980s on environmental grounds. Jim Callow at the University of Birmingham is among the very small number of people investigating this phenomenon and looking for n...

The present study aims at evaluating the impact of diatoms and copepods on microbial processes mediating nitrate removal in fine-grained intertidal sediments. More specifically, we studied the interactions between copepods, diatoms and bacteria in relation to their effects on nitrate reduction and denitrification. Microcosms containing defaunated marine sediments were subjected to different tre...

the present study reports the changes in the phytoplankton community structure in taklong island national marine reserve (tinmar), guimaras island, philippines. quantification of pah yielded undetectable results, whereas, primary productivity, phytoplankton density, and diversity values were higher as compared to samples before the oil spill and samples from the reference site. sixty-nine gener...

Detection of diatoms in tissues has been applied as an important sign of drowning since the beginning of 20th century and utility of diatoms for the diagnosis of drownings cases was debated soon after they were first found in lung exudates. Hard bones (sternum and femur) and soft tissues (lungs and liver etc) of drowned bodies are usually sent to the Forensic Science Laboratories for the detect...

Temporary cysts enables long-term dark survival of Scrippsiella hangoei (Dinophyceae). – Submitted manuscript. and pH during a sub-ice bloom of dinofl agellates in the Baltic Sea. – Submitted manuscript. The printed research article included in this thesis (paper I) is reproduced with the kind permission of Oxford University Press. Increased anthropogenic loading of nitrogen (N) and phosphorus ...

Diatoms microalgae produce biosilica nanoporous rigid outershells called frustules that exhibit an intricate nanostructured pore pattern. In this paper two specific Thalassiosira weissflogii culture conditions and size control procedures during the diatoms growth are described. Data from white field and fluorescence microscopy, evaluation of cell densities and cell parameters (k value and R val...

In vast expanses of the oceans, growth of large phytoplankton such as diatoms is limited by iron availability. Diatoms respond almost immediately to the delivery of iron and rapidly compose the majority of phytoplankton biomass. The molecular bases underlying the subsistence of diatoms in iron-poor waters and the plankton community dynamics that follow iron resupply remain largely unknown. Here...

The study of diatoms has diversified strongly since its beginnings in the 18th century. Early work focused upon collecting material for taxonomic analysis but by the mid 19th century a strong global perspective had already developed. In the 20th century, use of diatoms in biostratigraphy, environmental change and ecology and in biogeography proliferated as did work on diatom ultra structures, l...

In spite of the high abundance and species diversity of diatoms, only a few bioactive compounds from them have been described. The present study reveals a high number of mammalian cell death inducing substances in biofilm-associated diatoms sampled from the intertidal zone. Extracts from the genera Melosira, Amphora, Phaeodactylum and Nitzschia were all found to induce leukemia cell death, with...