Furthermore, the simulation with a wind of 10 m s−1 speed and of 48 hours’ duration resulted in a bigger effluent plume depth than in June/July owing to the stronger density gradients in the intermediate and bottom layers in May and September. The results show that sea water quality, in terms of effluent
plume retention below the sea surface, is independent of the bora wind’s influence throughout the summer. Future studies should investigate the advection of the effluent plume in the far-field zone Navitoclax manufacturer and the possibility of upwelling. Other synoptic situations having possible effects on summer vertical stratification should also be studied in more detail (e.g. Lenvatinib mw sirocco wind events). Some new studies are already being carried out along these lines. “
“Electron microscopy remains a prime instrument in phage
ecology studies of most unexplored aquatic ecosystems (Pearce & Wilson 2003, Drucker & Dutova 2006). Morphological investigations of virioplankton range from descriptions of new phages to illustrations of the distribution of biodiversity (Ackermann 2001, Castberg et al. 2002). Despite the advantages of relatively new approaches such as epifluorescence microscopy (Noble & Fuhrman 1998) and flow cytometry (Brussaard et al. 2000), the application of transmission electron microscopy (TEM) in virioplankton studies allows more accurate information about virus morphology and size distribution to be obtained (Børsheim et al. 1990). The taxonomic structuring of phage-like particles has been proposed by several authors (Bradley 1967, Ackermann & Eisenstark 1974, Wichels et al. 1998) Exoribonuclease and approved by the International Committee on Taxonomy of Viruses (ICTV). Studies with the aim of grouping viruses into size classes
have shown that morphological types of viruses are distributed widely in different pelagic ecosystems (Weinbauer 2004). The vast majority of phages belong to the order Caudovirales and have a broad range of isometric heads varying from 20 to 200 nm, with the 30–60 nm size class phages dominant in marine ( Wommack et al. 1992) and 60–90 nm phages prevalent in fluvial and lacustrine ecosystems ( Mathias et al. 1995, Drucker & Dutova 2006). Recent studies, particularly in unexplored aquatic areas, lack morphological analyses of viruses. Molecular analyses and virus genome sequencing are often used in virus research and identification, but genome size can provide only a rough estimate of the rates of ecological interactions between predator and prey, and synergistic or antagonistic relations among predators (grazers and viruses). The same genome size viruses could possibly exhibit different morphological forms. Holmfeldt et al. (2007) showed two different morphological forms with a very similar genome size.