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Thus the surface DMS in the Arabian Sea shows very high spatial and temporal variability. The overall surface DMS average for the Arabian Sea was 6.3 nM. On the other hand, surface DMS concentration in the coastal waters (off the Paradip in the north and Chennai in the south) in the western Bay of Bengal varied from 1.2 to 3.9 nM with an average of 2.6 nM during the SW monsoon, when the central Bay waters contained the surface DMS concentrations of 0.2-11.1 nM...

Does Phaeocystis spp contribute significantly to vertical export of organic carbon

Received 10 April 2006 Accepted 10 August 2006 Published online 23 March 2007 Springer Science+Business Media B.V. 2007 Abstract Phaeocystis spp. cell and colony mass fluxes and their contribution to the vertical particulate organic carbon (POC) export from a wide range of stations were quantified by short-term sediment traps. The compilation of available data, ranging from polar to sub-arctic and boreal regions, revealed that Phaeocystis colonial and single cells frequently are observed in...

S Becquevort C Lancelot V Schoemann

Received 5 May 2006 Accepted 16 November 2006 Published online 24 April 2007 Springer Science+Business Media B.V. 2007 Abstract In high-nutrient low-chlorophyll areas, bacterial degradation of organic matter may be iron-limited. The response of heterotrophic bacteria to Fe addition may be directly controlled by Fe availability and or indirectly controlled through the effect of enhanced phytoplankton productivity and the subsequent supply of organic matter suitable for bacteria. In the present...

Environmental constraints on the production and removal of the climatically active gas dimethylsulphide DMS and

Jacqueline Stefels Michael Steinke Suzanne Turner Gill Malin Sauveur Belviso Received 14 June 2006 Accepted 5 August 2006 Published online 27 April 2007 Springer Science+Business Media B.V. 2007 Abstract Seawater concentrations of the climate-cooling, volatile sulphur compound dimethylsul-phide (DMS) are the result of numerous production and consumption processes within the marine ecosystem. Due to this complex nature, it is difficult to predict temporal and geographical distribution patterns...

Methods used to reveal genetic diversity in the colonyforming prymnesiophytes Phaeocystis antarctica P globosa and P

Hayes Linda K. Medlin Received 12 October 2005 Accepted 17 March 2006 Published online 12 April 2007 Springer Science+Business Media B.V. 2007 Abstract Previous work on the genetic diversity of Phaeocystis used ribosomal DNA and internal transcribed spacer (ITS) sequence analyses to show that there is substantial inter- and intraspe-cific variation within the genus. First attempts to trace the biogeographical history of strains in Antarctic coastal waters were based on a...

Mechanisms of DOM release during a Phaeocystis bloom

In general 10-25 of phytoplankton primary production is released as DOC (Sharp 1977 Larsson and Hagstrom 1979 Lignell 1990 Teira et al. 2003 Maranon et al. 2004). The three main mechanisms of DOM production are (1) release after cell lysis, e.g., as a result of viral infection, zooplankton sloppy feeding and egestion, (2) bacterial cleavage of exopolysaccharides (Smith et al. 1995), or (3) direct release as a physiological process of intact cells (reviewed by Nagata 2000). Two physiological...

Phaeocystis carbohydrates and their characteristics

Carbohydrates in algae and plants are often classified based on methodological discrimination. The structural carbohydrates are not water-soluble, whereas the other types of carbohydrates are water-soluble and typically extracted by hot water. In Phaeocystis five different pools of carbohydrates can be distinguished. Like all algal and plant cells, both solitary and colonial cells produce (1) structural carbohydrates, polysaccha-rides that are mainly part of the cell wall, (2) mono- and...

Phaeocystis and its interaction with viruses

Brussaard Gunnar Bratbak Anne-Claire Baudoux Piet Ruardij Received 10 November 2005 Accepted 14 February 2006 Published online 7 April 2007 Springer Science+Business Media B.V. 2007 Abstract Over the years, viruses have been shown to be mortality agents for a wide range of phytoplankton species, including species within the genus Phaeocystis (Prymnesiophyceae). With its polymorphic life cycle, its worldwide distribution, and the capacity of several of the Phaeocystis species to...

The colonization of two Phaeocystis species Prymnesiophyceae by pennate diatoms and other protists a significant

Felipe Artigas Jens C. Nejstgaard Marc E. Frischer Received 2 October 2005 Accepted 12 June 2006 Published online 14 March 2007 Springer Science+Business Media B.V. 2007 Abstract The association of Phaeocystis spp. with small pennate diatoms during three Phaeo-cystis-dominated spring blooms were investigated in the Eastern English Channel (2003 and 2004) and in coastal waters of Western Norway during a mesocosm experiment (2005). In each of these studies, colonization of the...

Microbial degradation

Dom Microbial Degradation

Generally, most of the biomass produced in Phaeocystis blooms is remineralized in the water column (Wassmann 1994, Rousseau et al. 2000) by heterotrophic bacteria. Occasionally, however, accumulation of DOM and foam have been reported (e.g. Eberlein et al. 1985 Lancelot et al. 1987 Seuront et al., 2007). This seems to indicate that bacterial degradation of organic matter produced by in Phaeocystis blooms varies between blooms, and sometimes is hampered. There may be various reasons for slow...

Variability in abundance and fluxes of dimethyl sulphide in the Indian Ocean

Received 16 February 2006 Accepted 16 November 2006 Published online 8 March 2007 Springer Science+Business Media B.V. 2007 Abstract Dimethyl sulphide (DMS) is a biogenic gas of climatic significance on which limited information is available from the Indian Ocean. To fill this gap, we collected data on DMS and total dimethylsulphoniopropionate (DMSPt) by participating in a dozen cruises. Here, we discuss the variability in DMS and DMSPt in the north and central Indian Ocean in terms of their...

Results and discussion

Shipboard iron-light manipulation experiment The starting seawater collected for this experiment contained high concentrations of dissolved inorganic macronutrients that were typical of surface waters in the Ross Sea during early summer -20 iM nitrate + nitrite, -1.5 iM phosphate, and -55 iM silicic acid. Analysis of iron in 0.4-iM filtered subsamples of the starting seawa-ter using methods described by Sedwick et al. (2005) revealed an initial dissolved Fe concentration of 0.38 0.03 nM (n 2)....

Review Paper

A taxonomic review of the genus Phaeocystis Received 20 October 2005 Accepted 22 August 2006 Published online 15 March 2007 Springer Science+Business Media B.V. 2007 Abstract Phaeocystis is recognized both as a nuisance and as an ecologically important phyto-plankton species. Its polymorphic life cycle with both colonial and flagellated cells causes many taxonomic problems. Sequence variation among 22 isolates representing a global distribution of the genus has been compared using three...

Materials and methods

Regrowth experiments were performed by mixing P. antarctica-derived organic matter with an inoculum of Antarctic bacteria. Phaeocystis-derived organic matter was prepared from pure cultures of P. antarctica grown under Fe-limiting (LFe) and enriched conditions (HFe). All the experimental procedures were carried out under trace-metal clean conditions as described in Schoemann et al. (2001). Except for the organic matter sampling, flasks and filtration devices used for Phaeocystis cultures, the...

Gaining integrated understanding of Phaeocystis spp Prymnesiophyceae through modeldriven laboratory and mesocosm studies

Phaeocystis Pouchetii

Patten Peter G. Verity Marc E. Frischer Jeremy D. Long Jens C. Nejstgaard Jon T. Anderson Anita Jacobsen Aud Larsen Joaquin Martinez-Martinez Stuart R. Borrett Received 20 April 2006 Accepted 7 September 2006 Published online 8 March 2007 Springer Science Business Media B.V. 2007 Abstract Knowledge of the complex life cycle of Phaeocystis is a key to understanding its role in marine ecosystems and global biogeochemistry. An existing life cycle model was modified and...