|
|
|
|
|
| Maestrini, Serge; Balode, Maija; Bechemin, Christian; Purina, Ingrida; Verite, Celine. |
| In May, June and July 1996, samples wcre collected along one transect greatly influenced by river discharge (eastern side of the gulf), along one transect slightly influence by river discharge (western side), at one station Iocated in the mouth of the main river (River Daugava), at one station located in the center of the Gulf and at several nearshore locations of the western side. Ratios of rnolecular concentrations of in situ dissolved ioorganic nitrogen, phosphorus and silicon, as weIl as enrichment bioassays were llsed to dctcrrnine which nutrient (s) lirnited the potential biomass of phytoplankton. Both comparison of (NO.d-N02+NJ.L): P04 (DIN: DIP) values with Redfic1d's ratio and bioassay inspection led to the sarne conclusions. Phosphorus was... |
| Tipo: Text |
|
| Ano: 1997 |
URL: http://archimer.ifremer.fr/doc/00353/46409/46135.pdf |
| |
|
| |
|
|
| Maestrini, Serge; Balode, Maija; Bechemin, Christian; Purina, Ingrida. |
| To investigate whether uptake of dissolved organic compounds might favour the growth potential of toxic cyanobacteria and dinoflagellates, surface water was collected in late July 1997 in the Gulf of Riga, and enriched with different nitrogen sources. (1) Organic substances were added (25 mu M N) under P-, Si- and Fe-replete conditions. Urea sustained a biomass increase (protein content) 20% greater than that with NH sub(4) super(+). Glycine, hypoxanthine and putrescine gave only 50% of the biomass obtained with NH sub(4) super(+). Glutamic acid and spermine supported growth in only one case each, and guanine in none. (2) The >1000 dalton fraction of dissolved organic matter (DOM) taken from the Daugava River was provided at concentrations of 5, 15 and... |
| Tipo: Text |
Palavras-chave: Phytoplankton; Terrigenous DON; Nitrogenous nutrients; Baltic Sea. |
| Ano: 1999 |
URL: http://archimer.ifremer.fr/doc/00173/28437/26769.pdf |
| |
|
|
| Stolte, Willem; Balode, Maija; Carlsson, Per; Grzebyk, Daniel; Janson, Sven; Lips, Inga; Panosso, Renata; Ward, Clive J.; Graneli, Edna. |
| In the Baltic Sea, floating blooms of nitrogen-fixing cyanobacteria occur yearly during late summer. These blooms can sometimes be limited by iron. Due to extensive foresting around the Baltic Sea, iron is entering the Baltic Sea partly bound to dissolved organic material (DOM) via rivers. An experiment was performed in 300 1 laboratory mesocosms to test the hypothesis that riverine high-molecular weight dissolved organic matter (HMWDOM), extracted by tangential flow filtration > 1000 Da, stimulates the biomass of nitrogen-fixing cyanobacteria, by increasing the availability of iron. The addition of iron/EDTA and of DOM resulted in 5 to 10 times higher biomass of nitrogen-fixing cyanobacteria. Accordingly, higher primary production and particulate... |
| Tipo: Text |
Palavras-chave: Mesocosm experiment; Humic acid; HMWDOM; High molecular weight dissolved organic matter; Iron; Nitrogen fixation; Cyanobacteria. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-2470.pdf |
| |
|
|
|
