Exhaustion of nitrate terminates a phytoplankton bloom in Funka Bay, Japan:change in SiO4:NO3 consumption rate during the bloom

Autor:	Isao Kudo, Katsuhiko Matsunaga, Mitsuru Yanada, Takeshi Yoshimura
Rok vydání:	2000
Předmět:	Ecology biology Chaetoceros Aquatic Science Spring bloom Nitrate reductase biology.organism_classification Algal bloom chemistry.chemical_compound Oceanography Nitrate chemistry Environmental chemistry Phytoplankton Photic zone Bloom Ecology Evolution Behavior and Systematics
Zdroj:	Marine Ecology Progress Series. 193:45-51
ISSN:	1616-1599 0171-8630
Popis:	Time series observations over 36 h were carried out in Funka Bay, Japan, to complement a 6 yr nutrient-dynamics study during a diatom spring bloom, especially focusing on nitrate and silicate as limiting nutrients. At the beginning of the study, nutrient concentrations were high (NO 3 = 10 μM, SiO 4 = 20 μM and PO 4 = 0.8 μM). Nitrate was depleted first during the night while silicate and phosphate remained at 10 and 0.3 μM, respectively. High nitrate reductase activity was observed the following morning, indicating the assimilation of nitrate in situ by the dominant phytoplankter, Chaetoceros socialis. The consumption ratio of SiO 4 :NO 3 increased by 3 times from 0.83 before the peak to 2.5 after the peak of the bloom. This change was also obvious in the elemental composition of phytoplankton, showing an increase in Si:C and Si:N ratios by a factor of 2 to 4 after the peak of the bloom, while C:N ratio remained constant at around 7. As a consequence of this change in the consumption rate of SiO 4 and NO 3 , both silicate and nitrate were finally depleted in the photic zone.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::497026b918cf78e68eb758a1216b9d64 https://doi.org/10.3354/meps193045 Zobrazit plný text záznamu