Distribution of carbohydrates during a diatom bloom in the northern Adriatic

Terzić, Senka; Ahel, Marijan (1998) Distribution of carbohydrates during a diatom bloom in the northern Adriatic. Croatica Chemica Acta, 71 (2). pp. 245-262. ISSN 0011-1643

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Abstract

Distribution of carbohydrates was studied in the northern Adriatic during an autumn phytoplankton bloom triggered by strong freshwater discharges from the Po River at the end of the stratification period in October 1993. Total carbohydrates (TCHO) and monosaccharides (MCHO) were determined spectrophotometrically using the MBTH-method, while phytoplankton biomass was followed by determining chlorophyll and carotenoid pigments using the HPLC technique. As indicated by the concomitant increase of chlorophyll a and fucoxanthin, an intensive diatom bloom developed in the upper 5 m of the water column while the chlorophyll biomass was rather low in the layers below 10 m. Total carbohydrate levels varied from 70 mu g C/l to 1300 mu g C/l with significantly enhanced values in the top 5 m of the water column suggesting a strong link to the diatom biomass. However, it was shown that not only the diatom crop but also the physiological status of the biomass, as reflected by the chlorophyll break-down products, had a strong impact on the TCHO levels. Carbohydrates were found mainly in the form of polysaccharides (up to 92% of TCHO).

Item Type:

Article

Uncontrolled Keywords:

n-p ratio; organic-matter; spring bloom; phytoplankton; sea; particulate; seawater; pigment; growth; algae

Subjects:

NATURAL SCIENCES > Chemistry

Divisions:

Division for Marine and Enviromental Research

Projects: