Original scientific paper

Distribution of Carbohydrates during a Diatom Bloom in the Northern Adriatic

Senka Terzić ; Center for Marine and Environmental Research, Ruđer Bošković Institut, P.O.B. 1016, HR-10001 Zagreb, Croatia
Marijan Ahel ; Center for Marine and Environmental Research, Ruđer Bošković Institut, P.O.B. 1016, HR-10001 Zagreb, Croatia

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 α 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 μg C/l to 1300 μg 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).

Keywords

Hrčak ID:

132345

URI

https://hrcak.srce.hr/132345

Publication date:

4.5.1998.

Visits: 664 *