engleski

Pigment distribution during a mucilage event in the Adriatic

The occasional extensive appearance of mucus aggregatesnin the summer period is specific to the northern Adriatic. We followed this phenomenon from July to September 1997 focusing on temporal changes of phytoplankton in mucous aggregates as reflected by biomarker pigments. The largest percentage of the autotrophic biomass in all samples was associated with fucoxanthin-containing phytoplankton (21-144 microg/g dry mucilage) which contributed 41-75 percent of the total biomass. Contribution of other individual biomarkers was generally less than 15 percent, except for peridinin-containing species, which reached nearly 40 percent in August. These results suggest that microplankton, especially diatoms, play a key role in the development and maintenance of mucilage. The composition of phytoplankton biomass in the surrounding waters was markedly different. In the surface layer (less of 10m) the unusual prevalence of fucoxanthin-containing biomass in July was followed by a more typical system dominated by pico-/nanoplankton in August. In contast, the lower laxer (more than 10m) was strongly dominated by microplankton (fucoxanthin and peridinin) troughout the summer. These data indicate a temporary decoupling of phytoplankton dynamics in mucilage and surrounding water

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nije evidentirano