CNR ExploRA

Articolo in rivista, 2009,

The role of platelet ice microalgae in seeding phytoplankton blooms in Terra Nova Bay (Ross Sea, Antarctica): a mesocosm experiment

Mangoni O. (1), Saggiomo M. (2), Modigh M. (2), Catalano G. (3), Zingone A. (2), Saggiomo V. (2)

(1) Dipartimento delle Scienze Biologiche, Università di Napoli Federico II, Via Mezzocannone 8, 80134 Naples, Italy (2) Stazione Zoologica Anton Dohrn, Villa Comunale I, 80121 Naples, Italy (3) CNR, Istituto di Scienze Marine, Viale Romolo Gessi 2, 34123 Trieste, Italy

The aim of this study was to assess the role of platelet ice microalgal communities in seeding pelagic blooms. Nutrient dynamics, microalgal biomass, photosynthetic parameters, cell densities and species succession were studied in two mesocosm experiments, designed to simulate the transition of microalgal communities from platelet ice habitat to pelagic conditions. The microalgal assemblages were dominated by diatoms, 70% of which were benthic species such as Amphiprora kufferathii, Nitzschia stellata, and Berkeleya adeliensis. Photoacclimation of benthic species was inadequate also at relatively low irradiances. Exceptional growth capacity at different light levels was observed for pelagic species such as Fragilariopsis cylindrus and Chaetoceros spp. which may be important in seeding blooms at ice breakup. Fragilariopsis cylindrus showed high growth rates both at 65 and 10% of incident light and in nutrient replete as well as in nutrient depleted conditions. Five days after inoculation, phytoplankton biomass increased and nutrient concentrations decreased in both light conditions.

Polar biology (Print) 32 , pp. 311–323