Articolo in rivista, 2009,

Photoacclimation in Antarctic bottom ice algae: an experimental approach

Mangoni O. (1), Carrada G.C. (1), Modigh M. (2), Catalano G. (3) , Saggiamo 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, Trieste, Italy

The aim of the study was to investigate the capacity of microalgae from the extremely low light habitat of bottom ice to acclimate to different light conditions. During austral spring 1997 the bottom layer of land-fast ice in Terra Nova Bay displayed high values of microalgal biomass concentrated in a few centimetres ice layer. The algal assemblage was dominated by benthic pennate diatoms. Photoacclimation of the microalgae was addressed in terms of pigment spectra and photosynthetic parameters. Immediate and long term (minutes to days) changes in the photoprotective pigments (DD-cycle) were analysed. Severe photodamage occurred in microalgal assemblages exposed to high light. However, part of the bottom ice algal community showed a notable ability to acclimate to high irradiance levels. Changes in photosynthetic parameters preceded the sudden abrupt changes in pigment synthesis and the rapid increase in biomass and growth rates.

Polar biology (Print) 32 , pp. 325–335

Keywords

Ross Sea, Terra Nova Bay, fast ice, bottom ice, microalgae

CNR authors

Catalano Giulio

CNR institutes

ISMAR – Istituto di scienze marine