We investigated the physical conditions of the Spring pack ice environment at Terra Nova Bay to understand their influence on the structure and physiology of sympagic microalgae. Bio-optical methods were used to study the availability and spectral quality of solar radiation, both inside and underneath the ice cover. Pack ice thickness was around 2.5 m, with a temperature between -2 and -7°C. On average, only 1.4% of surface PAR penetrated to the bottom ice and less than 0.6% below platelet ice level. Surface UV-B radiation under the bottom ice was 0.2–0.4%. Biomass concentrations up to 2400 mg Chl a m-3, dominated by two species of diatoms (Entomoneis kjellmannii and Nitschia cf. stellata), showed marked spatial and temporal patterns. Maximum values were in the platelet ice during the first half of November, and in the bottom ice two weeks later. Strong shade adaptation characteristics emerged clearly and explained the relevant abundance of microalgae within the sea ice, with specific absorption coefficients (a*) as low as 0.005 m2 (mg Chl a)-1 and the photo-acclimation index (Ek) in the range of in situ irradiance. The biomass specific production values were low, around 0.12–0.13 mg C mg Chl a-1 h -1. The hypothesis suggesting bottom ice colonization by platelet ice microalgae is supported here.

Light environment and seasonal dynamics of microalgae in the annual sea ice at Terra Nova Bay (Ross Sea, Antarctica) / L. LAZZARA; NARDELLO I; ERMANNI C; MANGONI O.; V. SAGGIOMO. - In: ANTARCTIC SCIENCE. - ISSN 0954-1020. - STAMPA. - 19:(2007), pp. 101-114. [10.1017/S0954102007000119]

Light environment and seasonal dynamics of microalgae in the annual sea ice at Terra Nova Bay (Ross Sea, Antarctica).

L. LAZZARA;
2007

Abstract

We investigated the physical conditions of the Spring pack ice environment at Terra Nova Bay to understand their influence on the structure and physiology of sympagic microalgae. Bio-optical methods were used to study the availability and spectral quality of solar radiation, both inside and underneath the ice cover. Pack ice thickness was around 2.5 m, with a temperature between -2 and -7°C. On average, only 1.4% of surface PAR penetrated to the bottom ice and less than 0.6% below platelet ice level. Surface UV-B radiation under the bottom ice was 0.2–0.4%. Biomass concentrations up to 2400 mg Chl a m-3, dominated by two species of diatoms (Entomoneis kjellmannii and Nitschia cf. stellata), showed marked spatial and temporal patterns. Maximum values were in the platelet ice during the first half of November, and in the bottom ice two weeks later. Strong shade adaptation characteristics emerged clearly and explained the relevant abundance of microalgae within the sea ice, with specific absorption coefficients (a*) as low as 0.005 m2 (mg Chl a)-1 and the photo-acclimation index (Ek) in the range of in situ irradiance. The biomass specific production values were low, around 0.12–0.13 mg C mg Chl a-1 h -1. The hypothesis suggesting bottom ice colonization by platelet ice microalgae is supported here.
2007
19
101
114
L. LAZZARA; NARDELLO I; ERMANNI C; MANGONI O.; V. SAGGIOMO
File in questo prodotto:
File Dimensione Formato  
_Lazzara_etal_AS_07.pdf

accesso aperto

Tipologia: Versione finale referata (Postprint, Accepted manuscript)
Licenza: Open Access
Dimensione 1.24 MB
Formato Adobe PDF
1.24 MB Adobe PDF

I documenti in FLORE sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificatore per citare o creare un link a questa risorsa: https://hdl.handle.net/2158/213525
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 40
  • ???jsp.display-item.citation.isi??? 36
social impact