Diatom quantification and their distribution with salinity brines in coastal sediments of terra nova bay (antarctica)

Franco Baldi (1) , Chiara Facca (1) , Davide Marchetto (1) , Thi Nhu Mai Nguyen (2) , Roberto Spurio (2)

1 Department of Environmental Sciences
2 University of Camerino

Benthic diatoms represent an important element of global nutritional productivity; to raise attention on their role, which is often neglected due to analytical difficulties, surface (1 cm top layer) coastal sediments from Gerlache inlet to Penguin Bay at Terra Nova Bay were collected and stored at -20°C. DNA amplification by real-time-PCR, based on diatom-specific oligonucleotide primers designed on small-subunit rRNA (SSU rRNA), was performed in addition to diatom conventional cell counting and spectrophotometric determination of photo-pigments. Moreover, cations and anions were determined in sediments with the aim to identify factors involved in the control of diatom abundance. Diatom distribution was found quite heterogeneous displaying significant differences from site to site. The salinity in sediments ranged from 45.1 at Gerlache inlet to 76.2 at Penguin Bay and it was correlated with cell abundance, biodiversity, amount of pigments and amplified DNA. The dominant species, , was associated to sediment salinity brines.

Mots clés: diatoms; real-time PCR; coastal sediments; SEM-EDX analyses; salinity brines; Terra Nova Bay

Domaines: Sciences du Vivant [q-bio]

Franco Baldi, Chiara Facca, Davide Marchetto, Thi Nhu Mai Nguyen, Roberto Spurio. Diatom quantification and their distribution with salinity brines in coastal sediments of terra nova bay (antarctica). Marine Environmental Research, 2011, 71 (4), pp.304. ⟨10.1016/j.marenvres.2011.02.005⟩. ⟨hal-00682418⟩