Low water column nitrogen fixation in the Mediterranean Sea: basin-wide experimental evidence

Aquatic Microbial Ecology

Susana Agustí¹  Lucas J. Stal¹  Nona S. R. Agawin¹  Marta Alvarez¹  Carlos M. Duarte¹  Antonio Tovar-Sanchez¹ 

关键词: Nitrogen fixation;    Trichodesmium sp.;    Mediterranean Sea;   

DOI  :  10.3354/ame01511

学科分类：生物科学（综合）

来源: Inter-Research

【 摘 要 】

ABSTRACT: The abundance and nitrogen fixation rates of Trichodesmium sp. integrated down to the deep chlorophyll maximum as well as nitrogen fixation rates in size-fractionated discrete surface water samples were measured across the Mediterranean Sea. The abundance of Trichodesmium sp. was generally low (<50 trichomes m^�?3), except at one station in the Tyrrhenian Sea where the water temperature was >20°C and Trichodesmium sp. was present at a higher density (ca. 700 trichomes m^�?3). Across the basin, size-fractionated nitrogen fixation rates were low (<250 nmol N₂ m^�?3 h^�?1). The highest rate was measured at a station characterized by relatively high concentrations of total ­dissolved P and dissolved Fe. High δ¹⁵N values (8.04 ± 2.03�?) of the particulate organic nitrogen were in accordance with the observed low water column nitrogen fixation rates across the Mediterranean Sea.

【 授权许可】

Unknown