Open AccessSatellite captures trichodesmium blooms in the southwestern tropical Pacific
Author(s) -
Dupouy Cécile,
Neveux Jacques,
Subramaniam Ajit,
Mulholland Margaret R.,
Montoya Joseph P.,
Campbell Lisa,
Carpenter Edward J.,
Capone Douglas G.
Publication year - 2000
Publication title -
eos, transactions american geophysical union
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.316
H-Index - 86
eISSN - 2324-9250
pISSN - 0096-3941
DOI - 10.1029/00eo00008
Subject(s) - trichodesmium , seawifs , oceanography , cyanobacteria , environmental science , photic zone , oscillatoria , nitrogen fixation , phytoplankton , nitrogen , diazotroph , geology , biology , ecology , chemistry , nutrient , paleontology , organic chemistry , bacteria
Obtaining a true estimate of nitrogen fixation by cyanobacteria in the oceans, mainly Trichodesmium , is an important step toward understanding the entire nitrogen cycle in the tropical ocean. This strictly anaerobic process, which has a high Fe requirement, could regulate atmospheric CO 2 over geological time. For example, during interglacial periods, N 2 fixation would be too low (low Fe) to balance denitrification and the ocean would lose its fixed nitrogen [ Falkowski , 1997]. Has the level of marine nitrogen fixation been underestimated until now? High N 2 fixation rates measured on Trichodesmium spp. communities have led to an upward revision of this marine flux [ Capone et al , 1997]. Recent modeling studies and observations predict that N 2 fixation could regulate the long‐term N:P equilibrium in the oceans and balance denitrification [ Tyrell , 1999; J L. Sarmiento and N. Gruber , manuscript in preparation, 1999].The major nitrogen fixer, Trichodesmium spp., which are filamentous, nonheterocystous N 2 ‐fixing cyanobacteria, has a nearly ubiquitous distribution in the euphotic zone of tropical and subtropical seas and could play a major role in bringing new N to these oligotrophic systems. Satellite images from Sea‐viewing Wide Field‐of‐view Sensor (SeaWiFs), the recently launched ocean color sensor, and data from a recent cruise, provide further evidence of the importance of Trichodesmium in the southwestern tropical Pacific Ocean.