Dissolved organic carbon production by microbial populations

• Main Authors: Eva Teira, Pablo Serret
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2001
• Subjects: North Atlantic
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.526.8767; http://www.aslo.org/lo/toc/vol_46/issue_6/1370.pdf

Dissolved organic carbon (DOC) production by microbial populations was measured at 19 stations in the Atlantic Ocean to quantify the fraction of photoassimilated carbon that flows through the dissolved organic pool at basin scale and to assess the relationship between the percentage of DOC production, phytoplankton size structure, and rates of net community production. Experiments were conducted during four cruises carried out between May 1998 and October 1999, covering three upwelling regions: Benguela (SW Africa), Mauritania (NW Africa) and NW Spain, and the oligotrophic North Atlantic subtropical gyre between 308N and 368N. Photic zone integrated partic-ulate organic carbon (POC) production rates ranged from 10 to 1,178 mg C m22 h21, thus covering a wide produc-tivity spectrum. The percentage of DOC production with respect to total integrated primary production ranged from 4 to 42%, being larger in oligotrophic, picoplankton-dominated waters, where a balanced metabolism of the micro-bial community was observed, than in productive, net autotrophic waters, where large-sized cells formed the bulk of the phytoplankton biomass. A highly significant relationship was calculated between DOC and POC production rates in upwelling conditions. By contrast, the relationship between these variables in oligotrophic environments was weak, which suggests that different processes could be controlling the release of dissolved organic matter in productive and unproductive waters.