Biological control of dimethylsulfoniopropionate and dimethylsulfide production in the Southern Ocean
Year: 2005
Type: dissertation
Abstract: In order to understand how biota controls the DMS dynamics, especially the DMS production, in the Southern Ocean, five cruises were conducted during 2002 -2004 austral summer.In addition, two incubation experiments were conducted in both ship and laboratory.From the observations during cruises two properties of distributions were found.Those properties are (1) there were discrepancies between peak positions of particulate dimethylsulfoniopropionate (DMSP p ) and chl a concentrations, and (2) DMS concentrations were high in the coastal regions of Antarctica in January 2002.From the shipboard incubation experiments, it was observed that Antarctic krill, Euphausia superba, produced DMS and dissolved dimethylsulfoniopropionate (DMSP d ) in its grazing processes.Copepods also produce DMS, and the potential production rates of DMS in the Southern Ocean by krill and copepods are estimated to be approximately 21 µmol m -2 d -1 and 0.6 µmol m -2 d -1 , respectively.From the phytoplankton incubation experiments, it was observed that the DMSP p : chl a ratio of phytoplankton changed during their growth cycles.The ratios increased as much as 6.5 times during the stationary phase, when chl a remained constant.From findings through these two incubation experiments, observed properties of distributions in the ocean could be partly explained.High DMS production rates of zooplankton and the presence of phytoplankton, which have high DMSP contents in their cells, might facilitate in situ DMS production in the Southern Ocean.It was found that the biological control of DMS concentrations in the Southern Ocean is operated through the whole pelagic food web.
Author: 伸江 笠松
Language: English
Subfield: Oceanography
Field: Earth and Planetary Sciences
Domain: Physical Sciences
SDG: Life below water
Open Access status: green
OpenAlex ID: W645595552