Carbon fluxes and export in the northern and middle Atlantic Sea measured with drifting sediment traps

Miquel, J-C ; Fowler, S ; Hamilton, T ; Heilmann, J P ; LaRosa, J ; Carroll, M

Lawrence Livermore National Laboratory

关键词: Surface Waters;    Particulates;    Adriatic Sea;    Chlorophyll;    Sediments;   

DOI  :  10.2172/15005963
RP-ID  :  UCRL-JC-140908
RP-ID  :  W-7405-ENG-48
RP-ID  :  15005963

美国|英语

来源: UNT Digital Library

【 摘 要 】

In July 1993 and June 1995 drifting sediment traps were deployed near the Po outflow, in the coastal zone and in the Jabuka Pit in order to obtain quantitative information on the vertical flux of particulate material and export of organic carbon in the Northern and Middle Adriatic Sea. During these periods and in July 1994, the standing stock of carbon and nitrogen in the water column were also estimated. Carbon and nitrogen concentrations were higher in the north with a mean of 266 {micro}g C l{sup -1} in surface waters as compared to 92 {micro}g C l{sup -1} in Middle Adriatic; maximum concentrations were associated to the less-saline surface-subsurface waters in the north and to the chlorophyll a maximum in the Middle Adriatic. Organic carbon flux was roughly five times higher near the Po than in the more oligotrophic waters of the central region, with overall values (0.8 to 11.5 mg m{sup -2} d{sup -1}) being low compared to the open Northwestern Mediterranean. Comparison with primary production measurements yielded estimates of carbon export (f-ratio) of 4.7 and 3.4% in the Po and Pit stations, respectively, in 1993 and of 1.6 and 3.6% in the central part of the Adriatic in 1995. These consistently low values suggest enhanced carbon recycling in the upper water column, even in regions characterized by different production and organic flux regimes. Zooplankton fecal pellets were important conveyors of organic carbon in this region; particularly those produced by fishes in the North and coastal sites.