Dissolved and particulate organic carbon in the Sea of Okhotsk: their transport from continental shelf to ocean interior

• Main Authors: Takeshi Nakatsuka, Mari Toda, Kimitaka Kawamura, Masaaki Wakatsuchi
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Okhotsk; Sakhalin
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.660.8111; http://environ.lowtem.hokudai.ac.jp/saishin.pdf/nakatsuka2004jgr2.pdf

[1] Dissolved and particulate organic carbon (DOC and POC) were measured in water columns of the Sea of Okhotsk together with other hydrological and chemical properties, including phytoplankton pigments (Chl-a) and stable carbon isotopic ratios (d13C) of POC. Transects from shelf to slope off the northeast coast of Sakhalin showed the existence of a cold-water mass in the intermediate layer on the slope area having a density of 26.7–27.0 sq, which is equivalent to the cold and dense water on the shelf (dense shelf water: DSW). The cold intermediate water mass was rich in DOC, POC, and Chl-a, and the d13C of POC was high, similar to that in DSW, indicating that the organic matter in the cold intermediate water is exported from the highly productive shelf area by the outflow of DSW. On the other hand, surface waters near the coast of northern Sakhalin had a very low salinity, which must be affected by the fresh water discharge from the Amur River. The low-salinity water contained a large amount of DOC that was more than 3 times greater than the pelagic surface waters. The linear regression line between the salinity and the DOC in the surface layer of the studied area indicates that the Amur River water contains approximately 690 mM of DOC, and the input of DOC from the Amur to