Nitrogen (N) assimilation and regeneration in hypoxic water column of Jinhae Bay, South Korea

Monday, 14 December 2015
Poster Hall (Moscone South)
Seonyoung Park1, Soonmo An1, Jiyoung Lee2, Sohyun Park1, Yunji Kim1 and Jehee Ryu3, (1)Pusan National University, Busan, South Korea, (2)Pusan national university, Busan, South Korea, (3)Busan National Unviversity, Busan, South Korea
Nitrogen generally controls the phytoplankton productivity in marine environment and detailed information regarding N cycling is necessary to understand extreme ecological processes such as hypoxic condition. Generally, primary production was measured using oxygen evolution or stable 13C isotope tracer experiment and nitrogen assimilation rate were estimated assuming certain carbon to nitrogen ratio. The regeneration of N is also estimated from the respiration rates although direct measurement method was applied in some experiments. We measured both photosynthetic and respiration rate using carbon and oxygen based methods, and at the same time, independent experiments for nitrogen assimilation and regeneration process measurement were conducted using stable isotope tracers. The differences of N assimilation and regeneration results between each method were analyzed in the context of hypoxic condition development.