부산대학교 도서관

Although the importance of phytoplankton in the Arctic Ocean has been emphasized, few studies on the primary production of phytoplankton are reported in the Kara Sea (KS), the Laptev Sea (LS), and the East Siberian Sea (ESS). During the three NABOS expeditions carried out in 2013, 2015, and 2018, in-situ carbon uptake rates were measured using a 13C-15N dual-tracer method, and their controlling environmental factors were examined in the KS, the LS, and the ESS to determine current primary production of phytoplankton. The carbon uptake rates in this study (99 ± 62, 100 ± 77, and 56 ± 35 mg m-2 d-1 in the KS, the LS, and the ESS, respectively) are different from the values previously reported in each sea mainly because of spatial and regional differences. Among the three seas, large regional differences were observed in the carbon uptake rates, with an approximately 2 times higher rate in the KS and the LS in comparison to that in the ESS. This was mostly caused by a regional difference in freshwater content based on the noticeable relationship (rs = - 0.714, p < 0.05) between freshwater content and carbon uptake rates. The underlying mechanism for that freshwater content could cause the strong stratification (rs = 0.720, p < 0.01) and subsequently lower uptake inputs of nitrite + nitrate concentrations (rs = - 0.450, p < 0.01) during our study period. From this study, we also confirmed the negative effect of the freshwater content on the primary production of phytoplankton in the KS, the LS, and the ESS. The ranges of carbon uptake rates based on this, and previous studies were 8-220 mg m-2 d-1, 6-421 mg m-2 d-1, and 14-139 mg m-2 d-1 in the KS, the LS, and the ESS, respectively.