Regional Report for PICES Region 20, 54 pp.

Annual variation in NO3-N, DIN (the inset in figure A), NH4-N (DIN), PO4-P, SiO3-Si, the N/P ratio, and DO concentrations in the SYS from the 1980s to 2012 (Note: The data represent average values ± the standard deviation during different years in the study area; in figures A and B, the filled and open circles stand for the field and computational data, respectively) (Li et al. [...] (2015), the variations of the nutrient concentrations in the southern Yellow Sea were related to the variations of the riverine flux and atmospheric deposition, and especially the long-term variations of SiO3-Si and PO4-P concentrations were both generally consistent with the variation of precipitation (Wei et al. [...] In addition, the nutrient transport by the inflow from the outer shelf of the East China Sea, in combination with the anthropogenic eutrophication in the coastal zones, may also influence the nutrient levels in the southern Yellow Sea under the global change. [...] These studies provided additional examples of the increase in the concentrations of PO4-P and SiO3-Si and the continuous increase in the concentration of DIN in the Yellow Sea since the late 1990s. [...] (2013) also attributed the increase in the intensity of the phytoplankton blooms to the increase in the concentrations of NO3-N and PO4-P in the Yellow Sea.