Title Page
Abstract
Contents
1. Introduction 14
2. Materials and methods 18
2.1. Study site and sampling 18
2.2. Chemical analysis 21
2.3. Basic optimum multi-parameter (OMP) analysis 24
3. Results 27
3.1. Water masses 27
3.2. Dissolved inorganic nutrients 30
3.3. Dissolved organic nutrients 33
3.4. Contents of water masses by OMP in summer 35
4. Discussion 40
4.1. Cycling of inorganic nutrients 40
4.2. Seasonal distributions of dissolved organic nutrients 44
4.3. Seasonal distributions of stoichiometry in organic matter 46
4.4. Relative contributions from water masses and organic matter decomposition in summer 50
5. Conclusions 56
6. References 58
Table 1. End-member characteristics of water masses and their uncertainties 26
Table 2. Fractions of water masses at each station in the bottom layer 39
Figure 1. Map of sampling stations, bottom topography, and surface currents of the Yellow Sea and East China Sea during the sampling period. The solid and... 20
Figure 2. Horizontal distributions of temperature and salinity in surface seawater of the Yellow Sea and East China Sea during the sampling period (a, e : winter; b, f : spring; c, g : summer; d, h : autumn). 29
Figure 3. Vertical profiles of nutrient concentrations (DIN, DON, DIP, and DOP) in seawater of the Yellow Sea and East China Sea during the sampling period (a, e: winter; b, f: spring; c, g: summer; d, h: autumn). DIN: dissolved inorganic... 32
Figure 4. Horizontal distributions of dissolved inorganic and organic nutrients, and dissolved organic carbon in surface seawater of the Yellow Sea and East China Sea during... 34
Figure 5. Plot of mass balance residuals calculated by OMP (Optimum multi- parameter) analysis versus density. 36
Figure 6. Source water fractions in the bottom layer of the Yellow Sea and East China Sea (a: Changjiang Diluted Water; b: Kuroshio Water c: Yellow Sea Cold... 38
Figure 7. Plots of apparent oxygen utilization (AOU) versus (a) dissolved inorganic nitrogen (DIN) and (b) dissolved inorganic phosphorus (DIP) in... 42
Figure 8. Vertical profile of seasonal dissolved inorganic nitrogen (DIN): dissolved inorganic phosphorus (DIP) ratios in seawater of the Yellow Sea and... 43
Figure 9. Vertical profile of seasonal dissolved organic carbon (DOC): dissolved organic nitrogen (DON) ratios in seawater of the Yellow Sea and East China Sea... 49
Figure 10. Plots of apparent oxygen utilization (AOU) versus (a) △N and (b) △P in seawater of the Yellow Sea and East China Sea during the sampling period.... 54
Figure 11. Fractions of relative contributions from water masses and △X (a: △N; b: △P) of the Yellow Sea and East China Sea during the sampling period.... 55