Riverine inputs of nutrients

The total atmospheric fluxes to the southern YS are respectively calculated based on the results as we discussed above. In order to account for the importance of air to sea fluxes in the area, the values are compared with the riverine inputs (Table 3.11, Wan et al., 2003). The Changjiang River flows into the southern YS in a different ratio for each season. Based on the drainage areas and concentrations of nutrients, the riverine inputs of nutrient elements to the YS can be obtained. 

Table 3.11. The comparison between annual atmospheric and riverine inputs of nutrient elements to the SYS and the ECS (xlO g/yr) (Wan et al., 2003) (With permission from Wan XF)...

Inputs of nutrient N and P to the coastal zone which support new primary production are from the land by riverine and groundwater flows, from the open ocean by coastal upwelling and onwelling, and to a lesser extent by atmospheric deposition of nitrogen. New primary production depends on the... 

Morton B, Blackmore G (2001) South China Sea. Mar PoUut Bull 42(12) 1236-1263 Muscatine L, Porter JW (1977) Reef corals Mutualistic symbioses adapted to nutrient-poor environments. Bioscience 27(7) 454-460 Ni HG, Lu FH, Luo XL, Tian HY, Zeng EY (2008) Riverine inputs of total organic carbon and suspended particulate matter from the Pearl River delta to the coastal ocean off South China. Mar PoUut Bull 56(6) 1150-1157 Onstad GD, Canfield DE, Quay PD, Hedges JI (2000) Sources of particulate organic matter in rivers from the continental USA Lignin phenol and stable carbon isotope compositions. Geochim Cosmochim Acta 64(20) 3539-3546 Peng Z, Chen T, Nei B, Head MJ, He X, Zhou W (2003) Coral records as an indicator of winter monsoon intensity in the South China Sea. Quat Res 59(3) 285-292... 

The majority of runoff from land to the oceans is dominated by riverine inputs, with minimal inputs directly from groundwater runoff. However, recent work has shown that SGD into estuaries and coastal waters is more significant than previously thought and may have significant impacts on the cycling of nutrients and contaminants. 

In RiOMar environments, the input of vascular plant-derived organic matter from land is significant, and marine primary productivity is high due to high nutrient inputs associated with riverine discharge. 

Given the importance of riverine input to Si cycling in the oceans, any changes in the source or nutrient ratios could have an impact on diatom production and... 

In the preceding sections we showed that riverine nutrient inputs impact regional seas. We also stated in Section 6.5.4 that the huge reservoirs of nutrients in the deep ocean mean that increases in, for example, the concentrations of NOf in riverwaters due to human activity have little effect on oceanic NO, concentration, assuming that NOf is effectively mixed throughout the ocean volume. We can now demonstrate that this is the case using some simple reasoning. 

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