[Nutrients in sediment pore water in tidal flat area in Yalujiang Estuary].

The concentrations of NO3-, PO(4)3- and SiO(3)2- in sediment pore waters from tidal flat area in Yalujiang Estuary were determined. The concentration of NO3- in sediment pore waters was almost stable, the average NO3- was 3.0 mumol/L. The concentration of PO(4)3- and SiO(3)2- were 0.8-70.4 mumol/L and 111.6-1054.3 mumol/L, respectively. The depth distribution of PO(4)3- and SiO(3)2- increased with depth at first and then decreased further down. The content of S2- in sediment raise with depth. Under the depth of 13 cm, Eh decreased into minus. pH did not obviously change with depth. The diffusion of nutrients in tidal flat area in Yalujiang estuary was from pore water into overlying water.