東京湾におけるリンとケイ素の沈降粒子束と循環 Particulate fluxes of phosphate and silicate and their cycles in Tokyo Bay
Sediment traps were deployed at two stations for 4 days from June 12 to 16, 1983, in Tokyo Bay. Settling particles and sediment core samples were analyzed for chemical elements. P fluxes and biogenic silicate fluxes were 3.6-24mg/m<sup>2</sup> day and 0.2-2.8g/m<sup>2</sup> day, respectively. The P/biogenic silicate ratios of settling particles from the 5m layer above the sediment were half of those from the upper layer, and were nearly equal to those of surface sediments. These suggest that P was rapidly regenerated in the water column. The fluxes of P and biogenic silicate observed with sediment traps are normalized to that of Al by asssuming that the acutual flux of Al is equal to the accumulation rates onto the sediment surface. Vertical changes of the normalized flux of each chemical component indicate that more than 90% of P in settling particles is regenerated, while about 70% of biogenic silicate in the settling particles is regenerated in the water column. Regenerated P and silicate flow from Tokyo Bay by exchange of the bay water. The incorporation of chemical components into the particulate phase and the sinking of particles do not mean their final loss from the water column in Tokyo Bay.
地球化学 28(1), 15-20, 1994