H. Kawahata et al., SEASONAL AND VERTICAL VARIATIONS OF SINKING PARTICLE FLUXES IN THE WEST CAROLINE BASIN, Oceanologica acta, 21(4), 1998, pp. 521-532
A sediment trap experiment was carried out in the West Caroline Basin,
located in the equatorial western Pacific between influences of the A
sian monsoon and the open ocean. Annual mass flux at the shallow trap
at Site 1 was 57.10 g m(-2)yr(-1). Generally, the higher flux of organ
ic matter was associated with higher activities of biogenic opal-produ
cing and carbonate-producing plankton communities. In addition, as the
organic matter content increases, the organic carbon/carbonate carbon
ratio shows a tendency to increase. Carbonate-producing plankton was
predominant during periods 1 and 3 (May to July and November to the be
ginning of December), which could be due to limited silica supply to t
he euphotic zone. On the other hand, surface sea water was more nutrie
nt-rich during periods 2 and 4 (August to October and the end of Decem
ber to April) at Site 1. These high total mass fluxes could be stimula
ted by wind. The amount of biogenic components collected in the sedime
nt traps and the accumulation in surface sediments at Site 1 could be
compared with primary productivity values. Carbonate and biogenic opal
fluxes were 99 % and 90 % less, respectively, in the surface sediment
s compared to those in the shallow sediment trap. This could be due to
the reaction of sinking particles with undersaturated deep sea water
just above the sea floor, rather than with the water column during sin
king. About 20 % of the organic matter was decomposed between the shal
low and deep sediment traps and more than 98 % between the deep sedime
nt trap and final burial in the surface sediments. The relative amount
of organic carbon preserved in surface sediments was about 0.10 % of
annual primary productivity. (C) Elsevier, Paris.