The Relationship of Bioturbation, Macrobenthos and Seabed Radionuclides to the Flux and Fate of Organic Carbon Along the JGOFS Equatorial Pacific Transect

1991-1992年，美国JGOFS赤道太平洋计划将研究140oW赤道横断面上有机碳的产生、通量和去向。从赤道向北，这条横断面穿过颗粒有机碳通量的陡峭梯度，埋藏在深海海底。为了阐明有机碳在这些沉积物中的命运，了解生物扰动和海底颗粒动力学(通过自然产生的放射性核素追踪)是必不可少的。S建议沿着这一碳通量梯度检验四个具有生物化学意义的假说：(1)生物扰动速率和深度随每年进入海底的颗粒有机碳(POC)通量而变化，(2)这些变化对有机碳在海底的矿化和埋藏有重大影响，(3)大型底栖动物现存量和平均个体大小与年POC通量相关；(4)在100天、10年和100年尺度上，过量234、228和210铅的海底库存量分别与POC通量相关。

In 1991-1992, the US JGOFS Equatorial Pacific program will study the production, flux and fate of organic carbon along a cross-equatorial transect at 140oW. From the equator northward, this transect traverses a steep gradient in particulate organic-carbon flux and burial at the abyssal seafloor. In order to elucidate the fate of organic carbon in these sediments, an understanding of bioturbation and seabed particle dynamics (as traced by naturally occurring radionuclides) is essential. The P.I.'s propose to test, along this carbon-flux gradient, four hypotheses of biogoechemical significance: (1) bioturbation rates and depths vary with annual particulate organic-carbon (POC) flux to the seafloor, (2) these variations have a significant impact on the mineralization and burial of organic carbon in the seabed, (3) macrobenthic standing crop and mean body size are correlated with annual POC flux, and (4) seabed inventories of excess 234Th, 228Th and 210Pb are correlated with POC flux on 100-d, 10-yr and 100-yr time scales, respectively.