Long-term interaction between dynamics of marine organic pools and earth's surface bioelemental cycles

为了更好地了解海洋有机质库的动态，在2006财政年度对海洋腐殖质样物质和溶解脂质及溶解有机碳（DOC）的^<14>C的荧光强度进行了测量。结果总结如下：选择荧光溶解有机物（FDOM）作为DOM的主要组成成分，在数量上具有代表性，但在质量上是色谱不可表征的成分，并明确了荧光强度的盆地尺度分布。荧光强度最低的总是地表水，并且随着深度的增加而增加。FDOM的分布与表观氧利用（AOU）相似，在中深海和深海中呈正相关，表明FDOM是由有机物的生物降解就地产生的，具有~ 900年的生物难降解性，FDOM的产生速率与河流输入的DOC和有机碳对沉积物的掩埋速率相当。伊色湾最内层站5 m处溶解脂质和DOC浓度分别为72.32±2.01 pMC（2600年BP）、93.48±2.03 pMC(540年BP)，相上湾口站5 m处溶解脂质和DOC浓度分别为41.31±1.64 pMC（7100年BP）和95.25±2.09 pMC（390年BP）。有趣的是，^<14>C的脂质浓度普遍低于DOC，这表明溶解脂质和大块溶解有机质的动力学存在差异。

The measurements of fluorescent intensity derived from marine humic-like materials and ^<14>C of dissolved lipids as well as dissolved organic carbon (DOC) were carried out in 2006 fiscal year for better understanding the dynamics of marine organic matter pool. The results are summarized as follows.Fluorescence dissolved organic matter (FDOM) was selected as a representative of major component of DOM in quantity but chromatographically-uncharacterizable component in quality, and the basin scale distribution of fluorescent intensity were clarified. The lowest fluorescent intensity was always found in surface waters, and it increased with increasing depth. The distribution of FDOM was similar to the of apparent oxygen untilization (AOU), and they are positively correlated in the mesopelagic and abyssal layers, indicating that FDOM is in situ produced to biological degradation of organic matter and is bio-refractory for〜900 yr. The production rate of FDOM is comparable to riverine input of DOC and burial rate of organic carbon to sediment.^<14>C concentration of dissolved lipid and DOC collected from the depth of 5 m were 72.32 ± 2.01 pMC (2600 yr BP), 93.48 ± 2.03 pMC (540 yr BP), respectively, at the innermost station in Ise Bay, and were 41.31 ± 1.64 pMC (7100 yr BP) and 95.25±2.09 pMC (390 yr BP), respectively, at the station on the mouth of Sagami Bay. Interestingly, ^<14>C concentrations of lipid were commonly lower than those of DOC, implying that the dynamics of dissolved lipid and bulk dissolved organic matter were different each other.