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

为了<14>更好地了解海洋有机质库的动态，于2006年对海洋类腐殖物质的荧光强度、溶解脂质的^ C和溶解有机碳（DOC）进行了测定。主要研究结果如下：选择荧光溶解有机物（FDOM）作为DOM的主要组分，阐明了荧光强度的流域尺度分布。最低的荧光强度总是发现在表面沃茨，它增加了深度。FDOM的分布与表观氧利用率（AOU）相似，在中层和深海层中呈正相关，说明FDOM是有机质生物降解的原位产物，是生物难降解的。沉积物中FDOM的产生速率与河流输入的DOC和沉积物中有机碳的埋藏速率相当。<14>5m深度的溶解脂和DOC的C浓度为72.32 ± 2.01pMC（2600年BP），93.48 ± 2.03 pMC在伊势湾最内侧站，平均为41.31 ± 1.64 pMC在相模湾口站，平均海水盐度分别为95.25±2.09 pMC（390 yr BP）和7100 yr BP。有趣的是，<14>脂质的^ C浓度普遍低于DOC，这意味着溶解脂质和溶解有机质的动态彼此不同。

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.