| 舟山渔场有色溶解有机物(CDOM)的三维荧光-平行因子分析 |
| 摘要点击 3516 全文点击 1654 投稿时间：2014-07-11 修订日期：2014-08-28 |
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| 中文关键词 有色溶解有机物(CDOM) 三维荧光光谱 平行因子分析 舟山渔场 腐殖化指数(HIX) 生物指数(BIX) |
| 英文关键词 chromophoric dissolved organic matter(CDOM) fluorescence excitation emission matrix parallel factor analysis Zhoushan Fishery humification index(HIX) biological index(BIX) |
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| 中文摘要 |
| 利用三维荧光光谱(EEMs)-平行因子分析(PARAFAC)技术研究春季舟山渔场有色溶解有机物(CDOM)的荧光成分组成、分布特征及来源. PARAFAC模型解析出舟山渔场CDOM由2类5个荧光组分组成,即类腐殖质成分C1(330/420 nm)、C2[(290)365/440 nm]、C3[(260)370/490 nm]及类蛋白质成分C4(285/340 nm)、C5(270/310 nm). 5种荧光组分的平面分布模式基本一致,在各层均呈现由近岸海域向远岸海域逐渐减小的趋势,但各层又略有差别. 表层高值区出现在杭州湾口外北部海域、虾峙门航道口外海域,且杭州湾口外北部海域的荧光值要高于虾峙门航道口外海域; 中层高值出现区域与表层相同,但杭州湾口外北部海域的荧光值要低于虾峙门航道口外海域; 底层从近岸向远岸梯度减小,高值区出现在舟山本岛附近海域. 各荧光组分的分布与盐度之间存在明显负相关关系,与叶绿素a的线性关系不明显. 分析表明,春季舟山渔场CDOM表、中层主要受长江输入和舟山工农业等人为活动排放影响,而底层主要受舟山工农业等人为活动排放影响. 从垂直分布模式上,CDOM在30°N断面上由中、表层水体向底层呈现逐渐减小的趋势,并在近岸和远岸海域都出现了高值区,且与盐度低值区、叶绿素a高值区相对应,反映该断面近岸区CDOM主要受长江输入影响,远岸区CDOM主要受生物活动影响; 在30 °N断面,CDOM分布模式与30.5°N断面基本类似,只是在近岸区域底层出现CDOM高值区,可能是由于潮汐、底层上升流等物理外力作用下,沉积物间隙水中高浓度的CDOM释放出来,使得靠近沉积物界面的底层水体中CDOM浓度升高. 5种荧光组分中, C1、C3、C4之间相关性较强,与C2、C5相关性相对较弱,说明C1、C3、C4在来源上具有相似性与C2、C5有一定的差异性. 春季舟山渔场CDOM腐殖化指数(HIX)的值较小,反映了春季舟山渔场CDOM的腐殖化程度较低,稳定性较差,在环境中存在时间较短; 生物指数(BIX)在舟山外海出现高值区,近岸海域出现低值区,反映出在近岸海域人类活动的影响较大,而在外海生物活动的影响较为明显. |
| 英文摘要 |
| The composition, distribution characteristics and sources of chromophoric dissolved organic matter(CDOM) in Zhoushan Fishery in spring were evaluated by fluorescence excitation-emission matrix(EEM) combined with parallel factor analysis(EEMs-PARAFAC). Three humic-like components[C1(330/420 nm)], C2[(290)365/440 nm] and C3[(260)370/490 nm)] and two protein-like components[C4(285/340 nm) and C5(270/310 nm)] were identified by EEMs-PARAFAC. The horizontal distribution patterns of the five components were almost the same with only slight differences, showing decreasing trends with increasing distance from shore. In the surface and middle layers, the high value areas were located in the north of Hangzhou Bay estuary and the outlet of Xiazhimen channel, and the former's was higher in the surface layer while the latter's was higher in the middle layer. In the bottom layer, CDOM decreased gradiently from the inshore to offshore, with higher CDOM near Zhoushan Island. The distributions of fluorescence components showed an opposite trend with salinity, and no significant linear relationship with Chl-a concentration was found, which indicated that CDOM in the surface and middle layers were dominated by terrestrial input and human activities of Zhoushan Island and that of the bottom layer was attribute to human activities of Zhoushan Island. The vertical distribution of five fluorescent components along 30.5°N transect showed a decreasing trend from the surface and middle layers to bottom layer with high values in inshore and offshore areas, which were correlated with the lower salinity and higher Chl-a concentration, respectively. On this transect, CDOM was mainly affected by Yangtze River input in coastal area but by bioactivities in offshore waters. Along the 30°N transect, the vertical distribution patterns of CDOM were similar to those of 30.5°N transect but there was a high value area in the bottom layer near the shore, attributing to the CDOM release from the marine sediment pore water to the water body because of physical force role like tidal, the underlying upwelling and so on. A strong correlation occurred between C1 and C3, C4, indicating that they had similar sources; a weak correlation was found between C1 and C2, C5, reflecting some differences among their sources. CDOM in Zhoushan Fishery in spring had low humification index(HIX) values, which reflected a low degree of humification, poor stability and a short resident time in the environment. For biological index(BIX), its higher values appeared in the offshore waters and the lower values occurred in the inshore area, reflecting a greater influence of human and biological activities, respectively. |
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