Distribution, Source Of Organic Carbon And Carbon-nitrogen-phosphors Interaction In Changjiang River Estuary And Jiaozhou Bay Waters

As the third largest river all over the world, Changjiang River inputs large amount of water and particulate matter to the East China Sea. Many important results have been got in the oceanography of Changjiang River estuary. The relationship between carbon sink-source process and biogenic elements in Changjiang River estuary became a key point of the research in Changjiang River-East China Sea interaction. In our research, DOC and POC distributions in seawater-freshwater mixed area of Changjiang River estuary were systemically studied by the data from field investigation of Changjiang River estuary in May 2003 and all year detection in Jiaozhou Bay from May 2003 to April 2004. Several new conclusions were draw from the cruises talked above.1. The exactly quantity of OC source strength were acquired in Changjiang River estuary especially the carbon source strength except that from Changjiang River input. The biogeochemical mechanism in controlling OC source and distribution was discussed by the data from investigation in Changjiang River estuary.Both DOC and POC changed in narrow ranges in FWA and flow into WMA. Other OC source joined in the flows in WMA and both DOC and POC reached their maximal values in this sea area. The fresh water which brought high quantity of DOC and POC was diluted by the seawater with low OC values in SWA. The DOC and POC concentrations are correlated to the salinity in this sea area.Daily OC source inputs to the East China Sea which were taken by Changjiang River were estimated at 5.78×10~9g of DOC and 1.06×10~9g of POC. Other OC source inputs to the East China Sea in WMA were estimated at 2.41×10~9g of DOC and 5.21×10~9g of POC. The other POC source was the suspending of surface sediments and the other DOC source was the transformation from POC.The DOC and POC daily changing trends and the influence elements were construed in this paper. The influence elements included: Changjiang River imports, assimilation of phytoplankton, suspending of surface sediments and transformation between DOC and POC.2. The interaction of particulate organic carbon-nitrogen-phosphorus was studied for the first time in Jiaozhou Bay. The biogeochemical distribution characteristics of particulate carbon-nitrogen-phosphorus in Jiaozhou Bay were construed in detail.PON in Jiaozhou Bay changed in narrow range. POP contents had patent monthly difference. POP from January to June was much higher than the contents from July to December. In the three different parts of Jiaozhou Bay, all the maximal contents of POP appeared in May and August and the minimal contents appeared in October. POP in Inside Bay, Outside Bay and Bay Mouth each two had a good positive relativity (Inside Bay/Outside Bay 0.8350, Bay Mouth/ Inside Bay 0.9556, Outside Bay/Bay Mouth 0.8017). This phenomenon pointed out that POP in different parts of Jiaozhou Bay has the same source. The monthly varieties of POC were in the same range of POP. In Inside Bay and Bay Mouth the maximum appeared in spring and in Outside Bay it appeared in summer and autumn. POC in Jiaozhou Bay were controlled by biological processes. According to the study areas, the strength of interaction between POC and POP in Inside Bay was higher the value between POC and PON. In a certain extent, the controlling elements of POC and POP were the same in Inside Bay, as the controlling elements of POC and PON were different.As both Changjiang River estuary and Jiaozhou Bay is typical estuary and bay all over the world, the biogeochemical process of biogenic element in the areas were valuable in studying of offing environment. Because of the complex influence elements, the research of the biogeochemical process in Changjiang River estuary and Jiaozhou Bay need the scientists to work harder and harder.