Ai-jun Wang1, Jian Chen, Dong-yi Li, Zhi-qiang Zhuo. 1. Open Laboratory of Ocean & Coast Environmental Geology, Third Institute of Oceanography, State Oceanic Administration, Xiamen 361005, China. ajwang@163.com
Abstract
Six short sediment cores were collected from different coastal wetlands of Quanzhou Bay in order to obtain the particle size distribution and median grain size by laser particle size analyzer, and the contents of total organic carbon (TOC), total nitrogen (TN) and total inorganic carbon (TIC) by element analyzer. Analysis results show that sediment in coastal wetlands of Quanzhou Bay can be classified as silt and clayey-silt, and the median grain size varies from 9.2 microm to 18.5 microm. The TIC content in bare flat sediments of Shuitou area is about 0.137%, which is higher than that in coastal wetland covered by Spartina alterniflora (0.014%-0.038%). TIC content decreases when grain size decreases in these sediments. Contents of TOC and TN vary from 0.939% to 2.057% and from 0.163% to 0.260% respectively. Spartina alterniflora has a strong absorption ability of carbon and nitrogen while mangrove has a weak one, and sewage discharge increases the TOC content in the sediments of Shuitou area which is higher than that of Luoyangjiang River estuary. Weak correlations occur between the contents of TOC and TN and median grain size; a typical strong positive relationship is observed between TOC and TN contents; and significant positive relationships of TN content with C/N ratio in Spartina alterniflora wetland and TOC content with C/N ratio in Spartina alterniflora wetland and bare flat are also observed. All these data indicate that the sources of TOC and TN in the coastal wetland sediments of Quanzhou Bay originate from sewage discharge and biogenic production.
Six short sediment cores were collected from different coastal wetlands of Quanzhou Bay in order to obtain the particle size distribution and median grain size by laser particle size analyzer, and the contents of total organic carbon (TOC), total n class="Chemical">nitrogen (TN) and total inorganic carbon (TIC) by element analyzer. Analysis results show that sediment in coastal wetlands of Quanzhou Bay can be classified as silt and clayey-silt, and the median grain size varies from 9.2 microm to 18.5 microm. The TIC content in bare flat sediments of Shuitou area is about 0.137%, which is higher than that in coastal wetland covered by Spartina alterniflora (0.014%-0.038%). TIC content decreases when grain size decreases in these sediments. Contents of TOC and TN vary from 0.939% to 2.057% and from 0.163% to 0.260% respectively. Spartina alterniflora has a strong absorption ability of carbon and nitrogen while mangrove has a weak one, and sewage discharge increases the TOC content in the sediments of Shuitou area which is higher than that of Luoyangjiang River estuary. Weak correlations occur between the contents of TOC and TN and median grain size; a typical strong positive relationship is observed between TOC and TN contents; and significant positive relationships of TN content with C/N ratio in Spartina alterniflora wetland and TOC content with C/N ratio in Spartina alterniflora wetland and bare flat are also observed. All these data indicate that the sources of TOC and TN in the coastal wetland sediments of Quanzhou Bay originate from sewage discharge and biogenic production.