Characteristics of distribution and variation of total nitrogen and phosphorous in seawater of the Jiaozhou Bay wetland

Abstract:

Based on the nutritional elements data of water surveyed in February，April，June，August，October and December，2009，the distribution and variation of total nitrogen(TN) and total phosphorous(TP) in seawater of the Jiaozhou Bay wetland were studied.The results showed that：（1）In the tidal range of the Dagu River，the content of TN and TP in water roughly decreased from upper stream to lower stream along the river course．In the inter-tidal area of the Jiaozhou Bay wetland，the regions with higher contents of DIN and DIP were basically located at the estuary of Dagu River and the area adjacent to it，and their contents and distribution were mainly controlled by runoff amount of Dagu River entering the sea．（2）There were apparent seasonal variations of TN and TP contents in the water of Jiaozhou Bay wetland．In the tidal range of the Dagu River，the mean content of TN was the highest in December，higher in February and the lowest in August.The mean content of TP was the highest in February，higher in December and the lowest in April．In the inter-tidal area of the Jiaozhou Bay wetland，the mean TN content decreased from February to August and increased from August to December，and the mean content of TP was the highest in February and lower with insignificant variation in other surveyed months．（3）The nutritional elements in seawater such as TN and TP in the Jiaozhou Bay wetland was mainly derived from the runoff of Dagu River entering the sea．