生态环境学报Issue(4)：622-629,8.
长江口及邻近海域富营养化趋势分析及与环境因子关系
Analysis on the trend of eutrophication in the Changjiang (Yangtze River) Estuary and in the adjacent East China Sea and its relation to environmental factors
摘要
Abstract
Eutrophication has become an overwhelming phenomenon and an increase in nutrient concentration, noxious algal blooms or hypoxia in near-bottom waters have been of more frequent occurrence in the Changjiang (Yangtze River) Estuary and in the adjacent East China Sea. In spring and summer 2007-2009, six comprehensive investigations were undertaken in three zones (including Changjiang Estuary, Hangzhou Bay and Zhoushan fishing ground) in the estuary and in the adjacent sea. The eutrophication index, potential eutrophication and organic pollution index were used to present the eutrophication status. The results indicated that more than 70.0% of the waters were in an eutrophication state. Eutrophication status of the studied area showed an increase trend over the period from 2007 to 2009. The percentage of waters in eutrophication state was 77.7% in spring of 2007, and, has increased to 89.3% in spring of 2009. The percentage of waters in eutrophication state ranges from 89.3% to 100% in summer. Spatially, eutrophication index clearly decreased from the alongshore to the open sea. The Hangzhou bay was the most serious polluted sea in spring. The isolines of eutrophication index were dense both in Changjiang estuary and Hangzhou bay in summer, thus the eutrophication status was more serious in summer than those in spring. Based on potential eutrophication analysis, the eutrophication levels of the studied area mainly centralized on level III (eutrophication) and level VP (moderate P-limited potential eutrophication). In spring and summer, the percentage of area with level VP increased from 0.0% to 66.7%, which indicated the P-limited eutrophication level was more serious in summer. In addition, N/P ration has increased consistently from 9.1 to 50.9, which could affect the structure and growth of marine phytoplankton. In addition, the waters of the Changjiang Estuary and the adjacent East China Sea were in a serious pollution (main level five) state, according to organic pollution index. The percentage of waters in a serious pollution state was 50.0% in the Changjiang estuary in 2007, and has increased to 83.3% and 100.0% in 2009; and has increased from 60.0% and 80.0% to 100.0% in the Hangzhou bay, increased from 22.2% and 66.7% to 66.7% and 77.7% in the Zhoushan fishing ground, which indicated that the pollution level has increased gradually. Otherwise, more than 50% of the waters in the Changjiang estuary were belonging to the organic pollution index of level five, in the Hangzhou bay, 20% in the Zhoushan fishing ground. Thus, the organic pollution was most serious in the Hangzhou bay, moderate serious in Changjiang estuary, and least in the Zhoushan fishing ground. Spatially, the organic pollution index gradually decreased from west to east, from north to south. No significant correlations were observed between the eutrophication index, organic pollution index and the water salinity, dissolved oxygen, or pH. The spatio-temporal distribution of the eutrophication in the studied area was mainly influenced by the runoff and phytoplankton.关键词
长江口及邻近海域/富营养化/分析评价方法/时空分布/环境因子Key words
Changjiang Estuary and the adjacent East China Sea/eutrophication/methods of analysis and estimation/spatio-temporal distribution/environmental factors分类
资源环境引用本文复制引用
尹艳娥,沈新强,蒋玫,袁琪,平仙隐,徐亚岩,韩金娣,王云龙..长江口及邻近海域富营养化趋势分析及与环境因子关系[J].生态环境学报,2014,(4):622-629,8.基金项目
国家公益性行业(农业)科研专项经费项目 （农业）
