Long-term changes in nutrients, chlorophyll a and their relationships in a semi-enclosed eutrophic ecosystem, Bohai Bay, China

Yinhuan Qiao; Jianfeng Feng; Shangfa Cui; Lin Zhu

doi:10.1016/j.marpolbul.2017.02.002

Long-term changes in nutrients, chlorophyll a and their relationships in a semi-enclosed eutrophic ecosystem, Bohai Bay, China

Mar Pollut Bull. 2017 Apr 15;117(1-2):222-228. doi: 10.1016/j.marpolbul.2017.02.002. Epub 2017 Feb 6.

Authors

Yinhuan Qiao¹, Jianfeng Feng², Shangfa Cui¹, Lin Zhu¹

Affiliations

¹ Key Laboratory of Pollution Process and Environmental Criteria of Ministry of Education and Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China.
² Key Laboratory of Pollution Process and Environmental Criteria of Ministry of Education and Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China. Electronic address: fengjf@nankai.edu.cn.

PMID: 28185653
DOI: 10.1016/j.marpolbul.2017.02.002

Abstract

As the representative semi-enclosed bay of China, Bohai Bay has experienced severe eutrophication in recent decades. Monitoring data from 1995 to 2013 were analysed by generalized additive models (GAMs) to explore the temporal variations in nutrients concentrations, nutrient ratios, chlorophyll a (Chl a) concentrations and the responses of Chl a to the changes in nutrients in the spring and summer. The results showed that dissolved inorganic nitrogen (DIN) decreased from 1995 to 2000 but increased after 2000 in both the spring and summer, and soluble reactive phosphorus (SRP) decreased while the molar nitrogen/phosphorus (N/P) ratios (DIN to SRP) increased over the last two decades. Generally, P-limited phytoplankton growth was observed in the spring and summer and DIN was identified as the main pollutant constituent in Bohai Bay. Furthermore, negative correlations were found between DIN and Chl a in summer in Bohai Bay.

Keywords: Bohai Bay; Chlorophyll a; Generalized additive models; Nitrogen; Phosphorus.

MeSH terms

Bays*
China
Chlorophyll / analysis*
Chlorophyll A
Ecosystem*
Environmental Monitoring*
Eutrophication*
Nitrogen / analysis
Phosphorus / analysis
Phytoplankton
Seasons
Seawater
Water Pollutants, Chemical / analysis

Substances

Water Pollutants, Chemical
Chlorophyll
Phosphorus
Nitrogen
Chlorophyll A