Publication Details

Category Text Publication
Reference Category Journals
DOI 10.2112/JCOASTRES-D-16-00023.1
Title (Primary) Analysis of Chlorophyll-a Correlation to Determine Nutrient Limitations in the Coastal Waters of the Bohai Sea, China
Author Mao, X.D.; Kuang, C.P.; Gu, J.; Kolditz, O. ORCID logo ; Chen, K.; Zhang, J.L.; Zhang, W.L.; Zhang, Y.F.
Source Titel Journal of Coastal Research
Year 2017
Department ENVINF
Volume 33
Issue 2
Page From 396
Page To 407
Language englisch
Keywords Algal bloom; trophic status; fuzzy integrated assessment; organic pollution index; temperate coastal water; water quality
UFZ wide themes RU5;
Abstract The coastal water of Qinhuangdao, a famous resort located in the NW of the Bohai Sea, China, suffered algal bloom for a consecutive 3 years by 2011, causing great economic loss. Based on measurements at 46 sampling points in the study's coastal area in May, August, and October 2011, the seasonal and spatial characteristics of the chemical indicators and chlorophyll-a (Chl-a) were analyzed. The chemical indicators for pH, chemical oxygen demand (COD), and reactive silicate (SiO3-Si) showed higher concentrations in the summer than in the spring and fall, whereas the nutrients of reactive phosphate (PO4-P) and dissolved inorganic nitrogen (DIN) presented complex seasonal characteristics under the combined influence of abundant nutrients from rivers and nutrient consumption by large algal bloom in August. Subsequently, two methods—a fuzzy, integrated assessment and an organic pollution index—were used to characterize the organic pollution. The trophic status of most coastal waters were oligotrophic and mesotrophic, and most coastal waters were clean in spring and summer, except in the vicinity of the harbor and estuaries, where the organic pollution index was generally high. Finally, Pearson correlation coefficients of various variables were analyzed, which demonstrated that, commonly, there was a significant positive correlation between COD and Chl-a. Because algal blooms in August changed the nutrients structure of the coastal waters, Chl-a, in a remarkably high concentration, had significant correlation with NO2-N, the atomic N/P ratio, and the atomic N/Si ratio. The algal bloom aggravated the current P limitation, and the atomic N/P ratio, the PO4-P concentration, and the COD can be selected as the three most-sensitive indicators of algal bloom in Qinhuangdao coastal water. These findings have provided scientific supports for local authorities who are taking measures to control pollution emissions and to prevent the recurrence of algal blooms.
Persistent UFZ Identifier
Mao, X.D., Kuang, C.P., Gu, J., Kolditz, O., Chen, K., Zhang, J.L., Zhang, W.L., Zhang, Y.F. (2017):
Analysis of Chlorophyll-a Correlation to Determine Nutrient Limitations in the Coastal Waters of the Bohai Sea, China
J. Coast. Res. 33 (2), 396 - 407 10.2112/JCOASTRES-D-16-00023.1