Three cruises were carried out in the Yangtze Estuary and its adjacent areas in May, November, June during 2009-2010. The spatial variations of phytoplankton community structure were investigated based on RP-HPLC analysis of pigments and CHEMTAX processing of the pigment data. 21 kinds of pigments were detected, among which chlorophyll a, peridinin, fucoxanthin, 19'-butanoyloxyfucoxanthin, 19'-hexanoyloxyfucoxanthin, chlorophyll b, diadinoxanthin, alloxanthin and zeaxanthin were the major pigments in the Yangtze Estuary and its adjacent areas.
View Article and Find Full Text PDFThe modified wheat straw (MWS) was prepared and used to investigate the removal and the mechanism of Heterosigma akashiwo. The results showed that under the same loading of 0.10 g/L, the algal removal efficiency could reach 80% by MWS in 120 minutes, while 10% by the unmodified wheat straw.
View Article and Find Full Text PDFThe contents of cellular chlorophyll a (Chl-a), chlorophyll c (Chl-c), total coloured carotenoids (TCC) and the photosynthesis of Skeletonema costatum and Prorocentrum donghaiense under different nutrient conditions were studied. The results showed that both species in the low nutrient concentration conditions had lower cellular Chl-a, Chl-c and TCC content than those in the high nutrient concentration conditions. When the initial N/P ratio was 16/1 while the concentrations were different, the two species had different photosynthetic rate responses.
View Article and Find Full Text PDFThe effects NaH2PO4, adenosine disodium triphosphate (ATP), glucose 6-phosphate (G-6-P) and sodium beta-glycerophosphate (G-P) on the growth and phosphatase activity of Skeletonema costatum and Prorocentrum donghaiense were studied. The results showed that both species could utilize both dissolved inorganic phosphate (DIP) and dissolved organic phosphorus (DOP), and DOP had more effects on the growth of two species than DIP. For S.
View Article and Find Full Text PDFThe inhibitory effects of Grcilaria lemaneiformis on the co-cultured Scrippsiella trochoidea were determined under controlled laboratory conditions, and the possible mechanism was studied. Results showed that: (1) in the separating S. trochoiea-G.
View Article and Find Full Text PDFSystematic study of the sorption behavior of alkyl glucoside quaternary ammonium compound (AGQAC) on kaolin and bentonite showed that the isotherms of its sorption can be described very well by the Langmuir isotherm. The rate of alkyl glucoside quaternary ammonium compound sorption on kaolin and bentonite was very fast, it could reach equilibration in one or two minutes, and its saturate sorption amount was much enough to be used to modify clays. Then the influence of alkyl glucoside quaternary ammonium compound on the growth of Prorocentrum donghaiense, Amphidinium carterae, Scrippsiella trochoidea were studied, it was found that when its concentration was below 0.
View Article and Find Full Text PDFWe tested the influence of the preparation conditions of the quaternary ammonium compounds (QACs) modified clays on their capacities to remove red tide organisms, then discussed the mechanisms of the organo-clays removing red tide organisms. Hexadecyltrimethylammonium (HDTMA) improved the capacity of clays to flocculate red tide algae, and the HDTMA in metastable state enhanced the toxicity of the clay complexes to algae. The capacities of the organo-clays correlated with the toxicity and the adsorbed amount of the QACs used in clays modification, but as the incubation time was prolonged the stability of the organo-clays was improved and the algal removal efficiencies of the clay complexes decreased.
View Article and Find Full Text PDFWe studied the effects of fresh tissue and culture medium filtrate of Ulva pertusa (Chlorophyta) and Gracilaria lemaneiformis (Rhodophyta) on growth of 2 causative bloom species: Prorocentrum donghaiense and Alexandum tamarense, in laboratory conditions. Both U. pertusa and G.
View Article and Find Full Text PDFWe studied the effects of fresh tissue and culture medium filtrate of two species of macroalgae, Ulva pertusa (Chlorophyta) and Gracilaria lemaneiformis (Rhodophyta) on growth of Heterosigma akashiwo (Raphidophyceae) in co-culture. Both U. pertusa and G.
View Article and Find Full Text PDFConcentrations of heavy metals and organic matter in the bottom sediments of Jiaozhou Bay were determined and the average enrichment factors (AEFs) were used simultaneously to evaluate the extent of metal enrichment-contamination. Results show that heavy metal contamination in this bay could be divided into three groups: negligible to low contamination (AEFs < 2), which is the case of Zn (AEF = 1.11), Pb (AEF = 1.
View Article and Find Full Text PDFJ Environ Sci (China)
September 2006
The relationship between Alexandrium tamarense (Lebour) Balech, one of red-tide alga, and two strains of marine bacteria, Bacillius megaterium (S7) and B. halmapulus (S10) isolated from Xiamen Western Sea, was investigated by evaluating the growth state of A. tamarense and the variation of beta-glucosidase activity in co-culture system.
View Article and Find Full Text PDFThe distribution of matrix-bound phosphine in sediments was investigated in some selective sea areas of Jiaozhou Bay on Sep.6, 2003. Results show that the peak concentration of phosphine reachs to 143.
View Article and Find Full Text PDFHuan Jing Ke Xue
September 2004
Removal efficiencies of Prorocentrum donghaiense (Prorocentrum dentatum) by Hexadecyltrimethylammonium (HDTMA) bromide and organo-clay modified by HDTMA were identified. Moreover the toxicity of the unbound HDTMA and HDTMA plus clay to aquacultural organisms, Penaeus japonicus, was also tested. The results suggested that (1) The unbound HDTMA had an excellent ability to remove the red tide organisms.
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