Characterization of ultraphytoplankton pigments and functional community structure in Xiangxi Bay, China, using HPLC-CHEMTAX

Abstract

To characterize the ultraphytoplankton community structure and understand its succession, we investigated photosynthetic pigment concentration and composition; algae phyla composition and abundance; and environmental factors in Xiangxi Bay (XXB) from February to December 2013. High-performance liquid chromatography (HPLC) analyses revealed eight diagnostic pigments: Fucoxanthin, Neoxanthin, Violaxanthin, Alloxanthin, Lutein, Zeaxanthin, Chlorophyll b and Chlorophyll a. The temporal differences between seven of the pigments (all excepting Neoxanthin) were significant (P < 0.05), and there were no significant spatial differences between the eight pigments (P > 0.05). A chemical taxonomy (CHEMTAX) calculation identified seven phyla of ultraphytoplankton: cryptophytes, chlorophytes, cyanobacteria, diatoms, euglenophytes, chrysophytes, and dinoflagellates. The temporal differences between five of the phyla (except chlorophytes and euglenophytes) were significant (P < 0.05), and there was no significant spatial difference between the seven phyla (P > 0.05). The redundancy analyses demonstrated that the key environmental factors for the succession were N-NH 4 C and P-PO 4 3-. Application of the HPLC-CHEMTAX method has provided the first analysis of ultraphytoplankton community structure in XXB, and our findings also show that environmental factors influence the succession of ultraphytoplankton over time.

Characteristics of the Ultraphytoplankton Community Structure and Its Environmental Response in the Three Gorges Reservoir (China) in 2014

“…Chlorophytes, Cyanophytes, and Dinoflagellates appeared in lower proportions. This is consistent with the results of Li (2014) and Liu et al (2017). It shows that Euglenophytes, Diatoms, Cryptophytes and Chrysophytes are the dominant species of Ultraphytoplankton in the Three Gorges Reservoir.…”

“…Therefore, August probably developed into the outbreak period of the ultraphytoplankton. Liu et al (2017) have found that the total chlorophyll a content of ultraphytoplankton was higher in the Xiangxi River Basin of the Three Gorges Reservoir in April and August, which is consistent with the results of this study. The research, which was put forth by Xiang Yingchun in 2014, had shown that, during 2011 and 2014 at the ZXH site, every month showed eutrophication.…”

“…Although this method has been widely used in the study of marine phytoplankton composition and abundance (Madhu et al, 2014;Agirbas et al, 2015), it has not been frequently used in fresh water. To explore the dynamics of the ultraphytoplankton community structure in the Three Gorges Reservoir, our group applied this technique, which can quickly and accurately describe the community structure of the ultraphytoplankton (Li, 2014;Liu et al, 2017).…”