Environmental drivers of heterogeneity in the trophic-functional structure of protozoan communities during an annual cycle in a coastal ecosystem

Xu, Guangjian,Yang, Eun Jin,Xu, Henglong Elsevier 2017 Marine pollution bulletin Vol.121 No.1

<P><B>Abstract</B></P> <P>Trophic-functional groupings are an important biological trait to summarize community structure in functional space. The heterogeneity of the tropic-functional pattern of protozoan communities and its environmental drivers were studied in coastal waters of the Yellow Sea during a 1-year cycle. Samples were collected using the glass slide method at four stations within a water pollution gradient. A second-stage matrix-based analysis was used to summarize spatial variation in the annual pattern of the functional structure. A clustering analysis revealed significant variability in the trophic-functional pattern among the four stations during the 1-year cycle. The heterogeneity in the trophic-functional pattern of the communities was significantly related to changes in environmental variables, particularly ammonium-nitrogen and nitrates, alone or in combination with dissolved oxygen. These results suggest that the heterogeneity in annual patterns of protozoan trophic-functional structure may reflect water quality status in coastal ecosystems.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The annual patterns of functional structure of protozoa showed clear spatial variations. </LI> <LI> Spatial variations in functional structure were significantly related to nutrient variables. </LI> <LI> Nutrients and dissolve oxygen may be the main drivers to shape the spatial differences. </LI> <LI> Spatial pattern of functional structure of protozoa may reflect water quality status. </LI> </UL> </P>

Colonization dynamics of periphytic ciliate communities across taxonomic levels using an artificial substrate for monitoring water quality in coastal waters

Xu, Henglong,Choi, Joon-Ki,Min, Gi-Sik,Zhu, Qinglin Cambridge University Press 2011 Journal of the Marine Biological Association of th Vol.91 No.1

<P>Taxonomic diversity and temporal patterns in abundance of periphytic ciliate communities across taxonomic levels were studied to monitor water quality in Korean coastal waters during April 2007. Specifically we compared two methods based on an artificial substrate (glass slide): the polyurethane foam enveloped slide (PFES) and the conventional slide (CS) systems. The results demonstrated that: (1) the colonization patterns of the ciliate communities at all taxonomic levels showed a lower variability in the PFES system than those of the CS system; (2) The taxonomic diversity (Δ) and taxonomic distinctness (Δ<I>*</I>) were significantly higher in the PFES system than those in the CS system; and (3) all four taxonomic diversity/distinctness indices represented lower variability in the PFES system than those of the CS samples. These findings suggest that the PFES system is more effective than the CS system for measuring the colonization patterns and taxonomic distinctness parameters that are increasingly used as potential indicators of water quality. This conclusion supports our previous suggestion that the PFES system is a better tool than the CS system for monitoring water quality in the marine ecosystem, using periphytic ciliates.</P>

An approach to analyses of periphytic ciliate communities for monitoring water quality using a modified artificial substrate in Korean coastal waters

Xu, Henglong,Min, Gi-Sik,Choi, Joong-Ki,Kim, Se-Joo,Jung, Jae-Ho,Lim, Byung-Jin Cambridge University Press 2009 Journal of the Marine Biological Association of th Vol.89 No.4

<P>Structural parameters of periphytic ciliate communities on a modified substrate were studied in Korean coastal waters during the period August-November 2007. In order to reduce the strong disturbances from tidal current and circulation in marine ecosystems, a modified slide method, named the polyurethane foam enveloped slide (PFES) system, was used to host ciliate communities. A total of 37 ciliate species, about half of which belong to the orders Hypotrichida and Cyrtophorida, were identified using living observation and silver impregnation method with this system. The sessile ciliates belonged to the orders Peritrichida and Suctorida, while the motile forms were represented primarily by the species of the orders Hypotrichida, Cyrtophorida and Pleurostomatida. The species diversity and evenness were significantly higher in the PFES system than those on the conventional slides (paired <I>t</I>-test: <I>t</I> = 2.384, 2.415; <I>P</I> < 0.05). Multivariate analysis revealed that the ciliate communities from both sampling systems had similar species composition, but represented significant differences in species distribution and temporal dynamics mainly due to the most dominant peritrich <I>Zoothaminium duplicatum</I>, which overly colonized the conventional slides. Results suggest that the PFES system is more effective than the conventional slide method for periphytic ciliate colonization with high species diversity, evenness and sensitive temporal dynamics mainly due to the reduction of disturbances from tidal current and circulation in marine ecosystems.</P>

Insight into tidal disturbance on colonization surveys for marine bioassessment using periphytic ciliates based on biological trait analysis

Zhong, Xiaoxiao,Xu, Guangjian,Min, Gi-Sik,Kim, Sanghee,Xu, Henglong Elsevier 2019 MARINE POLLUTION BULLETIN Vol.149 No.-

<P><B>Abstract</B></P> <P>To understand tidal disturbance on the colonization dynamics in community functioning of the ciliates in marine ecosystems, a 1-month survey was conducted using the conventional slide system (CS) and the polyurethane foam enveloped slide system (PFES) in Korean coastal waters. The results showed considerable differences were detected in community functioning parameters between the two systems. The vagile, flattened forms feeding on periphytic microalgae showed a higher community-weighted mean (CWM) value, and the solitary-colonial pattern represented a more stable temporal variability during the colonization in the PFES system than the CS system. The temporal shift in community functioning of the ciliates showed different ways in both systems. The functional diversity measures generally levelled off at more stable values in the communities with ages of 13–15 days in the PFES system than the CS system. These results imply that the PFES system may be a workable method for bioassessment in marine ecosystems.</P> <P><B>Highlights</B></P> <P> <UL> <LI> There were differences in community functioning between the CS and PFES systems. </LI> <LI> The vagile, flattened forms showed higher CWM values in the PFES system. </LI> <LI> The solitary-colonial pattern showed a stable temporal variability in the PFES system. </LI> <LI> The dynamics of functional diversity were found more stable in the PFES system. </LI> <LI> The PFES system was effective for reducing the disturbance due to tidal events. </LI> </UL> </P>

Determining Water Depths for Monitoring Coastal Water Quality Using Multiple Functional Traits of Periphytic Protozoa in Marine Ecosystems

Congcong Guo,Xiaoyun Bai,Mamun Abdullah Al,Mohammad Nurul Azim Sikder,Henglong Xu 한국해양과학기술원 2019 Ocean science journal Vol.54 No.1

Biological trait analysis (BTA) of protozoan communities has been used a useful bioindicator of environmental quality status in marine ecosystems. To determine the optimal water depths for bioassessment using multiple functional traits of periphytic protozoa, community functioning was studied at different water depths in the Yellow Sea, northern China. The community-weighted means (CWM) of bacterivores with small sizes showed an increasing trend from surface layers to the deeper ones, while those of algivores with medium and large sizes revealed an opposite trend, i.e., a decreasing trend from surface layers to deeper ones. However, with those of predators were distributed at depths of 2 to 3.5 m. There was a significant difference in the functional patterns, except for those at depths of 2 to 3.5 m (P > 0.05). All diversity indices except FDiv generally peaked and leveled off at either 2 or 3.5 m although they decreased with depth. The results suggest that sampling at depths of 2 and 3.5 m may be an optimal strategy for assessing water quality using the functional pattern of protozoa in coastal ecosystems.

Seasonal Shift in Community Structure of Periphytic Ciliates in Estuarine Waters in the Northern Bay of Bengal, Bangladesh

Mamun Abdullah Al,Rahman Muhammed Forruq,Aysha Akhtar,Md. Wahidul Alam,Mohammad Nurul Azim Sikder,Alan Warren,Henglong Xu 한국해양과학기술원 2018 Ocean science journal Vol.53 No.4

To investigate the seasonal heterogeneity of the periphytic ciliate communities, a 1-year baseline survey was conducted in the Karnaphuli River estuary, northern Bay of Bengal, Bangladesh. A total of 54 ciliate species were recorded, including seven common and 14 dominant species. Maximum species number was in autumn whereas maximum abundance was in winter; the minimum for both occurred in summer. Multivariate analyses, i.e., canonical analysis of principal coordinates (CAP) and principal co-ordinates analysis (PCoA), revealed a clear seasonal heterogeneity of community structure and environmental variables. Multivariate correlation analysis (RELATE) demonstrated that the community structure of the periphytic ciliate communities was significantly correlated with environmental variables, and best matching analysis (BIOENV) indicated that heterogeneity of community patterns was mainly driven by water temperature, pH, dissolved oxygen, total dissolved solids and nutrients. Species richness and diversity peaked in autumn whereas species evenness peaked in summer. These results suggest that environmental conditions shape periphytic ciliate community structure, which is a potentially useful bio-indicator of estuarine water quality.