Ciliated protozoa play important roles in micro-ecosystems, especially in marine biotopes. However, few studies have been carried out on the periphytic, or aufwuch, forms in mariculture waters so far. In this study, we sampled periphytic ciliate communities in two closed mariculture ponds (ponds CP1 and CP2) and a natural seawater reservoir (pond RP) using a glass slide method to evaluate their colonizing processes and general ecological features, as well as their application as water quality indicators. We analyzed species compositions, structural parameters (species number, richness, diversity, evenness, abundance and dBP) and functional parameters (G, Seq and T90%). Pond RP was characterized by higher levels of structural parameters (except for abundance and dBP) and more equal proportion of the major taxonomic groups. The values of Seq were significantly higher in pond RP and similar in both pond CP1 and CP2. It was also demonstrated that environmental factors, including NO2-H, NO3-H, NH3-H, soluble reactive phosphate, temperature and pH, were the first principal factors affecting the communities. Among them, temperature and chemical factors were all significantly and negatively correlated with species number (P<0.01), richness (P<0.01), diversity (P<0.01), and positive correlated with abundance (P<0.01). Opposite correlations between pH and structural parameters were observed. This study showed that there were significant differences in species composition, structural parameters and functional parameters of the periphytic ciliate communities among the ponds, which were in agreement with the water quality. Results of this study confirmed the periphytic ciliate communities to be useful bioindicators of water quality in intensive mariculture waters.
Variations in physical-chemical factors, species composition, abundance and biomass of nano-and micro-phytoplankton assemblages, as well as their responses to environmental factors, were investigated over a complete cycle (6 months) in a semi-enclosed shrimp-farming pond near Qingdao, northern China. The aim was to establish the temporal patterns of phytoplankton communities and to evaluate protists as suitable bioindicators to water quality in mariculture systems. A total of 34 taxa with nine dominant species were identified, belonging to six taxonomic groups (dinoflagellates, diatoms, cryptophyceans, chlorophyceans, euglenophyceans and chrysophyceans). A single peak of protist abundance occurred in October, mainly due to chlorophyceans, diatoms and chrysophyceans. Two biomass peaks in July and October were primarily due to dinoflagellates and diatoms. Temporal patterns of the phytoplankton communities significantly correlated with the changes in nutrients, temperature and pH, especially phosphate, either alone or in combination with NO3-N and NH3-N. Species diversity, evenness and richness indices were clearly correlated with water temperature and/or salinity, whereas the biomass/abundance ratio showed a significant correlation with NO3-N. The results suggest that phytoplankton are potentially useful bioindicators to water quality in semi-enclosed mariculture systems.
许恒龙MIN Gi-SikCHOI Joong-KiAL-RASHEID Khaled A. S.林晓凤朱明壮
