Spatio-temporal Variation Characteristics Of Metazooplankton Community And Its Indicating Function To Water Quality In Hongfeng Reservoir And Baihua Reservoir

Zooplankton is a major part in aquatic organisms, and plays an essential role in the aquatic. In order to investigate the long-term dynamic change of matezooplankton’s community structure, the response to environment in Hongfeng Reservoir and Baihua Reservoir. Metazooplankton communities were studied four times in August 2014, October 2014, January 2015, April 2015. It’s spatio-temporal variation, the diversity and the response to environment were analyzed. The results fallowed:(1) In total, 26 rotifer species, 7 cladocera species and 5 copepoda species were recorded in Hongfeng Reservoir. 28 rotifer species, 8 cladocera species and 5 copepoda species were recorded in Baihua Reservoir. The similarity of metazooplankton species composition between two reservoirs were above 90%. Rotifer’s species and abundance accounted for large proportion, that were above 60%, followed cladocera, copepoda species detected in two reservoirs were the same, the lowest proportion.(2) The dominant species between Hongfeng Reservoir and Baihua Reservoir were similar. Keratella valga, Keratella cochlearis, Brachionus angularis, Brachionus calyciflorus, Trichocerca cylindrica, Polyarthra remata, Mesopyclops, Nauplius and Bosmina longirostris were the common dominant species of Hongfeng Reservoir. Keratella valga, Keratella cochlearis, Brachionus angularis, Brachionus calyciflorus, Asplanchna priodonta, Brachionus forficula, Polyarthra sp., Mesopyclops, Nauplius and Bosmina longirostris were the common dominant species.(3) The spatio-temporal variation of two reservoirs’ metazooplankton was obvious. The total abundance of Hongfeng Reservoir’s metazooplankton appeared highest in spring(April 2015), fallowed by autumn(October 2014) and summer(August 2014), lowest in winter(January 2015). The total abundance of Baihua Reservoir’s metazooplankton appeared highest in spring(April 2015), fallowed by summer(August 2014) and autumn(October 2014), lowest in winter(January 2015). The abundance of three groups in two reservoirs in warm season was larger than it in winter. In term of spatial pattern, the abundance at each point was different. In Hongfeng Reservoir, the abundance at dam site was highest, followed by Sanchahe site, Jiangjunwan site and Houwu site, the lowest at Yaodong site(Keratella cochlearis appeared largest at dam in April 2015). In Baihua Reservoir, the abundance at Yanjiaozhai site was highest, followed by Huaqiao site and Wharf site, the lowest at dam site(Keratella cochlearis appeared largest at Huaqiao site in April 2015,too). Overall, except for spring, the abundance of upstream was higher than downstream. The abundance in surface was higher than that in the bottom in two reservoirs, although with the exception that the highest abundance of Yaodong site was in the depth of 20 m during Autumn and Winter in Hongfeng Reservoir and the highest of wharf site was in 10-15 m during Winter in Baihua Reservoir.(4) The Shannon-Wiener index, Margalef index and Q index indicated that the water quality of two reservoirs was moderate pollution. But the water quality in Baihua Reservoir was a bit poor. The evaluation result was consistent with the result using comprehensive nutrition index.(5) Redundancy analysis(RDA) showed that the water temperature, pH, tatal nitrogen, total phosphorus, chlorophyll and potassium permamganate index were the main environment factors that influencing metazooplankton’s community structure variation in Hongfeng Reservoir. Water temperature, total nitrogen, total phosphorus, chlorophyll and transparency were the important factors in Baihua Reservoir. So nutrient and hydrological conditions affected two reservoirs’ metazooplankton community distribution, and the variation characteristics of metazooplankton’ community made effective response to environment factors.