Contamination of heavy metals would threaten the water and soil resources; phytoremediation can be potentially used to remediate metal contaminated sites. We constructed thePhragmites australisartificial floating wetlands outside the Qingcaosha Reservoir in the Yangtze Estuary. Water characteristic variables were measured in situ by using YSI Professional Pro Meter. Four heavy metals (copper, zinc, lead, and chromium) in both water and plant tissues were determined. Four heavy metals in estuary water were as follows: 0.03 mg/Kg, 0.016 mg/Kg, 0.0015 mg/Kg, and 0.004 mg/Kg. These heavy metals were largely retained in the belowground tissues ofP. australis. The bioaccumulation (BAF) and translation factor (TF) value of four heavy metals were affected by the salinity, temperature, and dissolved oxygen. The highest BAF of each metal calculated was as follows: Cr (0.091 in winter) > Cu (0.054 in autumn) > Pb (0.016 in summer) > Zn (0.011 in summer). Highest root-rhizome TF values were recorded for four metals: 6.450 for Cu in autumn, 2.895 for Zn in summer, 7.031 for Pb in autumn, and 2.012 for Cr in autumn. This indicates that theP. australisAFW has potential to be used to protect the water of Qingcaosha Reservoir from heavy metal contamination.

The hypothesis was tested that cryodamage occurs during the storage of semen at −196°C and that cryopreservation has a negative effect on the enzyme activity and motility of semen in the Russian sturgeon, Acipenser gueldenstaedtii. In addition, the aim of the study was to determine the activity of metabolic enzymes, including adenosintriphosphatase (total ATPase), creatine kinase (CK), succinate dehydrogenase (SDH) and lactate dehydrogenase (LDH), plus antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH‐Px) and glutathione reductase (GR). After cryopreservation (storage at −196°C), the motility and duration of semen fell and the total ATPase, SDH, LDH and CK activity in the spermatozoa was reduced. In the seminal plasma, however, total ATPase, SDH, LDH and CK activity increased markedly. Activity also notably increased in the group with no diluents or cryoprotectants. SOD, CAT and GSH‐Px activities also increased in the seminal plasma but dropped with regard to the spermatozoa, whereas the GR activity varied. The antioxidant enzyme activity trend between the groups with and without the addition of cryoprotectants was the same as in the metabolic enzyme activity. Cryopreservation had a great effect on the enzyme activity and motility of A. gueldenstaedtii semen; however, the cryoprotectant protected the semen during cryopreservation.