Abstract: In this paper, large-scale cultivation of Sargassum vachellianum in sea field and its effects on water environmental factors were studied. The results showed that the suitable water depth for S. vachellianum growth was 1.5-2.5 m, and the optimal water depth was 2 m. The fronds of seaweeds grew faster in spring and autumn and declined in summer. In May 2014, the highest specific growth rate of cultivating fronds and wild fronds reached up to 6.8%·d^-1 and 5.9%·d^-1, respectively, and cultivating fronds grew faster and matured earlier than wild fronds. In 2014, the IN, IP, TN, TP, COD and Ch-a mass concentrations in all stations except the 1st and 7th stations decreased significantly compared with in 2013 (P<0.05). DO mass concentration and SD increased by 4.52% and 8.09% (P<0.05), and COD and Chl-a mass concentration decreased by 18.75% and 43.51%, respectively, and the highest mass concentration of Chla was about 1.55 μg·L^-1. The quality of the sea waters was improved significantly after S. vachellianum cultivation. This study provided a theoretical basis for cultivation of S. vachellianum and sea water quality environment bioremediation with seaweeds.

Key words: remote sensing, simulation and forecast, CA-Markov model, Ebinur Lake Wetland Nature Reserve, land use/cover