The Temporal And Spatial Distribution Of Fungi In Cage Culture Area In Dongsheng, Daya Bay And The Relation Between Fungi And Physical And Chemistry Factors

Daya Bay is one of the most important estuaries for large-scale cage culture in the eastern of South China Sea.The rapid development of mariculture resulted in the depravation of ecological status.Developing a method for counting the number of seawater fungi,we investigated the spatial and temporal distribution of fungi and relation between fungi and nutrients from June 2007 to June 2008.This study will give scientific data of studying environment protection of cage culture in Guangdong Province.Seawater was sampled one time every month to investigate chemical and physical factors, and 3 sites in area of cage culture and 3 sites in control area were set.The results showed that the numbers of fungi in sediment in the cage culture areas were 185 cell/mL-3350 cell/mL,which were more than 72.59%of those in the control area of 50 cell/mL-2380cell/mL.The numbers of fungi in seawater in the cage culture area were 170 cell/mL-810 cell/mL,which were more than 71.6%of those in the control area of 100 cell/mL-580cell/mL.The seasonal variation of the fungi was obvious,and the numbers of fungi were most in autumn and least in winter.The results showed that the number of fungi in sediment in the area of cage culture has positive correlations with organic materials(r=0.651,p＜0.05),kjeldahl nitrogen(r=0.5633,p＜0.05) and TP(r=0.8381,p＜0.01).The number of fungi in sediment in the control area has positive correlations with organic materials(r=0.7714,p＜0.01),kjeldahl nitrogen(r=0.7158,p＜0.01) and TP(r=0.7624,p＜0.01)The results also showed that the number of fungi seawater in the area of cage culture has positive correlations with temperature(r=0.7898,p＜0.01),amino nitrogen(r=0.766,p＜0.01),nitric acid(r=0.637,p＜0.05),phosphate(r=0.674,p＜0.01) and COD(r=0.6061,p＜0.05),while the numbers of fungi has a negative correlation with oxygen(r=-0.6186,p＜0.05).The number of fungi in seawater in the control area has positive correlations with temperature(r=0.7411,p＜0.01), amino nitrogen(r=0.679,p＜0.01),nitric acid(r=0.564,p＜0.05),phosphate(r=0.662,p＜0.01) and COD(r=0.552,p＜0.05),while has a negative correlation with oxygen(r=-0.6812,p＜0.01).