Study Of Bacterial Productivity And The Spatial And Temporal Distribution Of Bacteria,Vibrio And Heterotrophic Bacteria In Zhelin Bay

Zhelin Bay with water area of 68km" is a stable and semi-obturate estuary of Shantou, Guangdong province. Since the lee of Zhelin Bay is good, mariculture increased rapidly there. The increase of mariculture resulted in the exacerbation of estuarial eutrophication incessant depravation of ecological status. From November in 2002 to October in 2003, the thesis investigated the spatial and temporal distribution of bacteria, vibrio bacteria&heterotrophic bacteria in water and sediment. The bacterial productivity and nutrient factors (DIN, PO43-P)were examined within Zhelin Bay. The thesis analyzed their ecological status and their variational trend in the future, and will ulteriorly give basic data for studying and formulating the strategies on continuing development and estuarial protection of mariaquaculture in Zhelin Bay. At the same time, this can provide more valuable information on how to prevent disease of mariaquaculture.Locale inverstigation of physical and chemical factors of water was carried out at nine station one time every month. Sampling was finished during high tide (?1.5hr)period . Take the sampling to the laboratory under low temperature circumstances, then, census the total numbers of bacteria by fluorescence microscope and vibrio by selection technique of plate cultivation. The results showed that the numbers of bacteria, vibrio were varying in the water and in sediment. Bacterial numbers in the large-scale filter-feeding marine fish culture and oyster culture were more than those in the outer bay. In addition, the seasonal variation of the bacteria was prominence, highest bacterial numbers occurred in summer,while lowest occurred in winter.The analyses showed that bacterial numbers were positive correlation with water temperature(r=0.89124, p<0.01), also the positive relation exited among the dissoved of nitrogen and phosphate. While bacterial numbers with the dissolved oxygen (r=-0.66107, p<0.01) was negative correlation. Correlations of bacterial productivity with bacterial numbers and temperature were positive. The rate of vibrio andheterotrophic bacteria is 0.0195. The water of Zhelin Bay was polluted seriously, and it reached the level of eutrophication or excess eutrophication.