The Plankton Study Of Community Structure And Biological Diversity In Liusha Bay

Liusha bay lcated in the southwest of Leizhou peninsula zhanjiang Guangdong province, in the border area of the Xuwen west and the southwest of Leizhou (20o22,～20o31,N,109o55,～110o1,E). From March 2008 to February 2009,we studied plankton species composition, biomass and variation of the liusha bay. and the advantages of algae Chaetoceros mueller study on the absorption rate of nitrogen and phosphorus. We had the results as that:Annual average temperature of liusha bay was 26.27℃. From January to July, the temperature was Rising, in July, it reached to the highest 32.5℃. And then slowed down. The lowest temperature was in January, was 17℃. The transparency change in October the transparency was lowest, was 50 cm, and in December was highest, which was 219 cm.There were a total of 27 genera of phytoplankton , belong to five Phylum, the main dominant species are Chaetoceros,Pseudo-nitzschia pungens, Skeletonema costatum, Thalassiosira sp and so on. The contents of phytoplankton biomass varies from 0.11 mg/L to 23.67 mg/L. The mean value is 3.72 mg/L. The phytoplankton biomass has obvious changes by month and the highest biomass is in August, which the average biomass is 10.18 mg/L; Relatively low biomass are in March and April, which the average biomass are 0.45 mg/L and 0.39mg/L. The horizontal distribution of these phytoplankton biomass contents is also obvious, shown as the higher contents in 4th site,5th site,8th site and the respective mean value is 6.25 mg/L,4.40 mg/Land 6.43 mg/L. The lower contents in 1th site,9th site and the respective mean value is 1.51 mg/L and 1.46 mg/L. The phytoplankton diversity index is at a lower level, whether seasonal variations or the horizontal variations, the seasonal change were between 0.009 and 0.037, the mean value is 0.087; the different position changes between 0.017 and 0.287, the mean value is 0.1. The phytoplankton total cell number's plane distribution presents outside the bay to be higher than in the bay, the bay the flank to be higher than the inside, the east to be higher than the western basic pattern, This tendency is especially obvious in the phytoplankton peak season's summer and autumn. phytoplankton quantity and the water temperature assume the remarkable positive correlation, the correlation coefficient is 0.5847, explanation water temperature height immediate influence plant plankton cell's quantity. phytoplankton's total and the total nitrogen and the total phosphorus assume the certain extent the negative correlation relations, Because phytoplankton's growth follows inevitably total nitrogen and total phosphorus consumption, but the negative correlation relations are not obvious, this has the certain extent influence with the liusha bay geographical position.There were a total of 19 genera of zoonplankton,the main dominant species are Daphnia pulex, nauplius and so on. The contents of zoonplankton biomass varies from 0.08 mg/L to 7.24 mg/L. The mean value is 2.04 mg/L. The zoonplankton biomass has obvious changes by month and the highest biomass is in September, which the average biomass is 10.18 mg/L; Relatively low biomass are in April and June, which the average biomass are 0.52 mg/L and 0.73 mg/L. The horizontal distribution of these zoonplankton biomass contents is also obvious, shown as the higher contents in 4th site,7th site,8th site and the respective mean value is 2.64 mg/L,2.67 mg/L and 2.145 mg/L. The lower contents in 1th site,9th site and the respective mean value is 0. 91 mg/L and 0.98 mg/L. The zoonplankton diversity index is at a lower level, whether seasonal variations or the horizontal variations.Entire sea area's chlorophyll a varies from 0.09 g/m³ to 25.35 g/m³ ,including the quantitative change, the mean value is 2.94 mg/m³. The horizontal distribution of these chlorophyll a contents is also obvious, shown as the higher contents in 4th site,5th site,8th site and the respective mean value is 4.08 mg/m³,4.73 mg/m³ and 4.16 mg/m³. The lower contents in 1th site,9th site and the respective mean value is 1.51 mg/L and 1.46 mg/L. The chlorophyll a plane distribution change tendency is reduces gradually by the bay bottom to the bay to the baymouth content The chlorophyll a content has obvious changes by month and the highest biomass is in August, which the average content is 7.76 mg/m³; Relatively low biomass are in March and April, which the average content are 0.79 mg/m³ and 1.02 mg/m³. Liusha bay's primary productive forces varies from 6.89 mgC.m^-2.d^-1 to 1482.55 mgC.m^-2.d^-1 ,the mean value is 272.15 mgC.m^-2.d^-1Liusha bay sea area chlorophyll a and the nutrient salt regression analysis indicated that Between chlorophyll a and inorganic nitrogen's inverse correlation is also more remarkable, the correlation coefficient is - 0.219, p<0.001,and have no the remarkable relevance with between the inorganic phosphorus and the inorganic silicon. Chlorophyll a and between the phytoplankton total cell number assumes the remarkable positive correlation, correlation coefficient 0.350.Nitrogen on the growth of Chaetoceros were significantly affected by multiple comparisons that, in the nitrogen concentration of 30 mg/L when the best growth of Chaetoceros. Phosphorus on the growth of Chaetoceros muelleri significant impact, through the multiple comparisons that, in the phosphorus concentration of 3.0 mg/L is better when the growth of Chaetoceros.