The Study Of Affects Of Thermal Effluent On Pelagic Ecosystem By Mesocosm Experiments In Xiang Shan Bay

Affects of thermal effluent from power plant on the marine ecosystem is one of the important issues of the marine environmental science and marine management. Therefore, it was gradually attracted people's attention. The marine environment of around the sea area was changed by thermal effluent from power plant, then, the basic structure and function of the marine ecosystem was affected. There mainly is elevation of water temperature. In order to quantitatively evaluate the ecological damage caused by thermal effluent from power plant to maintain ecosystem health standards and the reconstruction of damaged marine ecosystems provide a scientific basis, then explore damage mechanism of the effect of thermal effluent from power plant on structure and function of the planktonic ecosystem. Under the funding of Marine Scientific Research Ministry of Science and Industry in the special fund for public welfare projects - monitoring and evaluation of coastal power plant pollution and ecological damage compensation technology, in this paper, take example of around the sea area of Ninghai Guohua power plants in Xiang Shan Bay in Zhejiang province, investigation through laboratory simulation and monitoring f by mesocosm experiments of pelagic ecology of ecosystem response to the thermal effluent from power plant. Comparative analysis parameter changes of structure and function of planktonic ecosystem. Establish biomass spectrum of plankton in Xiang Shan Bay, and evaluate health of pelagic ecosystem around the power plant by using method of indicators of the structure and function. Explore the response of marine planktonic ecosystem processes and mechanisms.The main research contents and results as follows:1.Through thermal simulation experiments under ideal conditions, the effect of elevation of water temperature on the Growth rate and mortality of Skeletonema costatum and Coscinodiscus jonesianus was studied. The response mechanism of the dominant species on the elevation of water temperature was analyzed. The result showed that optimum growth temperature of Skeletonema costatum and Coscinodiscus jonesianus are 26℃a nd 27℃.In the thermal shock of 33℃, the mortality rate of Acartia pacifica steuer as high as 80%.2.In the field conditions, response of marine planktonic ecosystem to thermal was studied by the method of mesocosm experimental. Comparison of parameter changes of structure and function of planktonic ecosystem, analysis level of damage of the producers of phytoplankton, the primary consumers of zooplankton and bacterial decomposition of planktonic ecosystem in the enclosure to thermal from power plant.(1)In the range of 25.20 ~ 26.40℃, effects of 0.25℃warming on the B, R and P of all plankton were not obvious, 0.52℃warming can elevate the R,P of microplankton and Nano-phytoplankton.(2) In the range of 25.20 ~ 26.40℃, effects of 0.52℃warming on the B, R and P of picoplankton were not obvious. (3) In the range of 25.20 ~ 26.40℃, The TPP/TR and turnover rate in the planktonic ecosystem were increased of 1.2 times and 1.5 times, separately..3.Comprehensive survey and monitoring of site power plant in Xiang Shan Bay Ninghai Guohua changes in the environment and resources and the impact factor of thermal from power plant caused by changes in ecological structure of the degree of scope and trend analysis and assessment of impact. The results showed that the more power from the power plant site near the type of plankton, biomass, Shannon diversity index, the lower, that is, the thermal effluent from power plant to some extent reduce the plankton community diversity and biomass, Even make certain species disappear.The overall trend of thermal effluent on planktonic ecosystems is the M1 over M2.4.Mesocosm experiments and field ecological survey and monitoring of the pelagic ecosystem structure and function parameters and the overall trend is promote and suppression, respectively, indicating that there is a field optimum temperature of planktonic ecosystem in the temperature distribution between the two regions. In the follow-up study, requires a combination of temperature distribution and the distribution of chlorine to analyze the phenomenon.5. Thermal from power plant in the quantitative evaluation of the ecological damage caused to maintain ecosystem health standards and the reconstruction of damaged marine ecosystems provide a scientific basis to explore the thermal from power plant on the planktonic ecosystem structure and function of the damage mechanism.