大亚湾两种重要经济虾类热效应

Thermal effects of temperature on two commercially important shrimp species in Daya Bay

中国第1座大型核电站位于广东省大亚湾西侧,第1期工程于1994年初并网发电,第2期工程于2 0 0 3年5月正式投产,总装机容量为4 0 0 0 MW,经冷却系统排入大亚湾的热废水达2 0 0 m3/ s。核电站温排水的生态热效应问题引起人们普遍关注。针对这一问题进行了大亚湾海区斑节对虾(Penaeus monodon)和近缘新对虾(Metapenaeus affinis)两种重要经济虾类的高温热效应试验研究,测试了多项重要温度指标基准值。结果表明,斑节对虾和近缘新对虾的适宜生长温度范围均为2 9～35℃,最适生长温度(OGT)均为33℃;在不同的驯化温度下,斑节对虾和近缘新对虾的起始致死温度(IL T50 )分别为37.5～38.1℃和38.9～39.3℃;最高起始致死温度(UIL T50 )分别为38.1℃和39.3℃;临界热最大值(CTM)分别为4 2 .72～4 3.6 0℃和4 1.5 8～4 3.90℃;生长的最高周平均温度(MWAT)分别为34.7℃和35 .1℃;短期暴露最高温度(MTSTE)分别为37.12和37.89℃;在不同驯化温度下,斑节对虾主动趋向选择的最适温度为2 6 .4～32 .5℃,近缘新对虾为30 .7～33.1℃;起始致死温度、临界热最大值和选择的最适温度等与驯化温度呈正相关关系,随着驯化温度提高,其数值也增大,并逐渐趋向某一恒定的温度值。根据斑节对虾和近缘新对虾的热效应研究结果,结合这两种虾类的生?

The first nuclear power plant of China, Daya Bay Nuclear Power Plant (DBNPP), is located on the western shore of subtropical Daya Bay in Guangdong province. The phases one and two began commercial operation in early 1994 and May 2003, respectively. The total capacity of DBNPP is 4 000 megawatt (MW). Currently the power plant discharges thermal waste water into the Daya Bay at a maximum rate of 200m^3/s. The effects of discharged thermal water from the DBNPP on the marine organisms and ecological environment have received public attention. The present laboratory study tests the potential impact of the thermal discharge of condenser cooling water on the growth and mortality of two commercially important shrimp species, Penaeus monodon and Metapenaeus affinis. The results indicate that P. monodon and M. affinis have similar suitable growth temperature range of 29℃ to 35℃ and the same Optimum Growth Temperature (OGT) of 33℃; The Incipient Lethal Temperatures (ILT (50)) of P. monodon and M. affinis are 37.5～38.1℃ and 38.9～39.3℃, respectively, depending on the acclimation temperature. The Ultimate Incipient Lethal Temperatures (UILT (50)) of these two shrimp species are 38.1℃ and 39.3℃, respectively. The Critical Thermal Maximum (CTM) temperatures are again acclimation temperature dependent and are 42.72～43.60°C and 41.58～43.90°C for P. monodon and M. affinis, respectively. The Maximum Weekly Average Temperatures (MWAT) are 34.7℃ and 35.1℃, and the Maximum Temperatures for Short-Term Exposures (MTSTE) are 37.12℃ and 37.89℃, respectively, for P. monodon and M. affinis. P. monodon and M. affinis preferred temperatures of 26.4～32.5℃ and 30.7～33.1℃, respectively, from the different acclimation temperatures of 25℃ to 37℃. The results of our study suggest that at present the direct impact of thermal discharge water from the DBNPP on the growth and/or survivorship of (P. monodon) and M. affinis is small.