热废水对大亚湾三种经济鱼类热效应的研究

INFLUENCE OF THERMAL POWER EFFLUENT ON THREE SPECIES OF FISHES IN DAYA BAY

对大亚湾3种重要经济鱼类包括黑鲷Sparusmacrocephalus、平鲷Rhabdosargussarba和细鳞Theraponjarbua的多项温度指标进行室内热效应模拟研究。结果表明：在驯化温度为25—33℃条件下,黑鲷、平鲷和细鳞3种鱼类的起始致死温度分别为34．96─36．42,34．78─35.62,38．75─39.39℃；最高起始致死温度分别为36.35,35.52℃和39.32℃；临界热最大值分别为38．08─40.50,38．28─40.40℃和42.40─43.64℃；最适生长温度分别为28,28℃和32℃;生长的最高周平均温度分别为30．78,30.51℃和34．44℃；短期暴露最高温度分别为34.04,33.57℃和37．90℃。根据黑鲷、平鲷和细鳞的多项温度指标,结合这些鱼类的生活习性分析和大亚湾基本环境特征的调查资料,就大亚湾核电站温排水对渔业资源影响的热效应问题进行初步探讨。

This paper reports the thermal effects of different temperatures on threecommercial species of fishes, including black porgy (Sparus macrocephalus), silverbream (Rhabdosargus sarba) and jarbua therapon (Therapon jarbua) in the Daya Bay,Guangdong Province, China. The results show that through acclimation undertemperatures of 25℃, 28℃, 30℃ and 33℃, the incipient lethal temperatures (ILT_50)range from 34.96℃ to 36.42℃ for black porgy, from 34.78℃ to 35.62℃ for silverbream and from 38.75℃ to 39.39℃ for jarbua therapon respectively. The ultimateincipient lethal temperatures (UILT_50) of these three species of fishes are 36.35℃,35.52℃ and 39.32℃ respectively. The critical thermal maximums (CTM) range from38.08℃ to 40.50℃ for black porgy, from 38.28 to 40.40℃ for silver bream and from42.40℃ to 43.64℃ for jarbua therapon respectively. The optimum temperatures forgrowth are 28℃ for black porgy, 28℃ for silver bream and 32℃ for jarbua theraponrespectively. The maximum weekly average temperatures (MWAT) are 30.78℃ forblack porgy, 30.51℃ for silver bream and 34.44℃ for jarbua therapon respectively.The maximum temperatures for short-term exposure (MTSTE) are 34.04, 33.57℃ and37.09℃ respectively. The thermal effects of different temperatures on these threespecies of fishes are comprehensively analyzed combining their ecological habits aswell as natural environmental characteristics of the Daya Bay. Reproductive periods ofblack porgy and silver bream are from Dec. to Feb. at 15-20℃ in the Daya Bay.Water temperature in the thermal field going 4℃ up as a result of thermal dischargewater from nuclear power plant (△T=4℃) will neither produce any clear harmfulinfluences on black porgy and silver bream, nor have any unfavorable effects ongrowth and development of juvenile and young jarbua therapon.