冷排水中余氯对鱼类毒理效应和资源损失量估算方法的研究

Toxic Effects of Residual Chlorine from Cooling Water on Fish and Evaluation Method of Fishery Resources Loss

在实验室条件下模拟某液化天然气(liquefied natural gas,简称LNG)工程冷排水中余氯排放,并通过毒理实验研究海洋中余氯对大黄鱼(Larimichthys crocea)仔鱼和幼鱼的毒理效应。结果表明:在余氯浓度为0.14和0.20 mg·L-1时,仔鱼出现死亡现象,其他3个低浓度条件下仔鱼无死亡率;幼鱼死亡受余氯影响不显著。2009年调查结果显示,仔鱼和幼鱼的平均密度为8.75×106和5.39×103ind.·km-2。根据余氯扩散场预测数模,选取余氯0.01、0.05和0.10 mg·L-13个浓度计算其最大扩散面积,得到结果分别为0.248、0.047和0.010 km2,通过内插值法得到水体中对应的仔鱼死亡率分别为0.00%、0.00%和6.68%,幼鱼死亡率分别为4.13%、4.72%和0.92%。结合渔业资源损失评估公式W=D×V×M估算,该LNG工程余氯排放对临近海域仔鱼和幼鱼的损失量分别为5.84×105和6.77×103ind.。2010年同期调查结果表明,该海域仔鱼和幼鱼的尾数密度分别为40.63×106和13.89×103ind.·km-2,远高于2009年同期的资源密度,因此该LNG工程余氯排放短期内对海洋鱼类影响不显著。

Under laboratory conditions, the residual chlorine discharged from cooling water of liquefied natural gas （LNG） project was simulated. Toxic effects on Larimichthys crocea larval and juvenile were studied. The results showed that death of larval appeared when the concentrations of residual chlorine were 0.14 and 0.20 mg. L 1, whilethe mortality of larval was zero in other lower concentration of residual chlorine. The mortality of juvenile fish showed no significantly correlated with residual chlorine. According to the survey in 2009, the average density of larval and ju- venile fish were 8.75 x 106 and 5.39 x 103 ind. klTl＂ 2, respectively. Based on diffusion model, the concentrations of re- sidual chlorine in 0.01, 0.05 and 0.10 mg＇L μ corresponded with the maximal diffused area 0.248, 0.047 and 0.010 kmz, respectively. Using interpolation method, the mortality of larval and juvenile fish resulting from three concentra- tions of residual chlorine was calculated. The values were 0.00%, 0.00% and 6.68% for larval, and those were 4. 13%, 4.72% and 0.92% for juvenile fish. Combined with the evaluation formula W = D x V x M, the loss of larval and juvenile fish caused by residual chlorine discharged from LNG project were 5.84 x 105 and 6.77 x 103 ind, respec- tively. Survey data in 2010 showed that the average density of larval and juvenile fish were 40.63 x 106 and 13.89 x 103 ind.. km- 2 ,which were obviously higher than those in 2009. Obviously, residual chlorine discharged from LNG project had nn ~io＇niflt^ant aFfaet an oeann fish in ~hcwt tim~