【作者】 岳文洁；

【导师】 王朝晖；

【作者基本信息】 暨南大学 ， 环境科学， 2009， 硕士

【摘要】 为了评估拟除虫菊酯类农药对海洋生物以及海洋环境的毒性效应,了解拟除虫菊酯类农药对海洋生态系统以及海洋初级生产力的影响,研究了氯氰菊酯对重要赤潮藻类海洋卡盾藻（Chattonella marina）、锥状斯氏藻（Scrippsiella trochoidea）、中肋骨条藻（Skeletonemacostatum）和大型海藻龙须菜（Gracilaria lemaneiformis）的毒性效应及其对色素（藻红素或叶绿素a）、可溶性糖、可溶性蛋白含量以及超氧化物歧化酶（SOD）活性、丙二醛（MDA）含量等生理生化指标的影响,同时还探讨龙须菜对拟除虫菊酯的吸收吸附能力。结果表明,单种培养条件下,低浓度(≤10μg·L^-1)的氯氰菊酯对海洋微藻的生长具有明显的促进作用,而高于50μg·L^-1则产生较明显的抑制效应,但在暴露后期会出现一定的超补偿效应。而共培养条件下,中肋骨条藻对氯氰菊酯最为敏感,海洋卡盾藻次之,锥状斯氏藻抵抗能力最强。海洋卡盾藻只有在最低浓度1μg·L^-1浓度组的生长状况与对照组一致,其他浓度在对数生长期均低于对照组;锥状斯氏藻则在低浓度(≤10μg·L^-1)表现为促进作用,高浓度(≥50μg·L^-1)抑制;而中肋骨条藻农药处理组生长受到严重抑制,藻密度仅为对照组的10%以下。单独培养和共培养实验中,藻细胞所有生理生化指标均在暴露初期的6-12h较为敏感,24 h或48 h后趋于平稳。Ch1.α、可溶性糖、可溶性蛋白含量以及SOD活性等生化指标,在低浓度(≤5μg·L^-1)时均出现诱导现象,而高于50μg·L^-1时则呈现先抑制后恢复的现象。而氯氰菊酯对藻体内MDA含量均具有促进作用,浓度越高促进作用越强。结果说明对SOD和细胞内含物的抑制作用以及细胞膜结构损伤可能是氯氰菊酯对藻细胞损伤、抑制藻类生长的重要原因。海洋微藻的各种生化指标对氯氰菊酯的响应均较为敏感,但SOD和MDA对剂量反应更为敏感,氯氰菊酯对海洋卡盾藻SOD活性和MDA含量的最低作用剂量为10μg·L^-1,对锥状斯氏藻最低影响剂量更低,仅为5μg·L^-1和1μg·L^-1,对中肋骨条藻SOD和MDA的最低作用剂量均为5μg·L^-1。而对其他生长和生化指标的最低抑制浓度为50μg·L^-1。由此可见,SOD和MDA可作为监测环境中氯氰菊酯对藻类生长影响的敏感指标和生物标记物。龙须菜对氯氰菊酯的敏感性低于海洋微藻。当氯氰菊酯浓度低于50μg·L^-1时,龙须菜的生长均受到促进,直到农药浓度超过500μg·L^-1。后才逐渐表现出被抑制的现象。藻体内的藻红素、Ch1.α、可溶性糖、可溶性蛋白含量以及超氧化SOD活性、MDA含量等生化指标对氯氰菊酯均较敏感,其中SOD和Ch1.α、6 h最低作用剂量为5μg·L^-1,是龙须菜对氯氰菊酯响应的敏感指标。氯氰菊酯本身在水体中分解速率较快,未投放龙须菜的培养基中,氯氰菊酯96 h可降解水体中50%-70%左右的氯氰菊酯农药,而投放了龙须菜的培养基中,氯氰菊酯的去除率也只提高至52%-73%,说明龙须菜能够吸收吸附一定量的氯氰菊酯,但作用不大;另一方面,氯氰菊酯自身降解很快,可迅速降低至对生物无害的安全浓度。更多还原

【Abstract】 In order to assess the toxic effects of pyrethroid pesticides on marine organisms and marine environments,and to understand the influence of pyrethroid pesticides on primary production of marine ecosystem,the toxicities of cypermethrin on the growth of three important harmful agla bloom species Chattonella marina,Scrippsiella trochoidea,Skeletonema costatum and seaweed Gracilaria lemaneiformis were studied.The toxic effects of cypermethrin on biochemical parameters including contents of pigment,such as chlorophyll a（chl.a） and phycoerythrin（PE）, soluble sugar,soluble protein,malonyldiadehyde（MDA） and activity of superoxide dismutase superoxide dismutase（SOD）,were measured as well.Meanwhile the absorption and adsorption ability of G lemaneiformis on cypermethrin were studied.Results showed that,in mono-species culture condition,cypermethrin obviously accelerated the growth of microalga at concentration below 10μg·L^-1,and inhibited the growth significantly when concentrations were over 50μg·L^-1.However over-compensation growth occurred in the late exposure period under high cypermethrin concentrations.Under co-culture condition,S.costatum was the most sensitive species to cypermethrin,nest sensitive species was C.marina,and S.trochoidea had the strongest resistance.C.marina had the similar growth curve with the control group at the lowest concentration group(1μg·L^-1),and growth rates were lower than that in control group at concentration over 5μg·L^-1.The growth of S.trochoidea accelerated at lower concentrations(≤10μg·L^-1) and was inhibited at higher ones (≥50μg·L^-1).The growth of S.costatum was severely inhibited under the conjunct stress of cypermethrin and co-cultures,and the cell densities were less than 10%of the control group.All of the biochemical parameters were sensitive at the early 6-12 h exposure stages,and became to be stable after 24 h or 48 h exposure in both mono-cultures and co-cultures.The contents of Chl.a,soluble sugar,soluble protein and the activity of SOD were induced at lower concentrations(≤5μg·L^-1),and were initially inhibited and then recovered at high concentrations (≥50μg·L^-1).However,MDA content increased significantly with the increasing of concentrations.Results showed that the inhibition of SOD activity and cellular inclusions and the damage of cell membrane structure might be the important reasons for the toxicity of cypermethrin to algal cells.The results showed that all biochemical parameters measured in this study were sensitive to cypermethrin.Furthermore SOD and MDA were more sensitive.The lowest effective concentrations of cypermethrin to SOD activity and MDA content of were both 10μg·L^-1 for C. marinas,were 5μg·L^-1 and 1μg·L^-1 respectively for S.trochoidea,and were both 5μg·L^-1 for S. costatum.While the inhibition concentrations on growth and other biochemical parameters were all 50μg·L^-1.Therefore,SOD and MDA of microalga might be capable to be used as biomarks for early warning of cypermethrin pesticide contamination.The sensitivity of G lemaneiformis to cypermethrin was much lower than marine algae. Cypermethrin obviously accelerated the growth of G lemaneiformis at concentration below 50μg·L^-1,and inhibited the growth significantly over 500μg·L^-1.All biochemical indicators, including the cellular contents of PE,Chl.a,soluble sugar and soluble protein,MDA and SOD activity,were sensitive to cypermethrin.SOD activity and MDA content were the most sensitive parameters with the lowest effective concentrations of 5μg·L^-1.Cypermethrin decomposed fast in water that 50%-70%was decomposed within 96 hours,and the degradation rate increased slightly to 52%-73%in cultures with G lemaneiformis.Results showed that the removal rates of G lemaneiformis to cypermethrin were too low to function as an effective bio-filter.On the other hand,the pollution of cypermethrin would be decrease to the safety levels in marine environments,due to its quick self degradation.更多还原