Study of Fishes in the Chung-Kung Stream: Species Distribution and Organochlorine Pesticide Residues

Abstract

In this study, we investigated the potential for reductive dechlorination of 2,4-dichlorophenol (2,4-DCP), 2,4,6-trichlorophenol (2,4,6-TCP), and pentachlorophenol (PCP) by municipal sewage sludge adapted to 2,4-DCP at different concentrations. 2,4-DCP was completely dechlorinated within 4 weeks. After 18 weeks' incubation, 2,4,6-TCP was also completely dechlorinated and the residue of PCP was 0, 44.46, 51.96% at 0.5, 5, and 50 μg ml¹ respectively. the 2,4-DCP adapted communities initially removed the ortho-chlorine from PCP of 5.0, 50 μg ml¹, following an ortho < para < meta order of chlorine removal. Intermediate products were 3,4,5-TCP, 3,5-DCP, 3-CP (3-chlorophenol), phenol, benzoate and hexanoic acids, whereas PCP (0.5 μg ml¹) indicated a preference for meta-chlorine removal. the intermediate product of 2,4,6-TCP at three concentrations were 2,4-DCP, phenol, benzoate and hexanoic acid. These products were identified by GC-MASS spectrometry. the effects of supplements, including sodium citrate (0.08 mM), sodium pyruvate (0.18 mM), sodium sulphate (0.14 mM) had a direct stimulatory effect on the dechlorination of 2,4,6-TCP and PCP after treatment for 4 weeks, but dechlorination was inhibited after 8 weeks.     

EEDs对鱼类性激素合成途径干扰作用研究进展

环境内分泌干扰物(environmental endocrine disruptors,EEDs)是一类可以改变生物体内激素的合成、释放、运输、代谢、结合、作用或清除等一系列生物过程的外源物质。性激素的生物合成需要一系列酶的参与,体内和体外研究表明,性激素合成途径中的类固醇生成酶是EEDs通过非性激素受体介导途径发挥内分泌扰乱作用的重要靶点,性激素合成途径的扰乱可能导致生物体生殖系统受损。本文综述了EEDs对鱼类性激素合成底物和类固醇生成酶的影响、信号转导机制及其生殖危害;并对性激素合成途径中促性腺激素调控机理、多种转录因子间的相互作用、不同物种间类固醇生成酶的差异以及各内分泌轴线的相互作用研究进行了展望,以期为EEDs通过非性激素受体介导途径发挥内分泌干扰效应的机制研究提供思路。     

Acute hematological toxicity of ivermectin to juvenile Clarias gariepinus

Abstract

Acute behavioral and hematological toxicity of ivermectin to C. gariepinus juveniles were assessed under static conditions at concentrations of 9 to 25?µg L^?1 for up to 4?days. Juveniles were highly sensitive to ivermectin, with an LC50 of 15?µg L^?1, culminating in spasms and paralysis. The hematological responses of packed cell volume, hemoglobin and red blood cell count decreased when compared to the control while the white blood cell count showed a biphasic trend. The mean corpuscular volume and mean corpuscular hemoglobin showed a mixed trend, while mean corpuscular hemoglobin concentration increased with increase in the concentration of the drug. Lymphocytes and neutrophils were also significantly (p?<?.05) increased. Ivermectin did not elicit any significant changes in monocytes, basophils and eosinophils. The observed changes confirm that ivermectin negatively affected the health of the fish. Therefore, real-time monitoring for early warning is recommended.     

基于不同评估方法的养殖池塘富营养化环境成本研究——以上海青浦地区常规鱼类养殖池塘为例

采用物料平衡法、置换成本法、条件价值评估法（CVM）和COD价格法对池塘养殖环境成本进行评估。结果显示,基于4种评估方法估算得到的池塘养殖环境成本由大到小依次为置换成本法（4 400元.a-1.hm-2）、COD价格法（4 191.99元.a-1.hm-2）、物料平衡法（3 925.76元.a-1.hm-2）和CVM法（2 007.8元.a-1.hm-2）,认为在不考虑时间和经济成本的前提下,基于COD价格法测算得到的结果可能最接近于环境成本的真实值。采用4种评估方法测得的环境成本占常规鱼类养殖经济总收益的6%～14%,表明采取相关措施防治水产养殖环境污染很有必要。     

Predicting barrier passage and habitat suitability for migratory fish species

Fish migrate to spawn, feed, seek refuge from predators, and escape harmful environmental conditions. The success of upstream migration is limited by the presence of barriers that can impede the passage of fish. We used a spatially explicit modeling strategy to examine the effects of barriers on passage for 21 native and non-native migratory fish species and the amount of suitable habitat blocked for each species. Spatially derived physical parameter estimates and literature based fish capabilities and tolerances were used to predict fish passage success and habitat suitability. Both the fish passage and the habitat suitability models accurately predicted fish presence above barriers for most common, non-stocked species. The fish passage model predicted that barriers greater than or equal to 6 m block all migratory species. Chinook salmon (Oncorhynchus tshawytscha) was expected to be blocked the least. The habitat suitability model predicted that low gradient streams with intact habitat quality were likely to support the highest number of fish species. The fish passage and habitat suitability models were intended to be used by environmental managers as strategy development tools to prioritize candidate dams for field assessment and make decisions regarding the management of migratory fish populations.     

航道疏浚泥悬浮液对黑鲷胚胎的发育及仔鱼摄食生长的影响

采用静水试验法,温度在20℃左右,并保持试验用水溶解氧为饱和溶氧的60%,用疏浚泥悬浮液与过滤海水按等对数间距稀释成4个体积浓度水平(1:2、1:10、1:50、1:200),同时以过滤海水为对照组,每一个浓度组设3个平行样本,对人工养殖的黑鲷Spaptls macrocephalus鱼卵和仔鱼进行毒性试验.试验结果表明:疏浚泥悬浮液对鱼卵孵化有一定影响,但不显著.仔鱼的全长和体重的增长与悬浮液浓度的变化并无十分明显的对应关系,只有当水体中的悬浮液达到一定浓度时,才显现出对仔鱼生长的影响作用.在仔鱼摄食过程中,悬浮液对全长生长产生的抑制或影响作用不显著,但高浓度的悬浮液则对体重增长产生了一定的抑制性,不过这是一种短暂性的影响,随着时间的延长,其作用逐渐减弱或消失.     

环境内分泌干扰物对鱼类性别决定的影响研究进展

水体中的环境内分泌干扰物能够影响鱼类性别决定过程,对鱼类产生明显的雌、雄性化效应.为深入研究环境内分泌干扰物对鱼类性别决定的影响及其机制,论文介绍了鱼类性别决定基因SRY和DMY基因在鱼类性别决定中的作用,以及Sox、DMRT、CYP和Vasa、Dax1、Foxl2等鱼类性别决定相关基因对鱼类性别决定的调控作用,综述了各类环境内分泌干扰物引起的鱼类雌、雄性化效应的最新研究进展,在此基础上探讨了环境内分泌干扰物影响鱼类性别决定的作用机制,并展望了该领域今后的重点研究方向.     

氟吡菌胺对斑马鱼的毒性效应

采用斑马鱼胚胎发育技术和传统毒理学方法, 研究了氟吡菌胺对斑马鱼胚胎、成鱼及仔鱼的毒性效应.结果发现,氟吡菌胺对3个阶段斑马鱼均具有致死能力,对仔鱼LC50(48h)值为0.204mg/L,成鱼LC50(96h)为0.286mg/L,幼鱼LC50(96h)为1.489mg/L.研究表明,0.0596mg/L以上浓度的氟吡菌胺对斑马鱼胚胎均有一定程度的致死效应,高浓度处理组胚胎出现心包囊肿、卵黄囊不吸收、黑色素沉积少及鱼体弯曲等症状;氟吡菌胺对斑马鱼成鱼进行14d暴露后,处理组成鱼体重下降,产卵量减少,有效卵量降低; 0.0298mg/L处理组144h子代仔鱼存活率虽然比较高,但存活鱼大部分出现心包囊肿、体弯曲等畸形.上述结果说明,水体中残留的氟吡菌胺对于斑马鱼各生命阶段的生长发育均具有潜在的危害.     

保安湖鱼体重金属和有机氯农药污染特征及健康风险评价

在湖北保安湖采集主要食用鱼类(团头鲂、鲫鱼、草鱼)样品,通过测定鱼体中的重金属(Cr、Cd、As、Pb、Hg、Cu、Zn)和有机氯农药(六六六(HCHs)、滴滴涕(DDTs))含量,基于不同评估模型分析了这3种鱼的污染特征和健康风险。结果显示,鱼样中Cr、Cu、Zn、As、Cd、Pb和Hg的含量分别为1.03～1.13、0.93～1.66、22.80～31.54、0.08～0.49、0.004～0.007、0.040～0.050和0.03～0.06 mg·kg~(-1);鱼样中HCHs、DDTs的含量为5.94～38.04和5.99～38.38 ng·g~(-1)ww。根据国家规定的有毒有害物质限量标准,团头鲂和鲫鱼中As分别超标0.2和3.9倍;鲫鱼体内HCHs和草鱼体内DDTs含量分别超标0.9和2.8倍;其他鱼样重金属和有机氯农药含量均未超过标准限值。总体来看,鲫鱼重金属严重污染,重金属综合污染程度的顺序是鲫鱼团头鲂草鱼;鲫鱼和草鱼体内有机氯农药(OCPs)达到重度污染,OCPs综合污染程度为草鱼鲫鱼团头鲂; 3种鱼样重金属和OCPs复合暴露条件下健康风险评估结果表明,食用3种鱼肉的致癌风险都大于10-6,即均存在一定的潜在致癌风险,致癌风险概率为鲫鱼草鱼团头鲂,同时,食用鲫鱼还存在非致癌健康风险,其污染来源及有效防治值得进一步研究。     

河鲈锚首吸虫及其宿主鳜鱼组织器官中铅含量的比较

利用原子吸收分光光度计分析了寄生鳜鱼（Sinipercachuatsi）鳃部的河鲈锚首吸虫（Ancyrocephalusmogurndae）及其宿主组织器官,包括肌肉、鳃、头肾和肝脏的铅含量.结果表明,来自三湖连江水库和牛山湖两个采样点的河鲈锚首吸虫的铅含量都显著地高于其宿主组织器官中的铅含量.在所检测的宿主组织器官中,肝脏的铅含量最高,在两个采样点分别为0.138和0.114μg/g（湿重）.河鲈锚首吸虫富集铅的机理及其较高水平铅含量的特点是否与其体外寄生的特性有关,尚有待于进一步研究.