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1.
将人工繁育的"标准化"背角无齿蚌(Anodonta woodiana)移殖至太湖五里湖,并以仍养殖在未受污染的中国水产科学研究院淡水渔业研究中心南泉基地的同批蚌作为对照,进行为期9个月的主动监测研究.每3个月回收一次蚌样,应用电感耦合等离子质谱仪(ICP-MS)测定15种重金属(Al、Cr、Mn、Fe、Co、Ni、Cu、Zn、As、Mo、Ag、Cd、Ba、Tl和Pb)的含量.结果表明,南泉基地对照组和五里湖移殖组的蚌样对重金属均产生了明显的生物积累.培养3个月的五里湖移殖组蚌样中As的含量显著高于同期南泉基地对照组,而前者Mn、Fe、Zn和Ba含量显著低于后者;培养6个月的五里湖移殖组蚌样中Al和Pb的含量显著低于同期南泉基地对照组;培养9个月的五里湖移殖组蚌样中Pb含量显著低于同期南泉基地对照组.然而,南泉基地对照组和五里湖移殖组蚌样中重金属(Cr、Cu、As、Cd和Pb)含量均低于我国及国际上的相关标准.培养3、6和9个月的南泉基地对照组及五里湖移殖组蚌样的重金属污染指数分别为1.8、1.8,2.4、2.1和8.3、16.8,均值综合污染指数分别为0.0218、0.0289,0.0337、0.0218和0.0560、0.0732,属于正常背景水平,并且两水体蚌样的重金属污染指数和均值综合污染指数无显著差异,提示五里湖和南泉基地均未受到明显的重金属污染.  相似文献   

2.
滤水速率的快慢是决定滤食性河蚌对水质改善与否的关键,但受蚌龄大小、食物多少和季节变化的影响.以背角无齿蚌(Anodonta woodiana)为研究对象,设置幼龄蚌组、成年蚌组和无蚌对照组,在惠州西湖生态修复后的清水态和未修复的富营养化水体同时进行中型系统原位实验,测定了各处理组水层中氮、磷、总悬浮物(TSS)浓度和浮游藻类生物量(用叶绿素a(Chl.a)浓度表示)的季节变化,以研究蚌龄、食物和季节变化对背角无齿蚌水质改善的影响.结果表明,与对照组相比,背角无齿蚌提高了清水态水体总磷(TP)和铵态氮浓度,但对总氮(TN)、TSS和浮游藻类Chl.a浓度的影响不显著,表明其不能有效改善清水态水体水质;富营养化水体中,背角无齿蚌虽对水中TN浓度影响不显著,但显著降低了TP浓度、浮游藻类Chl.a浓度和TSS浓度;表明背角无齿蚌可改善富营养化水体水质;且富营养化水体中幼龄蚌的滤水速率显著高于成年蚌;幼龄蚌的滤水速率春季最大(0.132±0.018 L/(g·h)),夏季最小.因此,在富营养化水体修复前期,可通过放养本地滤食性河蚌,如背角无齿蚌,以改善水质,春季放养幼龄蚌更佳,为接下来的修复创造有利条件;而在生态修复后期的清水态水体中,单独的河蚌对水质改善效果不明显.本研究可为水生态系统保护和富营养化水体生态修复提供参考.  相似文献   

3.
袁家湖三角帆蚌Hyriopsis cumingii最佳育珠水层的试验研究   总被引:3,自引:0,他引:3  
封闭性育珠水体的各水层的理化和生物学性状不尽相同,因此,育珠蚌必须挂养在“最佳育珠水层”中。封闭型育珠水域具有明显而较稳定的最佳育珠水层。各育珠水域具有各自固有的最佳育珠水层。测定藻类的AGP值能预报该水域的最大浮游植物生物量。根据浮游植物生物量影响的透明度,可得出水域最佳育珠水层的关系式: 最佳育珠水层(cm)=透明度(cm)×0.8  相似文献   

4.
中国是东亚蚌类(蚌目:蚌超科)物种分布中心,共记录有26属.然而,在世界蚌目框架下,中国仍缺乏一个完整科学的蚌类分类系统.本研究基于多位点分子标记(COI、16S、28S)和线粒体基因组学重构聚焦于蚌超科的蚌目系统发育关系,ML、BI和BEAST系统发育结果均支持蚌科5亚科分类系统,即(((Ambleminae+Gonideinae)+Rectidentinae)+Unioninae)+Parreysiinae;珍珠蚌科2亚科分类系统,即(Gibbosulinae+Margaritiferinae);中国蚌类隶属蚌科4亚科(Gonideinae,Rectidentinae,Unioninae,Parreysiinae)13族和珍珠蚌科两亚科(Gibbosulinae,Margaritiferinae).基于化石标定的分子钟显示:蚌科物种分化时间为中三叠世(median=232.07 Ma),其中雕刻蚌亚科(Parreysiinae)起源和物种分化时间早于其他亚科;矩形蚌亚科(Rectidentinae)物种分化时间最晚,为晚白垩世(median=94.72 Ma);小方蚌亚科(Ambleminae)和隆脊蚌亚科(Gonideinae)最近共同祖先分化于晚侏罗纪世(median=144.69 Ma),珍珠蚌科起源于晚石炭世(median=312.61 Ma),物种分化于晚白垩世(median=91.59 Ma),中国蚌科现生物种最早起源时间可追溯到白垩纪(中国尖嵴蚌(Acuticosta chinensis),median=114.36 Ma).蚌超科线粒体基因重排分析显示:蚌超科线粒体基因组有4种基因排列方式(GO),珍珠蚌科独享一种(GO1);蚌科中Unioninae和Ambleminae共享一种(GO2);Gonideinae有2种基因排列方式(GO3和GO4),其中室蚌(Chamberlainia hainesiana)独享一种(GO4),其余物种共享一种(GO3).以往作为高阶元分类的贝壳形态、钩介幼虫形态以及育儿囊类型,并不能作为蚌科属及以上阶元分类依据.本研究重构了世界蚌目聚焦于蚌超科的系统发育关系和进化历史,建立了中国蚌类分类系统,为今后该类群区系多样性研究及资源保护提供了分类依据.  相似文献   

5.
对比研究了中国西部地区发生的6次中强地震前b值与C(n)值异常变化特征.6次地震前,b值和C(n)值都有异常显示.b值异常一般出现较早,最早出现在震前1年左右;C(n)值异常大多在震前半年至2~3个月出现.b值曲线异常形态一般不太典型,而C(n)值异常形态较典型,表现为峰值异常.地震前2种异常同时出现.还对计算上述参数的空间范围的选取及窗长和步长的选取进行了讨论.  相似文献   

6.
近年来太湖局部区域水体富营养化仍有加剧趋势,这可能与底栖动物生物扰动促进沉积物营养盐释放有关.耐污种霍甫水丝蚓(Limnodrilus hoffmeisteri)与常被用于生态修复的河蚬(Corbicula fluminea)均为太湖底栖动物优势种类,本文设计了双因素4组处理(对照组、河蚬组、霍甫水丝蚓组和混合组(霍甫水丝蚓和河蚬))的室外受控实验,研究在太湖2种种群分布交错区,河蚬能否对霍甫水丝蚓的生物扰动产生抑制效应.结果表明:霍甫水丝蚓扰动能显著增加水体总氮、总磷浓度,同时促进浮游植物生长;河蚬通过滤食和生物沉降作用显著降低水体总氮、总磷和悬浮物浓度,抑制浮游植物生长,从而促进了底栖藻类的生长;河蚬对霍甫水丝蚓生物扰动效应有抑制作用.  相似文献   

7.
用刚收割的水稻(Oryza sativa L.)秸秆浸提液代替水配制培养基培养铜绿微囊藻(Microcystic aeruginosa),追踪测定微囊藻的生物量、叶绿素a含量、光合速率、呼吸速率、膜透性、超氧物歧化酶(SOD)活性、光合膜自发荧光强度等相关生理生化指标的变化,研究水稻秸秆浸液对铜绿微囊藻的抑制作用.结果表明,质量比≥1/100(水稻秸秆/水)的水稻秸秆浸提液对微囊藻的生长有明显的抑制作用,表现如下:藻细胞生物量在实验过程中逐日降低,藻细胞叶绿素a含量和光合速率急剧下降,呼吸速率和超氧物歧化酶(SOD)活性呈先升高后下降的趋势,膜透性迅速升高,细胞光合膜自发荧光强度显著衰减.用不同的有机溶剂对该浸提液进行萃取,浓缩后用滤纸片法在固体培养基上做抑藻实验,乙醚和乙酸乙酯萃取液能明显看到抑藻圈,证实其中含有抑制物质.  相似文献   

8.
火烧作为调控因子,对植物群落结构和生态系统功能具有重要影响,但在湖泊湿地中研究较少.通过野外调查取样与实验室分析,探讨火烧对洞庭湖湿地主要群落类型——荻(Miscanthus sacchariflorus)和苔草(Carex brevicuspis)土壤化学性质的影响.结果表明:火烧后,苔草群落土壤硝态氮含量显著减少64.6%,有机质含量增加26.3%;而荻群落土壤与之相反,硝态氮含量增加186.9%,有机质含量减少22.9%.火烧后,苔草群落的全氮、铵态氮、全碳和全磷含量均显著增加,分别增加了75.4%、36.3%、102.7%和76.9%,而荻群落土壤与对照组间无显著差异.总体上,火烧对荻群落土壤养分影响不大,可作为芦苇场的一种管理方式,但火烧促进苔草群落土壤养分释放,有助于苔草群落提前萌芽和生长,并引起牲畜牧食增加.  相似文献   

9.
张民  史小丽  阳振  陈开宁 《湖泊科学》2021,33(4):1051-1061
随着我国湖泊治理力度的加大,太湖和巢湖的营养盐水平,特别是氮水平近年来明显下降,如2007年以后太湖总氮和近年来巢湖的氨氮水平都呈现下降趋势,但是2个湖泊水华蓝藻的优势种却向相反的方向演化,太湖的长孢藻(Dolichospermum)比例在增加,而巢湖的长孢藻比例却在降低,为阐明这种变化过程和驱动因素,本研究利用太湖(19932015年)和巢湖(2012 2018年)的历史数据分析了2个湖泊中的水华蓝藻——微囊藻(Microcystis)和长孢藻生物量的历史变化过程,并结合营养盐数据分析了影响2种水华蓝藻变动的驱动因素.结果显示:太湖和巢湖的微囊藻生物量多年来始终保持高位波动,近年来均有升高的趋势,这与2个湖泊磷的高位波动具有明显的相关性,磷是决定微囊藻生物量长尺度变化的主要驱动因素;太湖的长孢藻生物量呈现较大波动变化,2007年以后明显升高,巢湖的长孢藻生物量则明显下降,氮与长孢藻生物量呈现负相关关系,而且这种负相关仅在低磷浓度时具有显著性.微囊藻生物量对磷浓度变化敏感的正反馈响应是其水华形成的重要机制之一,在高温高磷条件下,微囊藻可以快速繁殖,并竞争性排除长孢藻,从而形成优势;而长孢藻可以通过温度生态位和固氮两种方式占据优势,在氮浓度相对较低,且温度低于微囊藻形成水华的温度范围时,长孢藻可以依靠温度生态位的优势形成水华,而在氮限制的条件下,即使在夏季高温时,长孢藻依然可以利用固氮作用形成水华,但是关键的温度阈值和开始固氮的氮浓度阈值仍不清楚.基于2种水华蓝藻对营养盐变化响应的差异,建议在进行蓝藻水华治理、污染削减过程中,应针对不同水华蓝藻的特性进行分时段分类别的营养盐控制策略.  相似文献   

10.
选取了两种常见的沉水植物狐尾藻和金鱼藻,通过测定其单株生物量、株高、根生物量/单株生物量、茎生物量/单株生物量和叶生物量/单株生物量,研究这两种沉水植物在2 mg/L的铵态氮持续处理4 d以及铵态氮胁迫解除后的生长情况.结果表明:铵胁迫阶段,与对照组相比,处理对狐尾藻各测定参数均无显著影响,而使金鱼藻株高显著增加.在铵胁迫解除阶段,与对照组相比,处理组狐尾藻单株生物量增加不显著,而金鱼藻单株生物量显著增加;处理组2种沉水植物株高均显著增加;处理组狐尾藻叶生物量/单株生物量显著增加,而根生物量/单株生物量显著减少,茎生物量/单株生物量保持不变.认为高光照环境下(约400μmol/(m2·s)),水体中铵态氮浓度短时间内(4 d)适当增加对沉水植物生长没有抑制作用;金鱼藻对高铵态氮浓度水体的适应能力较狐尾藻强.  相似文献   

11.
太湖鲚鱼和鲢、鳙鱼的食物组成及相互影响分析   总被引:3,自引:1,他引:3  
通过分析和比较太湖鲚鱼、鲢、鳙鱼的食物组成,研究了它们间的食物关系;并结合太湖历年鱼类渔获量资料,对渔获量变化间可能存在的相互影响进行了相关分析.结果表明:在9-12月份期间,鲢鱼、鳙鱼食物中微囊藻约占体积比的90%以上、浮游动物不足10%;用Pianka提出的公式计算鲢鱼和鳙鱼间的食物重叠系数为>0.99,相同食物组成比例为95.40%.而同期调查0 鲚鱼食物中微囊藻约占体积的15%-35%;如不计算微囊藻仅计算浮游动物的个数组成比则为:枝角类占89.77%±13 69%,桡足类占7.84%±11.53%,轮虫占2.39%±4.95%.而简单相关、偏相关分析表明:鲚鱼和鲢、鳙鱼数量变化间的负相关关系均达到显著水平.分析认为:在富营养化条件下,太湖的鲢鱼和鳙鱼以微囊藻为主要食物;而鲚鱼和鲢、鳙鱼食物中浮游动物的种类基本相同,可能存在对浮游动物资源的激烈竞争;它们种群数量变化间的相互影响是负向的,可能存在互相抑制.  相似文献   

12.
2002-2004年,在浙江衢州铜山源水库,对该库放养的美国大口胭脂鱼的生长情况进行了研究,结果表明,该水 库美国大口胭脂鱼的鳞片以环片的切割型为主要年轮特征.用刺网所捕的美国大口胭脂鱼渔获物中以Ⅱ、Ⅲ、Ⅳ龄个体为 主.体长和体重的关系式为:W=8.595×10~(-5)15 L~(2.662),Von Bertalanffy 生长方程的主要生物学参数:L_∞=36.54cm,W_∞= 1.245kg,K=0.6377,t_0=-0.261龄,体重生长的拐点年龄 t_1=1.92龄,拐点体重W_1=0.396kg.与池养鱼类生长情况相 比,铜山源水库的美国大口胭脂鱼生长较慢.  相似文献   

13.
Green-lipped mussels, Perna viridis, and Manila clams, Ruditapes philippinarum were sourced from “clean” sites in the Hong Kong region, depurated in a laboratory using uncontaminated filtered seawater for 8 days, and transplanted to a suspected gradient of chemically polluted sites in Hong Kong. After 14- and 28-days of field exposure, several antioxidant parameters including glutathione S transferase (GST), catalase (CAT), glutathione peroxidase (GPx), and glutathione (GSH) were quantified in gill and hepatopancreas tissues. Whole body tissue concentrations of polycyclic aromatic hydrocarbons (PAHs), petroleum hydrocarbons (PHCs), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCs) were determined in pooled site samples. Chemical analyses indicated that: (a) clams had higher levels of PAHs, PHCs, DDTs and PCBs, whereas mussels had higher hexachlorocyclohexane (HCHs) and there was no difference between species for dieldrin and remaining OCs; (b) Kat O should not be continued as a “clean” reference site for Hong Kong, because of the levels of contaminants measured and (c) PAH concentrations in the current survey were similar to those previously measured. Toxicological conclusions were: (a) antioxidant responses were different between species; (b) CAT and GST have highest utility in clams for field use in Hong Kong, whereas CAT in both gill and hepatopancreas tissue showed most potential in mussels; (c) significant induction of antioxidant responses over day 0 (excluding GPx in both tissues, and GST in mussel hepatic tissue); (d) groups of contaminants do not consistently induce antioxidant responses and (e) organochlorines and PCBs correlated significantly with CAT and GST in clam hepatopancreas and with CAT in mussel gill and hepatic tissue. Multivariate statistical techniques indicated little relationship between the site patterns for antioxidant responses and the contaminant gradients identified in body burden analysis.  相似文献   

14.
Man-made polybrominated diphenyl ethers (PBDEs) used as flame retardants in various consumer products may be harmful to marine organisms. Larvae of some marine invertebrates, especially invasive species, can develop resistance to PBDEs through altered protein expression patterns or proteome plasticity. This is the first report of a proteomics approach to study BDE-47 induced molecular changes in the invasive limpet Crepidula onyx. Larvae of C. onyx were cultured for 5 days (hatching to metamorphosis) in the presence of BDE-47 (1 μg L−1). Using a 2-DE proteomics approach with triple quadrupole and high-resolution TOF-MS, we showed that BDE-47 altered the proteome structure but not the growth or metamorphosis of C. onyx larvae. We found eight significant differentially expressed proteins in response to BDE-47, deemed the protein expression signature, consisting of cytoskeletal, stress tolerance, metabolism and energy production related proteins. Our data suggest C. onyx larvae have adequate proteome plasticity to tolerate BDE-47 toxicity.  相似文献   

15.
Species composition, relative abundance and life history of unionid mussels are compared between 1982–86 and 1915–19 in Lake Hallwil and the outflowing brook. The recent samples of unionid mussels were collected by divers, whereas the older ones were from a shell collection. The motivation for the comparison was that the trophic degree of the lake has changed since the beginning of the century from mesotrophic to highly eutrophic. The effects of this increased trophic degree of the lake on the life cycle of unionid mussels is discussed. Predictions are made about species composition and life history in the context of the ongoing lake restoration by the authorities.  相似文献   

16.
The effect of magnetic field-free space (MFFS) on the acoustic behavior of budgerigar (Melopsittacus undulafus) is obvious. The daily frequency of their cries in uniform MFFS (UMFFS) and non-uniform MFFS (NMFFS) decreases by 44.7±10.0% as compared with that in the geomagnetic field (GMF) on the average. The occupation rate of protesting cries (R op) in NMFFS decreases by 8.5%–20.3% as compared with that in GMF on the average and shows an adaptability variation. In 75% of the observation days, the R op in UMFFS increases by 16.2%–23.3% as compared with that in GMF. As for the effect of MFFS on the rhythmic habits of budgerigars, only the ending time of crying is affected to certain extent, 67 minutes earlier than in GMF on the average. This paper is supported by the Chinese Joint Seismological Science Foundation.  相似文献   

17.
通过研究太湖湖鲚的年龄结构、食物组成,结合太湖鱼类渔获量统计和环境检测资料,分析了1973-2002年间太 湖湖鲚渔获量变化的规律、原因及与生物环境间的相互关系.结果表明:1994年后湖鲚渔获量正以平均年增1430t 的速度 上升;种群中0~ 个体占99.04±2.21%(2003年)、99.08±0.80%(2004年);而0~ 湖鲚主要以浮游动物为食,其中枝角 类占食物总个数的89.77.80±13.69%.分析发现:湖鲚渔获量与 TIN、TN、COD 间的正相关关系均达到显著水平;与翘嘴 红鲌、银鱼产量间的负相关关系达到极显著水平;种群低龄化趋势加剧与捕捞强度不断升高相一致;浮游动物现存量有随 湖鲚渔获量升高而降低的趋势.  相似文献   

18.
香蒲、灯心草人工湿地的研究——Ⅰ.净化污水的效果   总被引:70,自引:5,他引:70  
本文研究了种植香蒲Typha angustifolia或灯心草Juncus effusus的人工湿地对城镇污水和人工不污染物的净化效果,调查了香蒲,灯心草不同季节的生长差异及高浓度污水冲击负荷对其生长的影响。香蒲,灯心草人工湿地净化城镇污水,出水水质总体上达到国家Ⅱ,Ⅲ类地面水标准,灯心草湿地对人工污水中凯氏氮,总磷,化学耗氧量地去除率维持在94%以上,氨氮的去除率为82.7%-99.7%;在正常  相似文献   

19.
我国深地资源电磁探测新技术研究进展   总被引:3,自引:0,他引:3       下载免费PDF全文
诸多研究表明我国深部资源潜力巨大,但目前的开发开采深度普遍停留在500 m以浅,开展"攻深探盲"是构建国家资源安全体系的有效途径.应用最先进的科学技术手段,提取深部地质信息,已成为我国当前地球物理科学研究的发展方向.作为地球物理学的重要分支,电磁法是矿产资源探查的主体手段之一.在分析我国现阶段航空、地面及海洋电磁探测技术进展的基础上,本文重点说明了极低频电磁法(简称WEM法),多通道瞬变电磁法(简称MTEM)和电性源短偏移瞬变电磁法(简称SOTEM)等电磁探测新技术.WEM法建立一套包括岩石层、大气层和电离层在内的全空间电磁传播理论,通过新研制的观测系统,获取地下10 km的地电信息;MTEM方法是地下埋深4 km目标体精细勘查的有效手段;SOTEM实现地下1.5 km深度范围内目标体的精细探测.通过多种电磁探测技术组合,可实现地下10 km深度范围内多尺度探测,达到"望远镜+放大镜+显微镜"探测效果.同时,本文指出进一步研发与新方法配套的装备、资料处理技术和大数据人工智能识别等将是我国电磁法未来的发展方向.  相似文献   

20.
Accidental oil spills from ships or rigs and inputs of effluent such as production formation water (PFW) are key perceived threats to tropical biota from industry activities. Scleractinian corals are an important functional component of tropical reefs and the abundance, diversity and resilience of coral communities can be used as an indicator of ecosystem health. In this paper, we report the effects of petroleum products, including water accommodated fractions (WAF) of crude oil, PFW and dispersant (Corexit 9527), on fertilization and larval metamorphosis of the widespread scleractinian coral, Acropora millepora (Ehrenberg, 1834) in laboratory-based assays. At 20% v/v PFW fertilization was inhibited by 25%. This concentration was equivalent 0.0721 mg l−1 total hydrocarbon (THC). In contrast, larval metamorphosis was more sensitive to this effluent, with 98% metamorphosis inhibited at the same concentration. Crude oil WAF did not inhibit fertilization of gametes until dispersant was introduced. Dispersed oil was slightly more toxic to fertilization than dispersant alone, suggesting toxicity to that event may be additive. The minimum concentration of dispersed oil which inhibited fertilization was 0.0325 mg l−1 THC. Larval metamorphosis was more sensitive than fertilization to crude oil. Although crude oil and dispersant inhibited larval metamorphosis individually, this toxicity was magnified when larvae were exposed to combinations of both. Crude oil inhibited metamorphosis at 0.0824 mg l−1 THC and at 0.0325 mg l−1 THC when dispersed in 10% v/v (dispersant/oil). Management of petroleum-related risks to spawning corals should consider not only the occurrence of the annual coral spawning event, but also the subsequent 1–3-week period during which most larval metamorphosis and recruitment occur.  相似文献   

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