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1.
悬浮物对虾夷扇贝致死效应的研究   总被引:5,自引:0,他引:5  
虾夷扇贝原产于太平洋西部和北部的俄罗斯、朝鲜及日本沿岸等地,适于在低温、高盐度海洋环境中生存、生长。为确定虾夷扇贝适宜的生存环境,研究了悬浮物对虾夷扇贝的致死作用。结果表明:(1)悬浮物对虾夷扇贝的急性致死效应(72h)不强;(2)高浓度悬浮物对虾夷扇贝具有很强的慢性致死作用。  相似文献   

2.
海湾扇贝自身污染的研究   总被引:7,自引:1,他引:7  
在实验室条件下,进行了海湾扇贝自身污染的研究。在海湾扇贝生长的生态过程中,出现了来源于自身新陈代谢产物的有机和无机氮污染,即自身污染。导致pH和DO的降低,COD和BOD的增加,以及病原生物弧菌的大量繁殖。  相似文献   

3.
杨卫华 《环境科技》2008,21(6):30-33
基于对扇贝养殖的环境影响的分析,对扇贝筏式养殖的无机营养盐污染负荷的估算方法做了改进,把养殖海区沉积物垂直扩散再生的无机营齐盐和养殖扇贝排泄所产生的无机营养盐之和作为扇贝筏式养殖的N,P污染负荷量。并根据此方法时胶州湾扇贝养殖的N,P污染负荷量进行了分析和估算,为胶州湾扇贝养殖所产生N,P无机营养盐的浓度分布的模拟提供源强项。  相似文献   

4.
论文在对海岛海域适宜发展海洋农牧化生产的空间资源、环境因子和海洋生物资源进行评价的基础上,对长山群岛海洋农牧化生产的发展过程、生产特征进行了详尽的分析。尤其对贝类养殖中的扇贝生产所具有的全国意义以及不同扇贝品种的海域养殖差异等也进行了论述。论文应用主成分分析方法,对长山群岛中各主要海岛的海洋农牧化生产的综合实力水平进行了评估,并在此基础划分出北部以王家、石城,中部以广鹿、大、小长山,南部以獐子、海洋3个海洋农牧化生产海域。根据各农牧化区的海域资源、环境以及生产结构特征,对各岛提出了主要养殖品种的布局与今后发展对策。  相似文献   

5.
石油对海湾扇贝影响的海上围隔实验   总被引:3,自引:0,他引:3  
采用海上围隔实验方法观察了石油对海湾扇贝行为、生长的影响,并测定了其体内石油的蓄积量。当海水中油浓度在0.16mg/L以下时,对海湾扇贝的行为和生长并无影响,当水中油浓度升到0.16mg/L以上时,扇贝的行为和生长均受到一定的影响.在实验浓度范围内,水中油浓度越高扇贝生长越缓慢,体内油的蓄积量也越高。在水中油浓度为1.99mg/L情况下,短期内扇贝还不致引起死亡。扇贝体内油的蓄积量最多可达到999×10-3湿重。  相似文献   

6.
日照石臼扇贝养殖水域夏季污染调查分析   总被引:2,自引:0,他引:2  
1998年7月中旬,山东省日照市东港区石臼扇贝养殖区出现养殖的栉孔扇贝大面积死亡。死亡顺序由岸边开始向里面蔓延;死亡程序岸边大于里面,介体大的大于个体小的。为弄清扇贝死亡的原因,1998年8月,进行了该水域的环境综合调查。本文报道了污染环境的调查结果,COD平均值为0.98%mg/L;石油类为6.27ug/L;挥发酚为1.69ug/L;悬浮物为10.64mg/L;Cu为6.40ug/L;Zn为9;  相似文献   

7.
本文初步探讨了赤潮生物污染海水使扇贝大量死亡的结果。用硫酸亚铁处理赤潮生物污染的海水可使海水净化,使人工养殖扇贝育苗获成功。  相似文献   

8.
疏浚物对栉孔扇贝急性致死量的实验研究   总被引:1,自引:2,他引:1  
本文探讨实验室室条件下疏浚物对栉孔扇贝96h半致死浓度以及试验条件的筛选,实验结果表明,疏浚物粒径小于63μm,海水中悬浮物浓度为10%,水温(20±1)℃,pH8.0-8.3,盐度29-30,充氧条件下,栉孔扇贝96h内的死亡率为63%。  相似文献   

9.
长海海域浮筏养殖虾夷扇贝生物沉积速率的现场研究   总被引:1,自引:0,他引:1  
为评价浅海高密度、规模化浮筏养殖贝类的生物沉积作用及其环境生态效应,本文运用生物沉积物捕集器对长海海域浮筏养殖虾夷扇贝的生物沉积速率进行了四个季度的现场测定。结果表明,同一养殖区不同排筏虾夷扇贝的生物沉积速率有很大不同,呈现出由低排筏到高排筏逐渐降低的趋势;不同季节虾夷扇贝生物沉积速率变化明显,秋季最高,冬季最低。海水中悬浮颗粒物浓度及水温是影响扇贝生物沉积速率的主要因素。  相似文献   

10.
大亚湾和大鹏湾麻痹性贝类毒素动态分析   总被引:14,自引:8,他引:14  
于1997~1999年在大亚湾和大鹏湾的主要贝类养殖区设立了四个采样点,以华贵栉孔扇贝和翡翠贻贝为对象逐月采样,用美国分析化学家协会推荐的生物测定法进行麻痹性贝类毒素测定。结果显示,1999年1月~1999年6月大亚湾东山海域的扇贝消化腺毒素含量为1263~105Mu/g,剔除消化腺后的软组织毒素含量为13.4至低于1.7Mu/g,消化腺和其他软组织毒素含量的加权平均值为7.7~117Mu/g,高  相似文献   

11.
Routine assessments of sport fish populations are necessary for managers to determine whether populations are meeting objectives. An effective assessment technique should entail rating parameters that are measurements of, or are influenced by the three rate functions of recruitment, growth, and mortality. It will enable managers to determine which rate functions may be preventing a population from achieving stated objectives and help them determine if additional management or research efforts are needed. The first requirement of an effective assessment technique is a standard sampling method that captures all sizes of fish that are present in the population. The sampling method should detect changes in population density and size structure, which will then be reflected in sample length frequencies. Other important criteria are the selection of appropriate parameters from the sample data and the setting of objectives for those parameters. An ideal assessment should include parameters that depict recruitment levels, adult density, growth rate, age structure, and size structure. The parameter value should be easy to calculate from sample data. Use of an assessment for white crappies in Missouri’s large reservoirs showed that growth was generally good, but mortality was high. Subsequent research indicated that angler exploitation was the cause of the high mortality, which led to the successful implementation of restrictive harvest regulations.  相似文献   

12.
This paper analyses the impact of the 2003 European heatwave on excessive human mortality in Portugal, a country that presents a relatively high level of exposure to heatwave events. A total of 2399 excessive deaths are estimated in continental Portugal, which implies an increase of 58% over the expected deaths. When these values are split by gender, it is seen that women increase (79%), was considerably higher than that recorded for men (41%). The increment of mortality due to this heatwave was detected for all the 18 districts of the country, but its magnitude was significantly higher in the inner districts close to the Spanish border. When we split by gender all districts reveal significant mortality increments for women, while the impact in men's excess deaths is not significant over 3 districts. Several temperature derived indices were used and evaluated in their capacity to explain, at the regional level, the excessive mortality (ratio between observed and expected deaths) by gender. It is shown that the best relationship is found for the total exceedance of extreme days, an index combining the length of the heatwave and its intensity. Both variables hold a linear relationship with r = 0.79 for women and a poorer adjustment (r = 0.50) for men. Additionally, availability of mortality data split by age also allowed obtaining detailed information on the structure of the population in risk, namely by showing that statistically significant increments are concentrated in the last three age classes (45–64, 65–74 and 75 or more). The use of air conditioning systems in some Portuguese hospitals had a major impact on the decrease (up to 40%) in excessive mortality values. A finer approach is relevant for prevention strategies, since it allows to identify better the target population of any preventive strategy regional and national authorities may be interested to implement.  相似文献   

13.
脉冲变频电磁场对水中藻类的抑制及去除效能   总被引:6,自引:0,他引:6  
研究了脉冲变频电磁场对水华鱼腥藻的抑制及去除效果.结果显示,磁场对循环水样表现出很好的杀藻效果,水样在磁场中累积停留时间为6min时,杀藻率可以达到94%,累积停留时间为10min时,杀藻率可以达到96%.处理后的水样,藻细胞密度在120h内没有增加,生长受到抑制,经磁场处理的循环水样"磁记忆"时间可以达到120h.对于静置于磁场中的水样,处理1h后,藻的生长开始受到抑制.不同的处理方式会产生不同的效果,对于脉冲变频磁场,水以运动的形式通过磁场更有利于杀藻.  相似文献   

14.
邻苯二甲酸二(2-乙基己)酯(DEHP)是一种常用的增塑剂,在环境中广泛存在。本研究以马氏珠母贝胚胎为研究对象,揭示DEHP短期胁迫对胚胎发育的影响及胚胎DNA损伤。结果显示:DEHP对D型面盘幼虫的发育有显著影响,同一浓度组的死亡率与时间呈正相关。在(4~32)mg/L浓度范围内,不同胁迫时间段,幼虫的死亡率随染毒浓度升高而上升,表现出明显的剂量-效应关系,说明DEHP暴露能影响马氏珠母贝D型面盘幼虫的发育,并可能对其种群结构产生不利影响。DEHP胁迫还能对胚胎 DNA造成明显损伤,随着DEHP染毒浓度的增大,彗星尾长(TL)、尾矩(OTM)明显增加,尾部DNA含量(T-DNA)上升,3个指标表现出良好的相关性,DNA的损伤与暴露浓度间存在明显的剂量-效应关系。研究结果表明马氏珠母贝D型面盘幼虫的发育和形态学变化、胚胎细胞的DNA的损伤可以作为反映海洋环境中DEHP污染早期预警的敏感生物标志物。  相似文献   

15.
大气臭氧暴露对人群慢性阻塞性肺病(chronic obstructive pulmonary disease, COPD)的影响不断加剧.为评价大气臭氧暴露对COPD的不良影响,量化与大气臭氧暴露相关的COPD死亡负担以及相应的健康经济损失,本研究收集了2020年我国31个省(自治区、直辖市)臭氧浓度高峰季(4—9月)数据、社会经济及人口数据,基于已有研究中确立的大气臭氧暴露与COPD死亡的暴露-反应关系,以世界卫生组织2021年提出的臭氧浓度高峰季平均值(60μg/m3)为参考,分别估算我国大气臭氧暴露的COPD归因死亡人数和经济损失.结果表明:(1) 2020年我国大气臭氧暴露的COPD总死亡风险比为1.12[95%CI (95%置信区间)为1.00~1.21].(2) 2020年我国大气臭氧暴露的COPD归因死亡人数为10.12×104人(95%CI为0.00~17.49×104人).(3) 2020年我国大气臭氧暴露造成的COPD的健康经济损失为2 131×108元,占GDP的0.21%.研...  相似文献   

16.
For over 60 years, fishery scientists have been using the argument that nature creates surplus, and that the surplus can be used as justification to impose anthropogenic sources of mortality (power plants, fishing, pollution, etc.) on fish populations; otherwise, it is wasted. Surplus production is closely tied to the concept of compensation, a form of density-dependent mortality in which the mortality rate of a cohort is directly related to abundance of that cohort. Scientific arguments have been put forth in assessments of power plant impacts that compensation can at least partially offset impacts imposed by power plants. Although we cannot dismiss the existence of surplus production outright, since in some years environmental conditions are such that a surplus in reproductive effort may occur, we should be assessing the reproductive effort of fish populations in the context of the ecosystem in which they reside. In terms of addressing the risks of power plant mortality, we may be at a point in collection and analyses of biological data, coupled with a greater flexibility in managing power plant technology, to modulate the risks of power plant mortality on fish populations on a more-or-less real-time basis by taking into account environmental influences. For these reasons, assessments of power plant impacts should include analyses of predation forgone and production forgone.  相似文献   

17.
受污染地表水的生物毒性效应分析   总被引:1,自引:1,他引:0  
针对以非常规水源补水的受污染地表水的生态安全问题,文章以北京地区受污染河水为试验用水,利用多组生物效应试验(发光菌、大型蚤和仔鱼)进行急性生物毒性检测,并与污水厂二级出水和再生水厂出水水质进行比较.结果表明:受污染地表水在浓缩倍数达50倍时,发光细菌相对抑制率达到50%以上,大型蚤和仔鱼的急性毒性试验死亡率均达到100...  相似文献   

18.
The 1990 amendments to the US Clean Air Act (CAA) encouraged the growth of mountaintop removal (MTR) coal mining in Central Appalachia. This study tests the hypothesis that the amendments had unintended impacts on increasing mortality rates for populations living in these mining areas. We used a panel design to examine adjusted mortality rates for three groups (all-cause, respiratory cancer, and non-cancer respiratory disease) between 1968 and 2014 in 404 counties stratified by MTR and Appalachian/non-Appalachian status. The results showed significant interactions between MTR status and post-CAA period for all three mortality groups. These differences persisted after control for time, age, smoking rates, poverty, obesity, and physician supply. The MTR region in the post-CAA years experienced an excess of approximately 1200 adjusted deaths per year. Although the CAA has benefits, energy policies have in general focused on the combustion portion of the fossil fuel cycle. Other components of fossil fuel production (e.g. extraction, transport, and processing) should be considered in the comprehensive development of sustainable energy policy.  相似文献   

19.
PM2.5是对空气中直径小于或等于2.5μm的固体颗粒或液滴的总称,又叫细颗粒物或入肺颗粒物。为解除目前我国大部分地区灰霾天气的困扰并探索其形成原因,文章主要综述了PM2.5的形成、危害及防治措施。通常用PM2.5来表示每立方米空气中这种颗粒的含量,该值越高,就代表空气污染越严重。PM2.5对人体危害极大,其大小与相应疾病的发病率,死亡率成正比。空气中的PM2.5的浓度可以通过重量法等进行测量。以微生物过滤为辅助,降低工厂,汽车的废气,尾气排放从而减少PM2.5的污染,也可以增加生活环境中净化空气的绿色植被,利用静电除尘的方法来改善空气质量。  相似文献   

20.
Fetal supraventricular tachycardia (SVT) can be successfully treated transplacentally, but in cases where fetal hydrops develops there is considerable morbidity and mortality. The present study was carried out to establish whether the introduction of flecainide altered obstetric management and fetal outcome. A retrospective analysis took place of 51 singleton pregnancies which were referred to the division of prenatal diagnosis because of fetal tachycardia between 1982 and 1993. SVT was documented in 50 out of 51 fetuses, one of which displayed a combination of extensive rhabdomyomas and severe hydrops and died shortly after referral. In the other fetus ventricular tachycardia was diagnosed. Of the remaining 49 fetuses, 14 did not receive any prenatal treatment, but nine needed postnatal treatment. Transplacental treatment of SVT took place in 35 fetuses, of which 22 presented without hydrops and 13 with hydrops. These subsets differed significantly with respect to restoration of normal sinus rhythm (73% vs. 30%; p<0.001) and mortality (0% vs. 46%; p<0.001). Digoxin was effective in restoring sinus rhythm in 55 per cent of the non-hydropic fetuses but in only eight per cent of the hydropic fetuses. Flecainide was effective in restoring sinus rhythm in all non-hydropic fetuses where digoxin treatment failed, and in 43 per cent of hydropic fetuses. Administration of flecainide resulted in a significantly reduced mortality (p<0.001) compared with digoxin treatment. No adverse effects were seen. Postnatal anti-arrhythmic treatment was necessary in 23 infants. Treatment could be withdrawn within one year in all cases but one.  相似文献   

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