The Brown Trout Population at Loch Fleet Eight Years After Liming

Abstract

At the start of the Loch Fleet Project in 1984, the Loch and the upper 7 km of its efferent stream were found to be devoid of trout (Salmo trutta) as a result of acidification. Following the liming treatments applied to the catchment, from 1986 the formerly toxic water quality conditions (pH ～ 4.5, calcium ～ 1 mgl^?1, elevated aluminium and heavy metal levels) were eliminated, and trout were reintroduced on two occasions, in 1987 and 1988. A total of 520 fish were stocked, at a combined density equivalent to 5.5 kg ha^?1. Surveys of the loch and stream populations were carried out annually until 1993 to monitor their development, using a range of techniques, including electrofishing, gill-netting, seine-netting, spawner trapping and mark-release recapture methods. Length and scale- analysis were used to investigate fish growth.

The trout population in Loch Fleet expanded rapidly as a result of natural spawning in the loch's main feeder stream, augmented by the use of an artificial spawning bed which was constructed at the loch outlet in 1990. in mid-1983 the stock density, estimated by mark-recapture census methods, had increased to 24.9 kg ha^?1. Poor recruitment in the years 1991–93, however, reduced the rate of expansion and resulted in a population comprising mainly older individuals. the poor recruitment in these years was not fully explained but was not caused by water quality and was most likely a result of fry washout by spring spates.

Fish growth rates were high initially and were estimated on the basis of the Elliott trout growth model to be optimal for the prevailing water temperature regime of the loch. By 1991, growth rates had fallen, probably as a result of competition for food, but showed signs of recovery towards the end of the study period in 1993, following the period of lower population densities of young fish.

Trout rapidly repopulated the loch's outlet stream after 1987 but have remained sparse and have shown no signs of spawning within most of the stream. Water analyses have shown that the liming of the Loch Fleet catchment has minimal impact on downstream waters when flows are high, so that potentially toxic acid episodes have not been prevented.     

Bioaccumulation and toxic effects of copper on growth and oxygen consumption by the postlarvae of Penaeus indicus

The aim of this study was to assess the toxic impact of copper on postlarvae (PL) of the penaeid shrimp Penaeus indicus. Tolerance, growth, oxygen consumption and metal accumulation were investigated in these PL on exposure to copper. Tolerance studies were conducted for 96 h to assess the tolerance limits of P. indicus PL exposed to different concentrations of copper using static renewal bioassay tests. Using the Probit method, the regression equation was calculated as Y=0.4899+2.3562 X, with a correlation coefficient of 0.9707. The 96 h LC₅₀ was 0.8204 ppm. The effect of sublethal (one-fifth of 96 h LC₅₀) copper on PL for short- and long-term exposures revealed a significant (p<0.05) decrease in the rate of oxygen consumption, metabolic rate, mean length, wet and dry weight of the exposed PL over their respective controls which can be attributed to a gradual and time-dependent accumulation of the metal, as noticed in the exposed PL through accumulation studies. Overall, the data suggest that on chronic exposure even sublethal concentrations of copper can reduce the metabolic rate and growth in P. indicus PL. This is perhaps the first attempt to use the wild P. indicus PL as a bioindicator of copper toxicity.     

The Influence of Anthropogenic Contamination On Metals Release From Coastal Sediment Suspensions with Aerated Sea Water

The zinc, cadmium, copper and lead release from the uncontaminated and contaminated coastal sediments with aerated sea water was studied. the metals transfer to the dissolved forms was monitored during one-two months by differential pulse anodic voltammetry (DPASV). the sediments with different initial degree of contamination were sampled in the Peter the Great Bay, Sea of Japan around Vladivostok-the biggest city in Russian Far East. Sediment contamination by metals led to increased release to solution of zinc due to sulphide oxidation and cadmium on account of organic matter decomposition. the copper behaviour was complicated by strong binding with organic matter and enhancements of copper release can only be seen in sediment with a low organic matter content. Significant lead transfer to dissolved forms was not observed regardless of sediment contamination. the temperature affected the release of cadmium and copper through enhanced organic matter destruction. the dissolved metal fluxes from the sediment transformation are compared with metal fluxes towards bottom. Such comparisons show that second contamination by dissolved metals of the studied coastal environment may be important for cadmium only.     

经济增长质量与能源效率是一致的吗?

论文从全社会节能的角度提出全社会能源效率的概念,构建了经济增长质量指标体系,并基于1997—2007 年中国30 个省份的面板数据,采用Malmquist DEA方法测算了广义技术进步指数并进行分解,然后运用面板方法分析了经济增长质量与能源效率的作用机制,研究结果表明经济增长质量与能源效率是不完全一致的,具体表现为:改善环境质量与提高能源效率是一致的,技术进步与产业结构升级能够促进能源效率,但出口比重的增加和生活水平的提高会抑制能源效率的改进。技术进步、技术效率、纯技术效率和规模效率对全社会能源效率有正向影响,技术效率的作用大于技术进步,纯技术效率和规模效率的下降削弱了技术进步的正向作用。     

Exploring long-term land cover changes in an urban region of southern Europe

This paper addresses two important issues for large Mediterranean city regions: the differential impact of compact urban ‘growth’ and low-density ‘sprawl’ on land cover changes (LCCs), and their final effect on changing land cover relationships (LCRs). The urban expansion of Rome (Italy) during the last 50 years and the related LCCs were investigated as a paradigmatic example of compact versus dispersed urban development. LCCs were assessed over 5 years (1960, 1974, 1990, 2000, 2006) by analysing diachronically the distribution of 12 land cover categories derived from digital land cover maps covering the entire Nuts-3 prefecture of Rome (5353 km²). LCRs were studied using multi-way data analysis. LCCs were found to have relative differences during ‘growth’ (1960–1990) and ‘sprawl’ (1990–2006) phases. Conversion to urban land uses concentrated in the 1960s and 1970s at the urban fringe, while expanding progressively far from the city in the 1990s and 2000s. During the ‘growth’ phase, the land cover classes with the highest probability of being converted to urban uses were arable lands, annual crops, vineyards and pastures. During the ‘sprawl’ phase, olive groves, orchards and forest surfaces also decreased due to the development of low-density built-up areas and infrastructure. Planning suggestions aimed at mitigating the alteration of the rural landscape through sprawl conditions are discussed.     

离子液体氯化1-辛基-3-甲基咪唑对酵母细胞增殖生长和细胞膜通透性的影响

为探讨咪唑类离子液体氯化1-辛基-3-甲基咪唑([C₈mim][Cl])对酵母细胞的增殖生长和细胞膜通透性的影响,以不同浓度的[C₈mim][Cl]处理酵母细胞,研究离子液体对酵母细胞增殖和菌落形成的影响,通过测定酵母细胞外液蛋白质和核酸的含量,判断膜通透性的大小和[C₈mim][Cl]对细胞膜性结构的损伤。结果显示,0.1 mmol·L^-1的[C₈mim][Cl]延长了酵母细胞到达对数生长期的时间,在6～9 h之间对酵母细胞的增殖存在明显的抑制作用。1 mmol·L^-1的[C₈mim][Cl]使酵母细胞增殖不能到达对数生长期,对酵母细胞的增殖一直具有较强的抑制作用。随着离子液体浓度的增加,小菌落的数量增多。当平板内[C₈mim][Cl]浓度达到10 mmol·L^-1时,完全抑制了菌落的形成。[C₈mim][Cl]处理酵母细胞后,细胞外液中OD₂₈₀、OD₂₆₀的值显著升高。研究表明,细胞膜等膜性结构通透性的增加是离子液体[C₈mim][Cl]抑制酵母细胞增殖生长的原因之一。     

Protected areas as frontiers for human migration

Causes of human population growth near protected areas have been much debated. We conducted 821 interviews in 16 villages around Budongo Forest Reserve, Masindi district, Uganda, to explore the causes of human migration to protected areas and to identify differences in forest use between migrant and nonmigrant communities. We asked subjects for information about birthplace, migration, household assets, household activities, and forest use. Interview subjects were categorized as nonmigrants (born in one of the interview villages), socioeconomic migrants (chose to emigrate for economic or social reasons) from within Masindi district (i.e., local migrants) and from outside the Masindi district (i.e., regional migrants), or forced migrants (i.e., refugees or internally displaced individuals who emigrated as a result of conflict, human rights abuses, or natural disaster). Only 198 respondents were born in interview villages, indicating high rates of migration between 1998 and 2008. Migrants were drawn to Budongo Forest because they thought land was available (268 individuals) or had family in the area (161 individuals). A greater number of regional migrants settled in villages near Lake Albert than did forced and local migrants. Migration category was also associated with differences in sources of livelihood. Of forced migrants 40.5% earned wages through labor, whereas 25.5% of local and 14.5% of regional migrants engaged in wage labor. Migrant groups appeared to have different effects on the environment. Of respondents that hunted, 72.7% were regional migrants. Principal component analyses indicated households of regional migrants were more likely to be associated with deforestation. Our results revealed gaps in current models of human population growth around protected areas. By highlighting the importance of social networks and livelihood choices, our results contribute to a more nuanced understanding of causes of migration and of the environmental effects of different migrant groups.     

林下和撂荒地生境紫茎泽兰幼苗的生长特征及其种内竞争形态反应

比较研究了林下和撂荒地生境有无竞争条件下紫茎泽兰（Ageratina adenophora（Sprengel））幼苗的生长特征、生长速率、生物量和种内竞争的形态反应。结果表明：（1）2类生境条件下紫茎泽兰植株幼苗形态特征基本一致,无竞争条件下紫茎泽兰幼苗根长和叶片数明显高于在竞争条件下对应指标值;（2）同类生境中,在无竞争条件下紫茎泽兰幼苗的生长速率、生物量积累显著比在竞争条件下的高;（3）不同生境中,撂荒地生境紫茎泽兰幼苗生物量显著高于林下生境的值,在无竞争条件下,林下生境紫茎泽兰幼苗生长速率比撂荒地生境的高,而在竞争条件下反之;（4）林下和撂荒地生境紫茎泽兰幼苗植株竞争强度差异不显著,但在林下生境其地上部分的竞争强度显著大于其在撂荒地生境的值,而根的竞争强度相反。可见,紫茎泽兰幼苗在种群建立的过程中具有不同的生态适应性和形态反应,这可能是其能成功入侵不同生境的一种重要生理生态策略。     

零价纳米铁对大肠杆菌的毒性效应

以大肠杆菌为研究对象,通过检测尺寸为20 nm的零价纳米铁暴露下大肠杆菌形貌、生长曲线和细胞内酶活性的变化,研究了零价纳米铁对大肠杆菌的毒性效应,并探讨了其可能的毒性机制.用透射电镜(TEM)观察零价纳米铁与大肠杆菌(JM109)接触后细胞的形态变化;用0、112、560和1 120 mg·L-1的零价纳米铁染毒大肠杆...     

内蒙古经济发展与环境污染之间关系的检验

利用内蒙古1986-2009年间的6类环境污染指标和人均GDP数据,基于VAR计量技术,通过变量平稳性和协整检验,Granger因果检验和脉冲响应分析对经济增长与环境污染的关系及其动态性进行了实证研究。结果显示:①当内蒙古粉尘排放量增长率、 工业固体废弃物产生量增长率、 工业二氧化硫排放量增长率和工业烟尘排放量增长率各增加1%时,人均GDP分别降低0.068%、 0.411%、 0.380%以及0.418%;当工业废气排放量增长率和工业废水排放量增长率分别增加1%时,人均GDP分别上升1.305%和1.601%。②人均GDP变化是工业固体废弃物产生量和工业废气排放量变化的Granger原因,但各污染物排放并不是人均GDP变化的Granger原因,这与研究期间内蒙古处于工业化尤其是工业中的采矿业发达的事实吻合。③人均GDP增长率对来自环境变量增长率的冲击影响其响应表现为在第1期均为0,从长期响应来看,给粉尘和废水排放增长率一个正的冲击,人均GDP增长率的响应为持续的降低;对来自废气排放增长率冲击响应函数图在前4期表现出"增长-降低-增长"的趋势,而在后6期表现为缓缓下降;对来自固体废弃物产生量增长率和二氧化硫排放量增长率冲击响应不明显;对来自烟尘排放量增长率的冲击其响应在第2期达到最大值,随后也呈递减趋势。④从方差分析的结果看,不考虑GDP自身的贡献率,内蒙古环境污染指标排放增长率对人均GDP增长率贡献率较小,而在不考虑内蒙古各个环境污染指标排放增长率自身的贡献率的情况下,内蒙古人均GDP增长率对环境污染指标排放的增长率的贡献较高。这进一步说明了内蒙古环境各污染因子排放量的增多并没有大幅度促进人均GDP的增长,但是人均GDP增长却带动了工业污染物排放的增长。