Late Pleistocene–Holocene hydrologic changes in the interfluve areas of the central Ganga Plain, India

Abandoned channel belts, ponds and point bar deposits of palaeochannels in the interfluve regions of the central Ganga Plain suggest changes in the morphohydrologic conditions during the Latest Pleistocene–Holocene. Stratigraphy of these ponds comprises channel sand at the base overlain by shell-bearing clayey silt. The contact of the two facies marks the phase when channels converted into standing water bodies. Point bar deposits of some palaeochannels are overlain by oxidised aeolian sand, indicating that the channel abandonment possibly occurred due to the desiccation and aridity in the region.Optically stimulated luminescence (OSL) chronometry of the pond sediments suggests that the deposition of the basal channel sand started before 13 ka and continued up to 8 ka. The ponds formed around 8–6 ka when the channel activity ceased. Evidence from the point bar deposits also indicates that the fluvial activity in the region ended sometime during 7–5 ka. This was followed by aeolian aggradation. The present study thus suggests that the hydrologic conditions in the Gangetic plains, i.e. initiation of channels and their abandonment, formation of microgeomorphologic features such as ponds and their eventual siltation, were controlled largely by climatic changes (i.e. monsoon changes) supported by tectonic activity. For the past 2 ka, increasing human and related agricultural activity has substantially accentuated the natural siltation rate of ponds.     

The distribution of Potamothrix bavaricus (Oeschmann, 1913) (Oligochaeta) in anthropogenic freshwater habitats of an industrialised area (Upper Silesia, Poland)

The studies have revealed that Potamothrix bavaricus (Oeschmann, 1913), generally rare in Poland, is a common species in the benthic oligochaete fauna of different anthropogenic freshwater habitats in a heavily industrialised area of Poland. It was often found in habitats with significant salinity, a high total hardness and a large content of nutrients. The evident resistance to various pollutants enables the settlement of P. bavaricus in such habitats, which are unsuitable for other oligochaete species.     

Environmental recovery in Sydney Harbour,Nova Scotia: Evidence of natural and anthropogenic sediment capping

Contaminants were assessed in Sydney Harbour during baseline and three years of remediation of a former coking and steel facility. Concentrations of PAHs; PCBs; and lead measured in surface sediments indicate overall spatial distribution patterns of historical contaminants remains unchanged, although at much lower concentrations than previously reported due to natural sediment recovery. Recovery rates were in broad agreement with predicted concentrations; or in some cases lower, despite remediation at the Sydney Tar Ponds (STP) site. Contaminants showed little temporal variability, except for detection of significant increases in PAH concentrations during onset of remediation compared to baseline which represented a short term interruption in the overall long term natural recovery of sediments in Sydney Harbour. Recovery (via “capping”) was enhanced following recent harbour dredging activities where less contaminated outer harbour sediments were discharged into a confined disposal facility (CDF) required for a new container in the inner harbour.     

Fatty Acid Composition of Plankton and Bighead Carp (Aristichthys nobilis) in Freshwater Ponds

The community structure and fatty acid composition of plankton in broodstock ponds were studied at the Bishui Fisheries Company in the Liaoning Province, northeast China, between May and December 2002 and in March 2003. The Fatty acid analysis of bighead carp larvae and plankton in the fry pond occurred during June, July, and September 2002. The fatty acid composition of the plankton varied with seasonal changes in the community structure. When blue‐green algae dominated the broodstock ponds in spring and summer, the percentage of saturated fatty acids (SFA) (especially 16:0) was high. When diatoms and cryptophytes dominated in autumn and winter, the percentage of polyunsaturated fatty acids (PUFAs) (mainly n–3 PUFA) was high. Similarly, a high content of docosahexaenoic acid (DHA) occurred in autumn and winter when DHA‐rich copepods became an important group of zooplankton. In addition, environmental factors, especially water temperature, influenced the fatty acid composition of plankton. 16:0, DHA, and 18:1n–9 were dominant fatty acids of bighead carp larvae during ontogeny. 16:0, C18 unsaturated fatty acids, and eicosapentaenoic acid (EPA) were major fatty acids of plankton in the fry pond. Analysis of the relationship between the fatty acids of the larvae and those of plankton showed that the fatty acid profiles of the larvae did not always agree with those of plankton.     

CaCl2、NaHCO3和盐酸降pH的效果及其对水质的影响

本文于１９９８的８－１０月间选取山东省高青县赵店乡大芦湖养殖公司院内一口盐碱池塘的池水为实验用水,选用ＣａＣｌ２、ＮａＨＣＯ３和盐酸作试剂,进行了这三种试剂的降ｐＨ值实验。实验结果表明：ＮａＨＣＯ３有降ｐＨ效果须高浓度使用,但会使水体缓冲能力下降,不宜作为降ｐＨ的试剂。盐酸能迅速降低ｐＨ,但持续时间较短,适合急救时使用。２１９ｋｇ．ｈａ＾－１（１４．６ｋｇ／亩）的用量可降低ｐＨ１．５个单位。能长期     

Using digital mapping techniques to evaluate beneficiation potential in a coal ash pond

Coal-fired power plants produce energy and many by-products (unburned carbon, fly ash, and bottom ash) that are normally stored in permitted ponds and landfills. When the storage facility fills to capacity, it is necessary to haul material off-site for disposal, construct a new storage facility, or find a use for some of the material. Because certain criteria must be met to successfully beneficiate the ash, mapping the ash reserve provides data that shows where the most promising recovery sites will be.The University of Kentucky Center for Applied Energy Research (CAER) in conjunction with Western Kentucky Energy (WKE) and the US Department of Energy are constructing an ash beneficiation plant to recover high quality fuel and lightweight aggregate from the ash ponds at WKE's Coleman Station in Hawesville, KY. To determine the locations of the most productive areas, an extensive sampling and mapping project is underway. An amphibious ATV-mounted hydraulic drill has been employed to take core samples throughout the pond. These samples are then evaluated for particle size distribution, carbon content, chemical and leaching properties. With this information as well as each drill-hole's GPS coordinates and aerial photographs of the plant site, digital maps have been produced showing trends of deposition of material in the pond. Using a Geographical Information System to compile the data, the feasibility of removing ash for beneficial re-use can assessed.     

塘和湿地技术在面源污染控制中的应用组合模式探讨

塘和湿地技术是国内外最常见的生态工程技术,已被广泛应用于面源污染的控制和生态系统的修复等领域。本文综述了塘和湿地技术的技术原理、技术组合种类、应用组合模式以及在应用过程中存在的主要问题,以期为面源污染的控制提供借鉴和理论依据。     

Legacy contaminant bioaccumulation in rock crabs in Sydney Harbour during remediation of the Sydney Tar Ponds,Nova Scotia,Canada

Concentrations of PAHs, PCBs, metals and lipids in hepatopancreas of rock crabs (Cancer irroratus) were measured in Sydney Harbour (SH) for one year prior to remediation and three years of remediation of the Sydney Tar Ponds (STP), Nova Scotia. Low level concentrations of PCBs and metals were measured, although PAHs were mostly undetected. Metal concentrations showed little spatio-temporal variability, although highest concentrations of As, Cd and Cu were measured at reference stations furthest from the STP remediation site. Mercury concentrations were at least an order of magnitude lower than Canadian guidelines. Moderately elevated PCB concentrations were detected in crabs near Muggah Creek, but these were generally not higher than those measured during baseline. Despite remediation activities, current contaminant burdens measured in crabs were much lower than previously reported in other studies of crabs and lobster in industrial harbours in eastern Canada, due in part to natural recovery of SH sediments.     

Hydrogeomorphic types of glacially created kettle holes in North-East Germany

Kettle holes are glacially created, small, shallow, depressional wetlands collecting their water from internal or closed catchments in young moraine landscapes. Their water body is defined by having a maximum of 1 ha in extent. Mostly they undergo a wet-dry circle. In North-East Germany, kettle holes are widely spread, mostly on arable land. They are characterised by large differences in hydroperiod (HP), size, shape and edge steepness. They also have a high potential for both, geomorphic structural diversity and biological species diversity. However, kettle holes are subject to pollution, drainage and structural reduction that result from intensive land use practices.Although kettle holes in Germany are protected by law, protection strategies are not specific enough with respect to the variability of kettle holes, especially of HP. Therefore, the study objective was to characterise hydrogeomorphic (HGM) kettle hole types to create a basis for a decision support system with regard to the selection of the type dependent conservation and management measures.In three agricultural landscapes in North-East Germany, geomorphological and hydrological variables of 268 kettle holes (HP, shore overflow tendency, depth, area, form, shore width and slope) as well as those of their catchments (area, wetland to catchment area ratio, relief) were investigated from 1993 to 2003. By statistical analysis of datasets of 144 kettle holes, 10 HGM kettle hole types were defined. The basic types are “silted fen type” and “open-water type”. Basic subtypes of the latter type are “storage type”, “shore overflow type” and “puddle type”. Differences in spreading of kettle hole types in dependency on landscape relief were found.     

Litter breakdown of invasive alien plant species in a pond environment: Rapid decomposition of Solidago canadensis may alter resource dynamics

Alien plant invasions of riparian zones can trigger bottom-up effects on freshwater ecosystems through changes in leaf litter supply. Riparian zones of ponds are often invaded by alien species, and although these habitats are common, the effect of invasive alien species on ponds has rarely been studied. We performed a leaf litter experiment in a pond and compared within- and between-species variation in the breakdown rates of three native species (Alnus glutinosa, Phragmites australis and Typha angustifolia) and two aggressive alien invaders of riparian zones (Fallopia japonica and Solidago canadensis). The litter of S. canadensis decomposed faster than the litter of the other plants; more than 50 % of the S. canadensis biomass decomposed within a week. This contradicts the home-field advantage hypothesis, and we argue that the quality rather than the origin of litter might be the key factor driving breakdown rates. We also reported considerable intra-specific variation; old leaves (collected in spring after a partial aerial breakdown on stems) decomposed two to seven times slower than senescent leaves (collected in autumn just after abscission). The continuous seasonal supply of leaves of different quality into freshwaters may be disrupted by terrestrial invasions, especially if an invader forms monoculture stands and produces a highly palatable litter, as is the case with S. canadensis. This may fundamentally alter the resource dynamics in the pond environment through a rapid depletion of litter mass before the next litterfall.