Ökologische Bewertung von Tieflandbächen des Ladberger Mühlenbach-Systems im Norddeutschen Tiefland, basierend auf der Standorttypie der Trichopterenbiozönosen

In the last few years ecological evaluation of lowland freshwaters was controversely discussed. Due to the fact that most basic information of assessment systems derived from upland streams, the results could not be applied to the lowland situations. Additionally, it is not sufficient for an integral freshwater evaluation only to focus on the stream to show degradation in the tight coupling of running waters and their adjacent landscape. In this study we critically tested a new method, the Standorttypie-Index (STI), to assess lowland streams using caddis-fly communities.

During 1994 and 1996 we investigated the caddisfly community at 15 sampling sites of a river system in the “Westfälische Tieflandbucht” (Northrhine-Westphalia, Germany). As a result we found 72 species belonging to 16 families of the order Trichoptera. The calculation of the “Standorttypie-Index” is based on four defined ecological categories. Although the definitions were inaccurate, each species was classified into one category. In view of stream regulation and streamwidth, we calculated for all study sites the STI of the immature stages, the adults and a combined total STI.

Although there is a correlation between the “Standorttypie-Index” and the state of degradation of the study sites, the separate analysis of larval and adult communities showed that the results easily lead to misinterpretation. The STI of adults devalues the combined total STI of regulated as well as natural study sites. As a consequence, until now it is not possible to evaluate the state of degradation in the coupling of the stream and the adjacent landscape using the STI of the caddis-fly community.     

Parasite communities in Boops boops (L.) (Sparidae) after the Prestige oil-spill: detectable alterations

Environmental pollution affects parasite populations and communities, both directly and through effects on intermediate and final hosts. In this work, we present a comparative study on the structure and composition of metazoan parasite communities in the bogue, Boops boops, from two localities (Galician coast, Spain) affected by the Prestige oil-spill (POS). We focus on the distribution of both individual parasite species and larger functional groupings by using both univariate and multivariate analyses. Our results indicate directional trends in community composition that might be related to the Prestige oil-spill disturbance of the natural coastal communities off Galicia. Endoparasite communities in B. boops reflected a notable change in the composition and abundance of the benthic fauna in the localities studied post-spill probably due to organic enrichment after the POS.     

Belastungscharakterisierung von Flußabschnitten der Saale und der Weißen Elster mittels Faktorenanalyse

Loads along a river can be characterized and differentiated with the aid of the factor analysis after suitable normalization. The factor analysis as a multivariate-statistical evaluation allows the finding of sources of contamination, their objective assessment and quantification in relation to the conditions found in the river. The analysis of the river Saale shows a geogenic factor all the year round, which is composed of hardness elements, a seasonally fluctuating factor that can be represented in summer only, by which especially the processes of nitrogen conversion are recorded (nitrate, nitrite, organic load). An “industrial factor” contains the heavy metals Cu, Cr and Zn as well as temperature and sulphate, whereas cadmium, suspended matter and chloride result from municipal wastewaters.     

Zum Leistungsvermögen makroporöser Adsorberpolymere bei der Elimination organischer Mikroverunreinigungen

In laboratory experiments the adsorption of eleven different organic substances in water is individually tested in the range of concentration of 0.2… 5.0 mg/l on EP 60 and EP 61 (styrene-divinylbenzene, non-polar) and EP 62 and Y 59 (acrylic-acid-ester-divinylbenzene, polar). In batch experiments the elimination at 1… 2 g/l adsorber quantity was 35… 80%, strongly dissociated anionic substances as benzoic acid being adsorbed only to a low degree and weakly cationic and undissociated substances being adsorbed well. Within a homologous series adsorption increases with the molar mass until the pore diameter will become too small for the taking up of substances. Under dynamic conditions (filtration technology) an elimination of 90… 100% can be expected. As a whole, the adsorption on activated carbon was better in all cases than the adsorption on the polymers. The desorption for the regeneration of the polymers is the more difficult the better the substance contained is adsorbed. By repeated loading and regeneration only a slight influence on the adsorption and desorption of a substance was found.     

Qualitätsprobleme bei der Gewinnung von uferfiltriertem Grundwasser in Ungarn

Summary: In Hungary a large proportion of the drinking-water demand is met by bank filtration. Especially the middle section of the Danube stretch is used for drinking-water supply, also for the capital Budapest (310 · 10⁶ m³/a). The considerable pollutant load imported, anyhow, is increased by several Hungarian sources of contamination. The Danube has such a high self purifying capacity that, among other things, the annual COD-Mn load by the city of Budapest amounting to 140,000 t is degraded to such a level that the export of organic pollutants in the Danube from Hungary is not greater than the import. Heavy metals get into the bank filtrate through organic complexing agents. Also organochlorine compounds and their precursors were quantitatively determined. In Budapest water is treated with ozone, activated carbon and open high-rate filtration.     

Trends und Verteilungsmuster in der Schadstoffbelastung von Sedimenten aus östlichen Bundeswasserstraßen

Trends and Patterns in the Contamination of Sediments from Federal Waterways in Eastern Germany The following study presents a concept for a sediment pollution cadastre and the results of systematic investigations of sediment contamination for eight toxic heavy metals and arsenic, as well as for eight classes of organic priority pollutants in all together 21 reaches in the Elbe and Oder waterway systems. Based on data from the years 1991 to 1995; multivariate statistical evaluations were carried out to identify local and temporal trends in the overall contamination. It was possible to differentiate between more non-point and point sources of sediment contamination. Because of the closure of substantial parts of the industry in Eastern Germany and by common sanitation efforts of both the German and the Czech sides since 1990, the situation in the Elbe river system with respect to the heavy metals has improved markedly. For the Oder river system, a comparable trend does not exist yet, and the sediment contamination by heavy metals is stagnant there. As a consequence, the pollution situation in both German parts of the rivers has become similar except for mercury and arsenic. Regarding organic pollutants, the picture is quite different. With the exception of PAHs, Oder sediments are contaminated by organics only to a lower extent and compare better with the ones from unpolluted waters found in parts of Brandenburg and Mecklenburg-Western Pomerania than with those of rivers Elbe, Mulde, and Saale with its tributaries. On the one hand, organic pollution generally also decreased since 1991 in these rivers. On the other hand, due to continuing inputs from plants in the Czech Republic and from old contaminated sites, both in Czechia and Germany, a decreasing trend is not significant or cannot be found at all for such pollutants as HCB, PCBs, or PAHs. The general trends are discussed in detail, e.g., by comparison with quality targets for sediments and suspended matter, and illustrated at the example of individual contaminants being typical for the overall situation.     

Macroinvertebrate assemblages in conditions of low-discharge streams of the Cerová vrchovina highland in Slovakia

Macroinvertebrate communities at 16 sites in Cerová vrchovina highland were sampled in 2000–2001 to analyze the influence of environmental factors on community structure with emphasis on Ephemeroptera, Plecoptera and Trichoptera (EPT). The extreme hydrological conditions of this area determine the macroinvertebrate community structure. Totally, 16 Ephemeroptera, 8 Plecoptera and 36 Trichoptera taxa were found. Predators of the families Perlidae, Perlodidae and Chloroperlidae (Plecoptera) were absent. The record of Protonemura aestiva is the second one in Slovakia. Ephemeroptera were represented mainly by rheophilous taxa. A rare lowland species Baetis tracheatus was found, known previously just from West Slovakia. Trichoptera were mainly represented by submontane rheophilous taxa. Species preferring low currents or backwaters from the family Limnephilidae were also recorded. Altitude and dissolved oxygen content were found to be the most important environmental variables determining the EPT community structure. Six types of streams were distinguished by the results of multivariate analysis, taxonomic composition and metric values. They belong to two main types: (1) EPT communities of the natural streams and (2) EPT communities of disturbed streams, where two types of stressor were identified–organic pollution and low discharge. A similarity between EPT communities of organically polluted streams and streams with very low flow was discovered. Values of biotic indices decreased in summer. The most diversified communities were found in the spring during higher water levels and better oxygen conditions.     

Wasserlösliche Huminstoffe in Wässern einiger Kiestagebaue der DDR

After an explanation of the complex composition of the system of humic substances, some gravel deposits are described from whose open-pit boundaries there were taken water samples, their content of components of humic matter having been determined. Since spectroscopic analysis techniques yield spectra which are difficult to analyse and have a relatively low detection sensitivity, an indirect polarographic method was applied by which water-soluble humic substances can be determined very selectively down to a lower limit of 5 μg/1. Thus, enrichment in water or in adsorbing columns is not required. From the results found there are derived several statements concerning the occurrence of humic substances and fulvic acids in waters and conclusions about the possible influence on the hardening of concrete are given.     

Fischökologische Leitbilder fünf ausgewählter Salzkammergutseen

Ecological base line states for fish communities are necessary for the evaluation of ecological integrity. In Austria the fish communities of all the larger lakes are strongly influenced by human activities, like commercial fisheries, fish stocking, eutrophication or shore line degradation, and therefore these baseline states can not be developed by comparison with a natural, undisturbed lake. We developed ecological baseline states for the fish communities of the lakes Hallstättersee, Traunsee, Mondsee, Irrsee and Wallersee by reconstructing the native fish communities of these lakes from historical documents (from between 1500 to 1940). Then we classified the potential fish species of these lakes according to their ecological requirements. Finally we developed the base line states with 16 different ecological factors similar to the factors used for the ecological integrity assessment procedure for streams.

The process of reconstructing the fish communities and some advantages and disadvantages of the base line states for fish communities are discussed.     

Structure and taxonomic composition of free-living nematode and macrofaunal assemblages in a eutrophic subtropical harbour,Hong Kong

The spatial and seasonal taxonomic composition patterns of macrofauna and nematodes in a eutrophic subtropical harbour, previously suffered from sewage pollution, were studied in relation to a number of sediment parameters. In the polluted, inner-harbour area, levels of organic contents and heavy metals were high, whereas species number, abundance and diversity of nematodes and macrofauna were the lowest in comparison to the cleaner, outer-harbour area. Different taxonomic composition patterns of nematodes and macrofaunal assemblages were found between inner-harbour and outer-harbour area, which was highly correlated with sediment nutrient levels. Different responses of macrofaunal and nematode communities to sewage pollution suggested that macrofauna might be more tolerant than nematodes to eutrophic conditions due to their ability to modify the sediment. The present findings indicated the usefulness of studying both nematode and macrofaunal communities, in order to reveal different aspects of the benthic ecosystems in response to organic enrichment.     

Application of Hydrophobic Interaction Chromatography (HIC) in Water Analysis Anwendung der Hydrophobizitätschromatographie (HIC) in der Wasseranalytik

Dissolved high molecular weight organic substances, like humic substances, can be characterized with regard to their molecular weight distribution using gel filtration chromatography (GFC). In addition, the adsorption properties, for example on activated carbon, can be described, if the substances are separated by hydrophobic interaction chromatography (HIC) in different fractions using a chromatographic column with a hydrophobic matrix. The retention time (Rt) of single chemical substances in this column can be used to characterize the hydrophobicity or hydrophility of each compound as well as of the high molecular weight organic matter. The hydrophobic interaction between the matrix of the column and the dissolved chemical compounds also depends on the hydrophobicity of the gel and the composition of the eluent. Relations between retention times, log P-coefficients (octanol/water partition) and K-values of isotherms on activated carbon (Freundlich equation) were found.     

Zur Modellierung der Adsorption von Mehrkomponentensystemen

Many dissolved organic compounds in waters and wastewaters can be effectively removed by adsorption processes. The design of such processes requires the modelling of adsorption equilibria in multi-solute systems. In this paper a review on the most useful equilibrium models for multicomponent systems of known and unknown composition is presented.     

Effects of industrial outfalls on tropical macrobenthic sediment communities in Reunion Island (Southwest Indian Ocean)

Temporal changes in the composition of soft bottom macrobenthic assemblages at Reunion Island (Southwest Indian Ocean) were studied in the context of a long-term environmental monitoring programme studying the impacts of effluents of industrial sugar cane refineries that are transferred to shallow and deep coastal environments by different pathways: surface discharge and deep underground injection. Seven stations (between 20 and 160 m depth) were surveyed between 1994 and 2003 on the industrial zone. One additional station was surveyed on a reference site. Spatio-temporal changes in the composition of macrobenthic communities were assessed using several diversity indices, ABC curves, MDS and associated ANOSIM tests and biotic indices. Among the 171 taxa recorded, polychaetes were dominant (89 species), followed by crustaceans and molluscs. The analysis of spatial changes in the composition of macrobenthos showed the existence of distinct benthic communities along the depth gradient. Temporal changes in macrobenthos composition were most prominent at the shallowest station. They mainly corresponded to the decline of several initially dominant taxa and the increase of the Eunicid polychaete Diopatra cuprea. This station further showed increasing macrofaunal abundance, biomass and sediment organic content over time, concomitant with decreasing sediment grain sizes. In deeper environments, temporal changes were much smaller. Macrofaunal abundance and species richness increased progressively, suggesting a moderate impact on benthic ecosystems resulting from slight enrichments due to effluents rich in organic matter. Our results highlight an original response to disturbance pattern involving opportunistic Eunicidae species (D. cuprea) not previously described. Moreover, they allow for the comparison of the impact on macrofauna caused by industrial effluents exported by two distinct and different pathways in a tropical coastal high-energy marine environment.     

Kohlenstoffumsatz durch Respiration in der Ilm (Thüringen,Deutschland)

Carbon Turnover by Respiration in the River Ilm (Thuringia, Germany) In the river Ilm, the organic carbon content of water and sediments was analyzed inclusively the C turnover by CO₂-respiration with IR-measurement. A comparison of the unpolluted rhithral (headwater) with the polluted epipotamal (lower course) gives downstream an increase of DOC and CO₂-respiration of 50...100 mg/(m³ · h) C. In the headwater region, the respiration of the sediments is dominant, in the underflow the respiration of the water. Permeable sand and gravel beds are important for the degradation of the organic load. The sediments of the river are covered with a biofilm of 1...2 g/m² C_org. A turnover of the C_org. content from 20...400 days is calculated by the respiration measurements.     

Abschätzung der Eignung einer molekularbiologischen Methode zur Charakterisierung der Grundwasserbiozönose

Assessing the Suitability of a Molecularbiological Method To Characterise the Microbial Populations in Groundwater A molecularbiological technique was used to characterise the bacterial community structure of groundwater habitats. This method consists of the isolation of bacterial DNA from the samples, amplification of 16S rDNA by PCR (polymerase chain reaction), and separation of the amplified DNA by DGGE (denaturing gradient gel electrophoresis). By using more specific primer combinations in the PCR instead of universal eubacterial primers, also groups of microorganisms (Proteobacteria, sulfate reducer, Archaea) were determined. The resulting DGGE patterns that reflect the microbial diversity are compared and differences or similarities evaluated. In the present studies, groundwater from different sites (bank filtrate, artificially recharged groundwater, and natural groundwater) and with changing redox milieus (aerobic, anaerobic) were investigated as well as the solid aquifer material. Besides, samples were taken from the different stages of artificial groundwater recharge, i.e., from surface water to the drain tile. Samples from groundwater derived from sites with different hydrogeochemical or hydrological conditions like bank filtrate and recharged groundwater revealed great differences in DGGE patterns indicating a characteristic species composition in these habitats, while samples taken at different times from the same groundwater showed only small seasonal variations. Clearly different patterns were also found for groundwater and the adjacent solid material as well as for anaerobic and aerobic groundwaters. Looking at artificial groundwater recharge, almost identical patterns were found in raw water and samples from gravel and sand filtration. DGGE patterns from the resulting groundwater indicated a total change in community structure during underground passage. By using group specific primers, Desulfovibrionaceae, Desulfobacteriaceae, and Archaea could be detected in anaerobic groundwaters.The molecularbiological approach described here gives an increasingly comprehensive and more precise picture of the microbial population of different environments. It is especially suitable to compare the community structure from different habitats or to analyse changes for example due to environmental stress at the same site.     

Zur ökonomischen Bedeutung der biologischen Selbstreinigung

In twelve flowing water (Q 1.04… 30.4 m³/s, 0.5… 1.2 m/s) the self-purification efficiency in 110 river sections (L 1.3… 26.4 km) is determined as the load difference in kg · d^?1 COD-Mn as well as in g · m^?3 referred to the daily passage. In the economical comparison, the self-purification efficiency is valued as substitution for wastewater treatment plants of the same capacity. At a mean specific capacity of 8.6 g · m^?3, the self-purification efficiency of the investigated waters is equivalent to economical values of 124 · 10³… 534 · 10³ M km^?1 investment costs, 11 · 10³… 80 · 10³ M · a^?1km^?1 operating costs and 5… 81 MWh · a^?1 km^?1 expenditure of energy. The specific capacity in g · m^?3 COD-Mn shows an exponential regression to the degree of saprobity (L = 0.015 · exp (1.7358 · S)). From this empirical model the limits of the self-purification capacity of aerobic waters by oxygen input can be detected: in respective examples more than 50% of the required oxygen input are due to weirs.     

Dissolved inorganic nutrients and organic substrates in the River Warnow (North-Eastern Germany) – Utilisation by bacterioplankton

After 1990, external loads of Central European rivers with inorganic nutrients (nitrogen and phosphorus) and organic material were reduced because of changed environmental laws. However, in the eutrophic lowland River Warnow, North-Eastern Germany, nitrate concentrations remained high with 35–185 μmol l⁻¹ without a significant decrease since 1992. In contrast, phosphate concentrations, varying between 0.3 and 5.2 μmol l⁻¹ during the growth season 2002, decreased significantly over the years. However, its concentrations still exceeded 1 μmol l⁻¹ regularly in the growth seasons. This load led to a substantial accumulation of organic matter additional to high terrestrial inputs. Despite the high organic load, the remineralising bacteria were mainly inactive in River Warnow. Therefore, the composition of the dissolved organic material, especially its bioavailability, were investigated during the growth season 2002 and discussed with other potential controlling factors. River Warnow carried a high load of dissolved organic carbon (14 mg l⁻¹), especially of humic substances (5.5 mg C l⁻¹). Bacterial abundance (12×10⁶ ml⁻¹) as well as production (1.7 μg C l⁻¹ h⁻¹) depended on temperature. During late spring and summer at constantly higher temperatures, bacterial production correlated positively to readily utilisable substrates and to humic compounds. Thus, the bacterial community in River Warnow may be well adapted or contain enough species using the available amino acids and carbohydrates as well as humic matter compounds. However, calculated from protozoan biomass, grazing may control bacterial biomass and perhaps community composition profoundly, what lead to the low percentages of active bacteria.     

Effects of the closure of a major sewage outfall on sublittoral, soft sediment benthic communities

The present study examines the benthos within western inner Swansea Bay (Wales, UK), for the period before, during and immediately after the cessation of a major, sewage discharge from Mumbles Head. There have been significant improvements in seawater quality and changes in the species composition of the benthic communities following the cessation of the sewage discharge. There has been an increase in the diversity of deposit feeders, especially the amphipods, and a decrease in the diversity of the filter feeders, especially the polychaetes. Changes are not attributable either to sediment organic matter content or to gross changes in sediment type, but are related to the significant reduction in suspended particulate organic material and sewage contaminants discharged to the Bay. A recovery model has been proposed to describe how soft sediment benthic communities in a shallow, sublittoral, high tidal energy environment respond to the abrupt cessation of a major sewage discharge.     

Molmasseverteilung der organischen Stoffe im Prager Trinkwasser

The water supply of Prague is based upon three different water resources: artesian groundwater and infiltrate of the Jizera river, water of the Vltava and Zelivka rivers. The processing techniques are different; consequently for the purpose of increasing capacity one has to search for the suitable raw water quality as well as for the optimum treatment process. An essential parameter for this is the contents of organic substances whose molar mass distribution is investigated by gel chromatography with the aid of Sephadex G-10, G-25 and G-50. With respect to the total load of organic matter the Jizera shows the lowest values, in the Vltava the C.O.D. values are the highest, in the Zelivka the organic carbon shows the highest values. 80% of the organic substances in water have molar masses below 700. By flocculation 60… 70% of the C.O.D.-Cr can be eliminated, the optimum removal of the high-molecular substances occurring at pH = 6 and with 50… 60 g/m³ aluminium sulphate.     

Veränderungen der Diatomeenflora der Werra unter dem Einfluß des Salzgehaltes

Under the influence of the wastewaters of the potash industry the Werra river shows considerably varying salt contents (0.47 … 28.2 g/l Cl^?, annual means 4.4 … 11.4 g/l Cl^?) in dependence on the hydrological situation. Between 1982 and 1988 a total of 112 taxa of diatoms were observed. Of special interest is the occurrence of Stauroneis constricta (EHRENBERG) CLEVE, which is new for the river Werra. Its spreading upstream was observed. Compared with earlier findings as well as within each annual cycle there are observed clear changes in the species present and in the colonization structures in dependence on the salt content. The close relations between the salt content and the diatom communities are truly expressed by the index of halobic organisms. Diversity indices of 1.048 … 3.259 as well as values of 0.074 … 0.817 for evenness verify the imbalance of the colonization, without, however, revealing a relation to the salt content, except for variations of concentration which may be too sudden.