Der Einsatz von Pflanzentests bei der Sedimentbewertung

Background and aim Aquatic organisms of the three trophic levels (producers, consumers, reducers) have been used for a long time for ecotoxicological assessments of water quality (HABAB 2000; HABAK 1999). In biotest systems that have become established standards, algae, daphnia, and luminescent bacteria as test organisms are often used so far. However, comparative studies have shown that algae are not sufficiently sensitive to all phytotoxic agents and thus cannot be the exclusive indicator organism of any toxic effects on autotrophic life. Moreover, the EU Water Framework Directive (EU-WFD 2000) sets macrobenthos, fish, phytoplankton, and macrophytes equally side by side as indicators of the status of waters. Nevertheless, biotest systems relying on higher plants have been rarely used in assessments of aquatic sediments so far. Against this background, the aquatic duckweed test (DIN EN ISO 20079) was developed and standardized, and a sediment contact test was developed with Myriophyllum aquaticum (Feiler et al. 2004). The latter was subject of a joint research project of the German Federal Ministry of Education and Research (BMBF-Verbundprojekt “SeKT”) that examined and compared several sediment contact tests (Feiler et al. 2005). Compared to tests with algae, a biotest using macrophytes has the advantage to be more representative of higher plants, since target organism and test organism are closer related in terms of evolutionary history. The present study demonstrates that the application of biotests with higher plants in analyses of contaminated sediments yields valuable results that may contribute to a concept for the integrative assessment of water quality.     

Einsatz der Hasse-Diagrammtechnik zur vergleichenden Bewertung von aquatischen Wirkungstests

An evaluation of pollutants depends on the ecotoxicological quality of the effect tests carried out. In this paper a compilation of aquatic tests is given independently on administration needs. The results are summarized in a table listing fields of application, importance for mathematical modelling and ecological relevance. The table includes 55 tests and 8 attributes characterizing each tests The interpretation of the results listed in this table is hardly feasible. An appropriate tool to rank the tests is the technique ofHasse-diagrams. Using this tool it can be deduced that no test fulfills all demands. There are six tests which are optimal with respect to applicability and mathematical modelling. However, they have no relevance for ecosystems. Only two tests are optimal with respect to ecotoxicology, There is still a gap between tests with a wide field of applications and those tests which are relevant with respect to ecotoxicology.     

Einsatz der Hassediagrammtechnik zum Vergleich von Bergbaubetrieben unter dem Aspekt der Nachhaltigkeit

Ziel und Hintergrund

Der Vergleich von Bergwerken unter dem Gesichtspunkt einer nachhaltigen Entwicklung erfordert die Berücksichtigung einer Vielzahl von Kriterien die gleichermaßen ökonomische, ökologische und soziale Aspekte berücksichtigen. Bergwerksbetreiber stehen bei ihren strategischen und operativen Entscheidungen vor der Schwierigkeit diese Kriterien angemessen zu berücksichtigen. Durch den Einsatz, der HDT wird die Komplexität der Entscheidungssituation reduziert. Sie unterstützt die Aufbereitung der verfügbaren Informationen und erleichtert so die Entscheidungsfindung.

Methodik

Das Ziel einer nachhaltigen Entwicklung im Bergbau kann durch den Einsatz von Indikatoren konkretisiert werden. Im Rahmen dieser Arbeit erfolgt ein Vergleich ausgewählter Bergwerke durch die Definition geeigneter Indikatoren, ihre numerische Belegung und durch ihre Verwendung in der HDT. Dabei werden verschiedene methodische Aspekte wie die Klassifizierung von Daten, deren Aggregierung und Gewichtung sowie die Einbeziehung von Expertenwissen dargestellt.

Ergebnisse

Am Beispiel ausgewählter Bergwerke wird gezeigt, dass eine Sortierung der Bergwerke anhand ihrer charakteristischen und als wesentlich erachteten Eigenschaften möglich ist. Durch den Einsatz der Hassediagrammtechnik wird die Komplexität der Entscheidungssituation reduziert. Es wird aber auch deutlich, dass mit diesem Instrument kein Verfahren vorliegt, dessen Einsatz automatisch zu einer eindeutigen Rangfolge führt. Es bleibt notwendig, die Anwendung der Hassediagrammtechnik in einen umfassen deren Entscheidungs-und Zielfindungsprozess zu integrieren.

Diskussion

Die Sortierung erfolgt bewertend, d.h. sie nutzt aus, dass charakteristischen Eigenschaften von Bergwerken inhärent eine Orientierung nach ?gut’ und ?schlecht’, zugeordnet werden kann. Es wird aber auch deutlich, dass mit diesem Instrument kein Verfahren vorliegt, dessen Einsatz, automatisch zu einer eindeutigen Rangfolge führt.

Schlussfolgerungen

Es bleibt notwendig, die Anwendung der Hassediagrammtechnik in einen umfassenderen Entscheidungs- und Zielfindungsprozess zu integrieren. Vorschläge zu einer Erweiterung der Hassediagrammtechnik werden formuliert.

Empfehlungen und Perspektiven

Die Hassediagrammtechnik versteht sich als eine Bewertungsmethodik, die das in der Nachhaltigkeits-/Bewertungsdiskussion so gefürchtete Vergleichen von ?Äpfeln mit Birnen’ vermeidet. Als relativ neue Methode, die sich als Alternative zu etablierten Bewertungsverfahren sieht, lässt sich weiterer Forschungsbedan ableiten.     

Einige neue Aspekte bei der Osmoregulation von Carcinus maenas

Employing specimens of the decapod crab Carcinus maenas L. from Kiel Bay in the Baltic Sea (～13 to 18‰S) and from Helgoland in the North Sea (～32‰S), comparative studies were made on the osmotic and sodium regulations. After a 3-day exposure to low salinities of 5 or 10‰, the internal medium of the crabs from the Baltic Sea has a greater freezing point depression and a higher sodium content, than that of the North Sea crabs. In normal sea water, the blood of North Sea specimens is slightly hyperosmotic; the blood of specimens from the Baltic Sea is nearly isosmotic to the surrounding medium. Individual cross adaptations to the different habitat salinities (2 to 3 weeks) result in a reduction of the osmotic differences in specimens of the two populations; the differences do not, however, completely disappear.     

Tonminerale als Katalysatoren bei der Umwandlung von organischen Verbindungen

Clay minerals show a variety of reactive properties, which make them used in industrial processes but are mostly neglected in soil science. In this overview these various properties of clay minerals are listed. Thereby it shall be pointed out, that these capabilities can also be of some importance in soils.     

Mineralölkohlenwasserstoffe im Boden bei der Sanierung von Altlasten

Various analyses and evaluative procedures are used to provide evidence of success using remediation procedures. Because of the lack of standardized procedures for soil assessment, general practice has unfortunately propagated the use of DIN standards for determining the level of similar parameters in water as well as for other heterogeneous matrices (e.g. in soil). A precise auditing of quality, however, has not been possible with this method, this procedure has even put the success of such a remediation into question. This article describes the problems of determining mineral hydrocarbon concentrations on soil as well as portraying the remediation of oil damages which has occurred on a site of a former waste oil redestillation facility [1, 2]. This procedure has been proved in practice and serves as a model because an adequately defined, standardized method (DIN standard) is lacking.     

Der einfluß der temperatur auf oocytenentwicklung und eiablage bei dem interstitiellen archiannelidenTrilobodrilus axi

The interstitial archiannelidTrilobodrilus axi Westheide 1967 inhabits sandy beaches of the Island of Sylt (North Sea). Spawning occurs from May to July, approximately. Development of oocytes and oviposition occur as soon as the water temperature has risen above 5 °C. In rearing experiments, the influence of temperature on maturation and release of gametes was studied in the female. Animals were collected in winter and reared at temperatures between 3° and 15°C. Within this range, development of oocytes and shedding of eggs were accelerated progressively with increasing test temperatures. Successful reproduction occurred only at temperatures above a critical level (between 3° and 6 °C). It was possible to shift the time of spawning by several months under experimental conditions; this suggests that, in the field, spawning is mainly controlled by temperature. The results indicate thatTrilobodrilus axi is probably a boreo-mediterranean species.     

Der einfluß von temperaturänderungen anf enzyme der fischmuskulatur. Versuche mit Rhodeus amarus

The enzyme activities estimated in the muscles of Rhodeus amarus (Bloch) may vary according to the kind of muscle, age and sex of the test individuals, as well as with the time of day, and the season. Oxygen consumption of individuals acclimated to different temperatures was tested at 22°C. At low adaptation temperatures no adaptation was found; at high adaptation temperatures, however, compensation could be ascertained. In view of the considerable fluctuation of the enzyme activities, estimated from individuals adapted to different temperatures, a relation to certain adaptation types, established by Precht (1961b, 1968), is hardly possible. During the first days following sudden or slow changes of adaptation temperature (increase or decrease) more or less marked fluctuations of enzyme activities were obtained. Later, however, in accordance with the proceeding adaptation, a new, labile balance was established. Temperature changes represent a physiological stress even within normal temperature ranges. This fact requires general attention in studies on biological processes. Disturbance of a newly established balance of enzyme activities can be obtained, when test fishes are exposed to high temperatures. This finding may be of importance in regard to the heat resistance of the animals.     

Toxizität und anreicherung von blei bei der miesmuschel Mytilus edulis im laborexperiment

In a laboratory experiment, conducted over 130 days, three batches of a total of 100 common mussels, Mytilus edulis, were maintained in media containing different lead concentrations. Two vessels served as controls. There was no acute injury to the mussels; but, over an extended period of time, a marked increase in mortality occurred which was related to the lead concentration in the medium. The median lethal time (LT₅₀) was computed to be 218 days for the control, 150 days with 0.5 mg Pb/l in the medium, 129 days with 1 mg/l, and 105 days with 5 mg/l. Quantitative analyses of the soft parts of M. edulis by flameless atomic-absorption-spectrophotometry revealed a distinct accumulation of lead. From a natural lead content of 8.4 μg Pb/g dry weight, the lead concentration increased to 12,840 μg/g at 0.5 mg/l, to 20,770 μg/g at 1 mg/l and to 39,830 μg/g at 5 mg/l. The ratio of the concentration of lead in the soft parts of M. edulis to the concentration in the medium remained in the same order of magnitude both under laboratory conditions using high lead concentrations and under in situ lead levels. Over a period of 130 days, lead uptake expressed as percentage of lead offered was 10.9% at 0.5 mg/l, 9.5% at 1 mg/l, and 3.4% at 5 mg/l, respectively.     

Systemalterung bei der Modellierung hemerober Geosysteme

Nowadays, computer models are one of the most important tools, not only for research concerning complex geosystems. Time-invariant approaches are primarily employed used [1]. Hemerobic geosystems are subject to an evolutionary process which, following a reduction in their significance, can develop in the direction of an oligohemerobic system. In the course of this development, values of important system parameters may alter significantly within only a few years. Consequently, model validation may only demonstrate a limited validity. Models for long term prognoses (more than 20 years) there fore lead to unusable results if the high momentum of hemerobic system parameters is not taken into consideration. Problems associated with this situation and a possible solution are presented with the aid of the modelling of the heavy metal transfer as observed in the sewage field-areas of Southern Berlin.     

Der Mikrowellenaufschluss als richtungsweisendes Totalaufschlussverfahren in der geochemischen Analytik

Wet-chemical total digestion sample preparation is one of the most important geochemical analytical methods. This method is commonly used to dissolve rock, soil and mineral samples in order to determine element composition in a wide concentration range, ranging from minute traces to ten fold percentages. In the past common practices using hydrofluoric acid, hydrochloric acid, nitric acid and perchloric acid at high temperatures and pressure have been applied. These methods are however somewhat disadvantageous with the potential danger incurred in using acids and the associated time factor. At the Bavarian Geological Survey, a microwave digestion procedure has been developed thereby yielding similar results comparable with classical methodologies. Having optimised measurement conditions and adjusting the methodology (ICP-AES and ICP-MS), the results derived from the pressure digestion method in accordance with Ruppert [1] were compared with those from the aforementioned microwave digestion method. A common water analytical statistical analysis and evaluation was applied. The outcome shows that under such analytical conditions (e.g. detection limits) comparable results have been derived.     

Ökologische bedeutung der schleimsekretion bei den planula-larven der hydroidengattung Eudendrium

Colonies of hydroid polyps of the genus Eudendrium Ehrenberg release planula larvae with a high yolk content. Immediately after hatching, they begin to excrete a slime rope. In the presence of water movements, larvae hatching simultaneously tend to join a trail of slime; in stagnant water, the larvae move down the rope separately. The planula larvae are unable to float. On the basis of aquarium observations, we suggest that slime ropes with larvae adhere to substrates in the vicinity of the mother colony; this prevents the larvae from being carried off too far into open waters. In view of the absence of medusae in Eudendrium, this response of the planula is interpreted as an adaptation to a purely sessile life cycle. Structure and distribution of the slime secretions are documented by means of light and electron-microscope photos.

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Ökologische bedeutung der schleimsekretion bei den planula-larven der hydroidengattung Eudendrium