Abfallwirtschaft: Neue Sichtweisen und Techniken

In den letzten Jahren werden in vielen Ländern eher die Abfallkomponenten als vielmehr die Stoffmischungen betrachtet. Das gesetzliche Rahmenwerk des Stoffstrommanagement kann dazu beitragen, die Probleme auf wissenschaftlicher Grundlage zu lösen. Der Einfluss der neuen Gesetzgebung in Deutschland und Europa auf das Stoffstrommanagement sowie auf die Entwicklung neuer Techniken bei Abfallentsorgung und-recycling wird in diesem Beitrag untersucht. Neue Prinzipien für das Abfallmanagement werden vom Management der Stoffströme abgeleitet.     

Pflanzenschutz: Neue Gesetze und ihr Nutzen

The debate about the revision of the EU directive 91/414 has often been characterized by unobjective criticism of the existing regulations and of the authorities involved in the regulatory procedure. This made many consumers feel uncertain and left the public with the impression that the current regulatory system for plant protection products in Europe was not safe for consumers and the environment. However, a detailed evaluation of these statements has clearly demonstrated that the current regulatory procedure is safe and recent scientific knowledge is taken into account. The risk potential calculated for aquatic and terrestrial organisms in Germany has continuously decreased since 1987. The effects and the benefits of the new regulations, which have reached a level of complexity as never before, are discussed in this context. From an industry perspective, clear legal regulations and practical implementations are essential to guarantee the transparence of the regulatory process and predictability of the outcome.     

Neue kriechede ctenophoren der gattung Coeloplana aus Madagaskar

Three new species of creeping ctenophores of the genus Coeloplana were found as ectocommensals on the octocoral Sarcophyton spec. in the Indian Ocean, near Madagascar, at water depths down to 45 m. The species are described as Coeloplana wuennenbergi, Coeloplana lineolata and Coeloplana punctata. Some observations on the biology and behaviour of these species were made in the field and under laboratory conditions. The new Coeloplaae differ from other Coeloplanae in colouration, colourmarks, position, and number of the aboral papillae, and in specific host-preference. The systematic significance of most characteristics, thus far described of Coeloplanae, are discussed and summarized in Table 1.     

Die Bedeckungsreaktion von Seeigeln. Neue Versuche und Deutungen

The conditions under which covering (“decorating”, “masking”) takes place have been studied in the sea urchins Paracentrotus lividus, Psammechinus miliaris and 2 other species. Covering occurs equally in darkness or light. It requires suitable objects and locomotion or searching activity of the tube feet. The covering reaction which may follow chemical, mechanical or optical stimuli may be purely the result of an increase in locomotory or general activity. Initial selection of different covering objects depends on the tube feet reflexes; size, form and weight of the object are important. Whether an object is accepted or not, depends on its surface and structure, the amount of water movement and the general activity level of the sea urchin. Transparency and colour of an object do not appear to be important. It is suggested that the covering process can be explained in terms of local tube feet and spine reflexes. The loading-up of objects may be understood as “relative walking”: the same reflexes which move the urchin on stable ground, draw loose particles towards the animal and then upwards.     

Neue ergebnisse über die aufzucht von Carcinus maenas im laboratorium

The shore crab Carcinus maenas was reared in the laboratory from egg deposition to sexual maturity. Special enclosures were developed for cultivation of the larvae. Food and temperature proved to be the most important exogenous factors for rearing success. Fresh Artemia salina nauplii were the only food suitable for all larval stages. The following rearing temperatures proved most successful during larval development: (1) embryonic development, 10°C; (2) zoea stages, 15°C; (3) megalopa stage, 17.5°C. The larvae hatch preferably in darkness when reared under short-day conditions.     

Neue EU-weite Höchstgehalte für Blei und Cadmium in Lebensmitteln

As of 5 April 2002, the maximum levels of the environmental contaminants, lead and cadmium, in different foodstuffs are now applicable for the first time throughout the entire EU. The toxicological assessment of lead and cadmium provides the basis for establishing maximum levels for these heavy metals in foods. The fixation of maximum levels results in obligatory regulations concerning the admissible burden of foods with these contaminants and, consequently, contributes to a health-related protection of the consumer. On 8 March 2001, the Commission issued a directive laying down the smapling methods and the methods of analysis for the official control of the levels of lead, cadmium and mercury in foodstuffs.