Ökologische Kriterien der Technik- und Stoffbewertung: Integration des Vorsorgeprinzips

The development of criteria for the comparative assessment of technologies and substances beyond the toxicological approach and the development of an integrated pattern of criteria is still at the beginning. The criteria presented here for integrating the precautionary principle into the substance and technology assessment have to be further operationlised and completed, in the same way as the criteria which have been discussed and developed within the framework of

- the poisoning and pollutant paradigm

- the equilibrium paradigm

- the sustainability and “Mitwelt” paradigm

- the energy and the general technology assessment debate.

The resolution of the criteria has to be improved and their range (which is certainly limited) has to be explored more precisely. The application of the criteria should never occur mechanically. Technology assessment and substance assessment are not only scientific, but essentially social and, hence, discursive processes. It is not so much the assessment of individual substances which should be in the center of the debate, but rather the comparative assessment of competing techniques, substances and substancerelated development pathways (see vonGleich andRubik, 1966 as a first approach to assess the environmental effects of old and new materials). According to the example of the energy strategies, only the development of competing strategies in the substance field could create the necessary prerequisites for a broad public discourse and thus for a democratisation of the basic substancerelated policy decisions. This discourse is a duty which science and economy have toward society.     

Geographical patterns in reproductive biology of the Pan-American sandy beach isopod<Emphasis Type="Italic"> Excirolana braziliensis</Emphasis>

Eleven populations of the Pan-American sandy beach isopod Excirolana braziliensis, distributed from tropical (9°N) to temperate (39°S) sandy beaches in Atlantic and Pacific Oceans, were analyzed to determine latitudinal variations in: breeding and recruitment patterns, sex ratios, size of ovigerous females and of juveniles and length–fecundity relationships. E. braziliensis exhibited strong latitudinal patterns in all reproductive traits throughout its distribution range. Breeding and recruitment shifted from continuous to seasonal from tropical to temperate beaches, having a predominance of females at higher latitudes. In agreement with the latitudinal gradient hypothesis, ovigerous females inhabiting tropical sandy beaches (low latitudes) were smaller, became sexually mature at smaller sizes and had lower individual fecundity than on temperate beaches. Juveniles were also smallest at low latitudes. Between-ocean comparisons showed very similar reproductive characteristics for roughly the same latitude. These linked reproductive parameters suggest that the intensity of breeding effort is associated with the duration of the breeding season and geographically size-related characteristics of the species. Geographic variations in the breeding and recruitment seasons, as well as in individual fecundity, size structure of mature females and sex ratios, are proposed to have major consequences in explaining local variations in population demography. Our paper also reinforces the notion that sandy beach animals are highly plastic.Communicated by O. Kinne, Oldendorf/Luhe     

Photoacoustic determination of the thermal properties of bivalve mollusk shells

We used the photoacoustic technique for characterization of the thermal properties of adult shells of American oyster Crassostrea virginica (Gmelin, 1791) and the mussel Ischadium recurvum (Rafinesque, 1820). Heat transport is more efficient in C. virginica than in I. recurvum shells, reflecting the different architecture, microstructure, and composition of the two kinds of shells. Published online: 4 July 2002     

Lead monitoring in air,soil and foliar deposits at Indore city with special reference to automobile pollution

Ambient lead levels in air, soil and dust deposits on selected plant species at ten distinctly located sampling stations of Indore city are presented. The maximum lead level in air was recorded at Palasia, where the traffic density was found to be the highest. Out of the plant species studied, the maximum lead was recorded on Dalbergia sissoo leaves. A possible relationship between leaf morphology and dust accumulation tendency is also discussed.     

Changes in the feeding behavior of the deposit-feeding polychaete<Emphasis Type="Italic"> Laeonereis acuta</Emphasis> on soft sediments inhabited by burrowing crabs

In this paper, we evaluate the influence of the burrowing crab Chasmagnathus granulatus on the feeding behavior, body condition, burrowing activity, and fecal production of the deposit-feeding polychaete Laeonereis acuta. Previous results and ours show that, due to crab activity, sediment organic matter decreases with depth outside a crab bed, but there were no differences inside. Also, particle sizes were smaller inside the crab bed. Polychaetes showed better body condition inside the crab bed, suggesting higher energy gain. They fed on the surface more frequently outside the crab bed than inside. However, feeding rate was higher inside the crab bed, which is consistent with the larger weight and volume of fecal pellets found inside crab bed. In both areas, the bedload sediment transport was not similar to the sediment ingested by this polychaete. A 1-month exclusion/inclusion experiment performed outside and inside the crab bed showed that the body condition of polychaetes changed between areas but that this was not directly due to crab manipulation. Thus, our results suggest that the higher sediment quality inside a crab bed can positively affect the feeding behavior of the deposit-feeding polychaete L. acuta, increasing its feeding rate and consequently enhancing its body condition.Communicated by P.W. Sammarco, Chauvin     

Application of ‘Landsat’ data to resource management

Over the past few years, a great deal of interest has been focused on the use of remote sensing for resource management. This paper examines one of the most useful systems — Landsat. Included in this paper is a discussion of this remote-sensing technology, its application and its future as a tool for resources planning and management.     

A ciliate red tide at Barrow,Alaska

In September 1968 the first occurrence of extensive red water in the Arctic Ocean in the vicinity of Point Barrow, Alaska, was recorded. The organism causing this water discoloration was a fairly large (100 to 150 ) ciliated protozoan, with chlorophyll-containing endosymbionts. This ciliate, which is not identical to the commonly reported Mesodinium or Cyclotrichium species, is described in this paper, but cannot be identified with any organism described in the literature. Concentrations of dissolved inorganic nutrients and trace metals were determined on water samples obtained from the red water and also in the clear water adjacent to it. These data are discussed relative to the hydrographic conditions in the Chuckchi Sea around Point Barrow. A direct species' analysis by microscopic methods indicated that the plankton were quite similar in all the water samples except for the aforementioned red ciliate, which accounted for over 90% of the total cellular organic carbon in the samples from the red water. Chemical analyses indicated that the red tide ciliate contained approximately 51% protein, 33% lipid, 8% carbohydrate, 0.2% chlorophyll a, and 1.2% DNA.