A 25-year record of polycyclic aromatic hydrocarbons in soils amended with sewage sludges

We studied polycyclic aromatic hydrocarbons (PAHs) in crop soils amended with 1000 tonnes dry weight of sewage sludges per 10,000 m² from 1974 to 1992, then after sludges addition from 1993 to 1999. The absence of variations of total PAHs levels of control soils, averaging at 123 μg/Kg, shows the absence of horizontal contamination. During sludges addition, the total PAHs levels in amended soils increased from 232 to 402 μg/Kg. Seven years after sludges addition, it decreased to 275 μg/Kg, which is still more than twice –the levels of control soils. This finding shows that sludges PAHs are preserved in crop soils for long periods of time, on a human scale.     

Die vertikale verteilung und tägliche migration der hydromedusen (Hydrozoa: Coelenterata) in der Bucht von Eilat (Rotes Meer)

During the summer of 1970, plankton samples were made in the Bay of Eilat (Red Sea) to study the vertical distribution and diurnal migration of zooplankton. During this project, three programs of 24 h were carried out with a closing net. The hauls were taken every 2 h in different depths, together with measurements of temperature and salinity. The vertical distribution of hydromedusae, especially of Aglaura hemistoma, Péron and Lesueur, 1809 and Liriope tetraphylla (Chamisso and Eysenhardt, 1821), between the surface and 300 m is described. The diurnal migration for these two species was studied. Presumably temperature and salinity had no direct influence on vertical distribution and diurnal migration, as there was a homogeneous water body. The results are discussed.     

Zonation of the interstitial polychaeteStygocapitella subterranea (Stygocapitellidae) in European sandy beaches

The zonation ofStygocapitella subterranea Knoellner (Polychaeta, Stygocapitellidae) in sandy beaches is compared for several localities along the European coasts. In tidal beaches the species occupies a zone near average high tide level (AHTL), whereas in non-tidal beaches it is found at a fairly long distance from the water line. The regularities observed inS. subterranea indicate that the interstitial fauna may prove well suited for the establishment of a general scheme of zonation in sandy beaches analogous to that for rocky shores proposed byStephenson andStephenson (1949).