Lead contamination in the roadside soils of Slovenia

The level of lead contamination along the roadway Ljubljana to Zagreb was established in 184 soil samples. The samples were taken from two depths (0–5cm and 15–20cm) and at different distances from the roadway. The influence of terrain morphology, prevailing winds, geological parent material and type of vegetation was estimated. Heavy traffic is confirmed as main source of lead contamination (average enrichment factor 17) in soils. The highest lead accumulation is localised in the top soil layer and within 10m from the roadside. Contamination with lead is more pronounced in soil samples from cuttings and slopes than in soils from plains and mounds. Soils derived from carbonate rocks contain higher lead concentration than those derived from other parent material.     

Direct and indirect trophic interactions of <Emphasis Type="Italic">Aurelia </Emphasis>sp. (Scyphozoa) in a stratified marine environment (Mljet Lakes,Adriatic Sea)

The pattern of diel vertical migration and the trophic interactions of moon jelly (Aurelia sp.) were investigated in the sea lakes of Mljet Island (Adriatic Sea) where this scyphomedusa is present throughout the year. Water column characteristics, plankton and in situ behaviour of Aurelia were followed over several 24-h cycles (6–8 times during each cycle) from the surface to the bottom (44 m). Aurelia exhibited a consistent pattern of diel vertical migration. Most of the time Aurelia were located at the bottom of the thermocline layer at temperatures lower than 19°C. Aurelia migrated towards the surface at dusk when the majority was found within the thermocline or just above it. During the night the medusae sank into the deepest layers below 25 m. The main medusa food items inferred from stomach contents were small adult copepods like Oithona nana and Paracalanus parvus and copepodites of small calanoids and cyclopids. In addition, in situ feeding experiments indicated high clearance rates for nauplii and naked ciliates and clear response of bacterial populations pointing to indirect cascade effects of Aurelia on microbial in addition to classical food web.     

Antigenic specificity of the sea urchin sperm surface

The antigenic composition of the sperm surface in Paracentrotus lividus Lam. and Sphaerechinus granularis Lam. was studied using the sperm agglutination test with homologous and heterologous antisera. The results indicated that sperm of both species have at least one antigenic determinant located on their surface and shared by both species. In addition, Paracentrotus sperm bear at least one species specific determinant on their surface. The existence of antigenic determinants common to gametes of both species was demonstrated.