title: Cesium-137 concentrations in marine macroalgae from different biotopes in the Aegean Sea (Greece).
abstract: The commonest species of red, brown, and green macroalgae were sampled from a range of biotopes in the Aegean Sea during 1998 for their 137Cs content. Significant differences in 137Cs concentrations were found among different species growing under similar environmental conditions, suggesting that uptake does not follow physical levels but is influenced by allometric parameters and physiological mechanisms. 137Cs content in collected seaweeds were in the descending order: Ulva lactuca>Enteromorpha linza>Gracilaria verrucosa>Ceramium rubrum>Cystoseira barbata. A comparison of the stations studied indicated that the degree of accumulation is also dependent on the geomorphology of the specific area. The west side of Thermaikos Gulf, where the rivers Axios, Aliakmon, and Pinios flow, was highly contaminated as was the Strymonicos Gulf where the river Strymon flows. High cesium concentrations were also observed in algae from Lemnos Island near the mouth of the Dardanelles Channel, most likely due to the horizontal circulation of water masses from the Marmaras Sea to the Aegean Sea resulting in the discharge of 137Cs during the purification process in the Black Sea through the Dardanelles Straits. It is concluded that the general dispersion of 137Cs results from the water circulation regime within the Aegean Sea. Higher levels are present in the northern part of the basin due to current circulation originating from the Black Sea and from outflow of rivers. Levels decrease to the south and east, but increase again to the west of Crete where the Black Sea water mass can be periodically traced.
authors.affiliation: Department of Botany, Faculty of Biology, Aristotle University of Thessaloniki, P.O. Box 109, GR-54006 Thessaloniki, Greece.
authors.forename: Thomas
authors.initials: T
authors.lastname: Sawidis
authors.forename: Gerorg
authors.initials: G
authors.lastname: Heinrich
authors.forename: Murray-T
authors.initials: MT
authors.lastname: Brown
mesh_terms: D002588:Cesium Radioisotopes / Q000032:analysis* / Q000493:pharmacokinetics; D004784:Environmental Monitoring; D056890:Eukaryota / Q000737:chemistry*; D055593:Geological Phenomena; D005844:Geology; D006115:Greece; D011210:Power Plants; D011847:Radioactive Fallout / Q000032:analysis*; D018788:Radioactive Hazard Release; D014455:Ukraine; D014875:Water Pollutants, Radioactive / Q000032:analysis* / Q000493:pharmacokinetics
chemical_list: D002588:Cesium Radioisotopes; D011847:Radioactive Fallout; D014875:Water Pollutants, Radioactive