Recent aquatic ecosystem response to environmental events revealed from Pb-210 sediment profiles.

MULSOW, S.; PIOVANO, E.; DAMATTO, R.; CHAPRON, E.; CÓRDOBA, F.

Orlando, Florida.

Congreso; 2008 Ocean Sciences Meeting: ?From the Watershed to the Global Ocean?.; 2008

American Society of Limnology and Oceanography, American Geophysical Union, Oceanography Society, Estuarine Research Federation

The power of the sediment-water interface to record ecological events, anthropogenic impacts as well as catastrophic episodes is unquestionable. However, the reading of the record is based on proxies. Here we report anthropogenic, natural and catastrophic records on sediment cores collected in several depositional environments that may bring some light on the usefulness of Pb-210 as tracer rather than only a geochronological tool. In the mediterranean sediment cores (Morocco, Algeria), Pb-210 as well as its isotopic signature, clearly depict the origin of heavy metals contents. In another coastal aquatic system, 210Pb, is unable to represent sediment accretion and time, but rather a biogeochemical shift on the sediment water interface that took place few decades ago as a result of aquaculture (Southern Chile). In two different set of sediment cores, one from the Chilean Lake district, and the others from the Argentinean Pampa plains, depict similarly, on the 210Pb profile, sudden catastrophic natural events. We discuss the use of Pb-210 sediment profiles not only as a timing tool, but also as a tracer of environmental changes both natural and anthropogenic in aquatic ecosystems.