Accumulation of polychlorinated biphenyls [PCBs] in navigation channels, harbors and industrial areas of the Bahia Blanca estuary, Argentina

The usage and production of polychlorinated biphenyls [PCBs] was banned in Argentina in 2002, approximately twenty to thirty years later than in other countries. A total of 29 sediment samples [up to 14 m deep] were analyzed for a mix of seven individual PCBs in a time series for over more than one year in twelve selected locations, including harbors, recreational docks and several industrialized coastal locations in Bahia Blanca Estuary, Argentina, South America. The GC/ECD results showed the dominance of three chlorinated compounds: CB180, CB52 and CB101, which showed a strong reduction with distance from the urban area. The principal components analysis differentiates light and heavy congeners variation, settling several hypotheses and the classification of sampling sites to determine the PCB burden. Considering literature reports, the present results were evaluated in the international PCB context, diminishing the scarcity of PCB data from the Southern Hemisphere and prompting the need of future monitoring approaches

Lessons from multi-decadal oceanographic monitoring at an estuarine ecosystem in Argentina

Both climate change and anthropogenic impact are creating a dynamic of continuous changes in ecosystems. While the expected consequences of these changes are global, the occurrence of extreme events and specific environmental problems are usually local or regional phenomenon. In particular, the coastal ecosystems are among the first vulnerable areas to show those changes; in spite of this, are the least studied. The Bahia Blanca estuary, Argentina, is located at 38° 40' S and 62° 09' W with an area of 2300 km[2]. Along the northern shore of the estuary it is found the most important deepwater harbor of the country, where most of the agricultural and industrial products are exported. For the first time, based on multi decadal oceanographic monitoring and meteorological data of this ecosystem, a co-relational analysis approach was outlined considering several documented changes at various trophic levels; namely, phytoplankton and zooplankton assemblages, commercial crustaceans and fisheries. As results, several novel emerging hypotheses regarding cause-and-effect relationships were formulated. These unprecedented findings represent substantial information for the focus of the future ecosystem management and research, revealing gaps in the present knowledge of the coastal ecosystem which can be extrapolated to other worldwide coastal systems