The temporal evolution of trace metal pollution on the Barcelona city continental shelf is linked to the evolution of the industrial activities and the urban development in the Besòs watershed, which includes a large part of the Barcelona metropolitan area. This pollution reached maximum levels during the eighties when the Besòs was probably the most polluted European river. However, at present, the trace metals content of the uppermost sediments accumulated during the last few decades shows a decline of up to one order of magnitude. Environmental regulations that are in place, including the operation since 1979 of wastewater treatment plants built in the Besòs River watershed, have drastically reduced the pollution levels in this highly populated and industrialized Mediterranean area, mainly during the 1990s. However, trace metal levels are still high. Water discharge during heavy rain events exceeds the treatment capacity of the existing facilities, leading to the maintenance of still significant levels of trace metals in sediments of the Barcelona city shelf. New strategies and approaches are needed

Peer Reviewed

2 pages