The ELOISE projects evaluating specifically riverine contaminant supplies are BIOGEST (estuarine biogas, northern Europe – commented in section 5. Atmospheric pathways: from sea to land), EROS-21 (Black Sea), EUROCAT (various), and TOROS (metal contamination, S.Spain). In addition, of partial relevance are the fluvial projects dealing with nutrients DANUBS (Black Sea), INCA (various), MANTRA-EAST (north-east) and STREAMES ( Mediterranean).

Metal mining at present and as a legacy has provided one theme of research into riverine transport of metal contaminants to the coast. The TOROS project focuses on fluvial transport from the long term mining regions around Rio Tinto and Rio Odiel to the coast of southern Spain. Chronic release (2500 years), mine drainage, phosphogypsum waste runoff and acute discharge (collapse of Los Frailes tailings dam, Aznalcollar) are features of this case study. Comparison of the total transport of some metals drawn with other European river systems is a measure of the severe situation. Contaminant flows to Western Mediterranean were also investigated by TOROS (Table 2). For example, mercury concentrations flowing into the Bay of Cadiz are put at ten times greater than those transported by the Seine to the Normandy coast, generally held to be a relatively contaminated river. Comparisons with mine impacted rivers in the UK also shows the Rio Tinto to be a much more heavily metal laden river (Braungardt et al., 2003). Acidic and metal rich waters exist down as far as salinities of 30 o/ oo in the estuary.

Physical characteristics of transport are explored to examine the sink mechanisms operating. Removal of mercury (Hg), aresenic (As), and uranium (U) by sediment and also seasonally by algae fixation (Elbaz-Poulichetet al., 2000) during transport to the coast is contrasted with limited removal of other metals in the coarse of downstream transport. Precipitation of dissolved components and co-precipitation with iron is also observed, and the factors dictating suspended particulate-dissolved metal relationships explored (Achterberg et al., 2003).

The project also attempts to budget the estimates of metal inputs into the western Mediterranean Sea, by rivers, modelling dispersion along the coast, and through the Straits of Gibraltar (Elbaz-Poulichetet al., 2001a & Elbaz-Poulichetet al., 2001b). These figures indicate that for components other than arsenic the Rio Tinto is far from an inconsiderable source of total inputs. That this Mediterranean river system is so much more heavily metal laden than other local rivers, indicates the long term legacy which can result from mining in Europe. Simultaneoulsy, evaluation of the effects of acute release with the Los Frailes tailings dam collapse indicated no impact on coastal chemistry after six months (Elbaz-Poulichet et al., 1961-1973). Of course, the high existing baseline should be recognised when interpreting such an assessment.

Another case with restricted long term consequences of elevated contaminant discharge is the Danube . The EROS-21 project demonstrated that despite high discharges in the past before recent economic changes, at present the fluvial flows of contaminants into the Black Sea from the Danube are not generally high (Guieu & Martin, 2002). Only copper and lead show elevated inputs of metals in particulate form, with copper alone being elevated in dissolved form. The source of this is believed to be upstream mining. Release from surface runoff or contaminated sediments does not seem to be a particular issue. The Danube system, notable as a transnational river open to variable control strategies, does not appear to act as a conduit for elevated metal input to the Black Sea. Indeed, it appears able to ameliorate both any release of metals to the river system further upstream, and release from sediment. Amongst organic contaminants, organochlorine levels were found to be ‘average’ for European rivers. HCH registers higher, this being evidence of continued lindane use within the catchment (Maldonado & Bayona, 2002).

A further evaluation undertaken within the EROS-21 project was to review the rate of transmission of radioactive material along the river courses (Gulin et al., 2002), as a result of radioactivity arising from the Chernobyl accident. A five-ten year delay was observed before the peak inflow of radioactivity occurred in the Danube and Dnieper.