Investigations into the cause of a number of dead fish found recently in the Guadiana river are ongoing, but environmental authorities have confirmed the water is not a public health hazard.
Analysis conducted by the Portuguese Environmental Agency (APA) shows that there have been no changes in the quality of the water which still possesses high levels of oxygen.
It is suspected that the dead or dying fish were dumped illegally in the river by fishermen due to their low commercial value.
Another possible explanation is the sudden rise in water temperature caused by the south-eastern currents. However, since the dead fish are all of the same species – mullet – the most logical option is illegal dumping.
Three quarters of the fish have been recovered by the respective authorities and are currently being analysed.
