These images show how the waters of Spain’s longest river have turned green around the ‘Spanish Stonehenge’ because of algae which are “threatening the ecosystem”.
The unexpected phenomenon happened in the waters of the Valdecanas Reservoir which is on the Tagus river in the province of Caceres in the autonomous community of Extremadura in south-western Spain.
The images were taken by the photographer Alberto Rubio from the municipality of Berrocalejo in the Dolmen of Guadalperal, dubbed in local media as the ‘Spanish Stonehenge’, a megalithic monument – dating back to from between 2000 and 3000 BC – which became visible a couple of months ago due to droughts in the Valdecanas Reservoir.
According to Spanish ecologist confederation Ecologists in Action the waters have been invaded by algae which have spread in the waters of the river due to the droughts in this region of Spain and the high temperatures in the summer.
The algae reportedly consume high levels of oxygen and threaten life in the river, killing fish.
The green waters have also affected the river waters in the national park of Monfrague where some locals have said it looks “radioactive green”.
Photographer Alberto Rubio said that the water supply in the municipality of Berrocalejo has been cut due to the algae invasion.
Rubio told Central European News (CEN): “The green in the water is threatening the ecosystem in the reservoir and causing the death of fish. Moreover, it is causing an increase in the arsenic levels in the water and the municipality of Berrocalejo water supply has been cut.”
According to local media, the past water year, which started on the 1st of October 2018 and ended on the 30th of September 2019, was the fourth driest year of the century in Spain.