The cause of the red waters behind Pub 1837 in Nootdorp is almost certainly a natural bacteria or algae, says spokeswoman Inka Vogelaar of the Delfland Water Board. Although authorities say there has been no ill effects on fish, people in the area have been advised to avoid the water.
Bodies of water turning red is not a new phenomena and has been reported in other areas around the world recently. Researchers believe the red waters are linked to a rise in bacteria and rare algae blooms, another symptom of our changing and warming climate.