An investigation carried out after a signal was received about an unnatural dark brown colour of the water near the beach in the Varna district of Asparuhovo, as well as in the entire area of the port of Varna on the Black Sea coast, has revealed that the cause is not pollution, but a natural phenomenon. 

This was stated by Veneta Slavova - inspector of the State Environmental Control of Shipping at the Executive Agency "Maritime Administration" in Varna. She pointed out that it was a rapid bloom of plankton due to the quick warming in recent days and recalled that there was a similar situation a few years ago when the sea water turned bright red. The information was provided by BNR correspondent in Varna Daniela Stoynova.