Blooming of Danube 10 images Created 24 Aug 2013
The increase of the water quality helped the mayfly species to return to river Danube. Possibly their genetic material returned from the river Raba. Unlike the more commonly known longtailed mayfly species that swarms on river Tisza these insect swarm during the night and artificial light sources impose great danger to them as lights of a nearby bridge and cars crossing it attract the insects in large numbers thus many of them die before perpetuation.