I have been witnessing this Caspian pollution time by time from my childhood. From 2016 while walking on Caspian side in the early morning a silent voice of the sea asked me to show its pollution. We usually prefer not to see unpleasant things and the economy of my country is based on oil, that's why there was no earthly reason to just complain about it. From that time I was looking for an aesthetic way to draw attention to this problem. This is how i guess fishes see oil spots on Caspian sea from bottom.