Have you heard of Bosphorus Strait?
This strait connects continents of Asia and Europe in Istanbul, capital of Turkey.
People noticed this change as the colour of strait was bluish earlier and changed to milky turquoise this week.
This sudden change has been attributed by scientists to increasing level of pollution in the sea and surge in a species of plankton across the Black Sea.
Other reasons cited are earthquake in the region on 12th Jun 2017 afternoon and surge in micro organism Emiliania huxleyi popularly known as Ehux.
If this continues, it may endanger species of fish and other animals living in the sea in this area and may result in decline in tourism and protests by environmentalists.