(Image: KARI/ESA)

YOU’RE looking at a gigantic algal bloom – seen from space. This is the Caspian Sea, located between Europe and Asia, bordered by Russia, Azerbaijan, Iran, Turkmenistan and, seen in the lower portion of the photograph, Kazakhstan.

The sea – or lake, if you prefer, as it is landlocked – is enormous, with a surface area of 371,000 square kilometres. It’s larger than Germany. But the section seen here is shallow, only around 5 metres deep. It is also polluted by phosphorus from fertiliser, raw sewage and detergents, and the super-enriched water triggers massive growth of algae just as …