As a child, Iranian environmental journalist Maryam spent much of her time by the Caspian Sea. From her coastal home in the northern city of Rudsar, she witnessed how the water levels would fluctuate, so much so that in the 1990s, flooding along parts of Iran's northern shoreline left some of her relatives homeless. All that shape-shifting felt normal, yet on a recent trip back to the area after years away, the body of water was suddenly very unfamiliar.  "I kept walking further from the shore, but the water only reached my knees," said Maryam, whose real name DW has chosen not to reveal for security reasons. "For someone who grew up by this sea, it was frightening." What she experienced on that visit was not an anomaly. The Caspian Sea, the world's largest inland body of water, bordered by Iran , Russia, Azerbaijan, Turkmenistan and Kazakhstan is shrinking fast.…