UN Secretary General Ban Ki-moon took a helicopter tour over the Aral Sea on Sunday, seeing first hand the environmental devastation the receding waters have left behind.

Ban, on a visit to Uzbekistan during a tour of Central Asia, circled over the sea and landed in the former coastal fishing town of Muynak, which is living evidence of the manmade tragedy.

The United Nations chief said the disappearance of the sea was one of the world's worst environmental disasters and called on Central Asian leaders to do more to address the problem.

The Aral Sea, which straddles the border between Kazakhstan in the north and Uzbekistan in the south, was once the fourth largest inland body of water in the world, and until the 1980s, Muynak was a busy fishing port.

Now, however, the nearest water is about 100 kilometers (60 miles) away, and the boats that were the town's economic lifeblood lie abandoned on the dry seabed.

The lake began to shrink in the 1960s, when the Soviet Union embarked on a vast irrigation project, diverting water from the Syr Darya and Amu Darya rivers that fed the Aral Sea to cotton production in the Central Asian deserts.

Since then, the water level has dropped by 18 meters. As the volume of water in the sea has decreased, its salinity has increased, killing off marine life.

During the 1990s, the dry seabed became a salt desert covering thousands of square kilometers, drastically changing the local climate and wreaking further ecological damage.

While efforts by Kazakhstan to restore the North Aral Sea have met with some success, the larger southern section could disappear by the end of the decade.

Ban arrived in Uzbekistan after visits to Turkmenistan and Kyrgyzstan. He will hold talks with President Islam Karimov and move on to Tajikistan before wrapping up his tour in Kazakhstan.

TASHKENT, April 4 (RIA Novosti)