The Aral Sea was once the world’s fourth largest lake - a rich haven for fish, birds and other wildlife. It was also home to bustling fishing ports such as Aralsk, which was once at the heart of the fishing industry in Kazakhstan.

But starting in the 1960s, massive agricultural expansion in the Aral region saw much of the water from the two rivers that feed the lake diverted into thousands of canals, to irrigate crops.  This caused the Aral Sea to shrink by 70 per cent and split into two – known as the North Aral and the South Aral, and leaving ports like Aralsk high and dry, many miles from the sea. This must surely count as one of mankind's greatest environmental blunders.

But the North Aral is now being revived. The World Bank and the Kazakh government are spending millions of dollars to re-fill it and help revive its ecosystems. The first step is to make sure water from one of the region’s main rivers is more evenly split between agriculture and the sea.

Several hundred kilometres up stream from the North Aral, on the Syr Darya river is the Aitek Wier. The river used to be partly blocked here so that water could flow into irrigation canals. But the weir is more efficient than the previous dam and allows much more water to flow into the sea. When the river water reaches the sea, the 13-kilometre-long Kok-Aral dam allows it to collect and build up.

As a result, the surface of the North Aral is now 50 per cent larger than it was at its lowest point. The dam does, however, effectively cut off the water supply to the larger South Aral, which continues to shrink. But most people agree it is the lesser of two evils because without this dam neither North nor the South Aral could survive.

When the sea shrank it became very salty, causing all of the freshwater fish species to disappear. But the increase of freshwater means that the Aral’s ecology is making a comeback. Many of the fish species are now returning from the rivers where they took refuge. But they still need a helping hand.

In the village of Tastak a fishery is breeding five types of fish, including native carp and sturgeon, for re-introduction into the lake. The fish hatchery also boosts fish numbers by giving the breeding fish a hormone to stimulate egg production. As a result one fish can produce around 250,000 larvae, and this summer the fishery hopes to release four million juveniles into the North Aral.

The return of the fish has also meant the return of the fishermen. Since 2007 the annual catch in the North Aral has doubled.

But there are still problems here - fishing restrictions are often flouted and the earthrise team found later that even the fishermen who took part in the filming were using cheap, non-regulation nets.

Serik Duisenbayev, from Aral Tenizi, a fishermen’s NGO, says that the lesson from the near-destruction of the Aral is that we must "…keep the balance between nature and humans beings. I think not only people of Aralsk and Kazakhstan. I think it should be a good lesson for the whole world now".

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Source: Al Jazeera