KAZAKHSTAN. Bogen. 2009. The North Aral Sea viewed from a fishing boat near Bogen village. The sea used to sustain more than 30 species of fish, but the number was drastically reduced after intensive irrigation shrunk the sea by almost 75 percent. Now, thanks to the construction of the Kokaral dam in 2005, which reduced salt levels and caused the water level to rise, a few species have returned to the sea.