The Death of the Aral Sea

The Aral Sea region has been officially declared a disaster area.  Thirty years of growing water-intensive crops in the desert has led to the present crisis.  Water from the Syr Darya and Amu Darya rivers that is needed to replenish the Aral Sea has been diverted to irrigate cotton and rice crops.  The sea has lost 60 percent of its volume, increasing the salt content to four times its natural level.  The shoreline has retreated to 40 miles from where it once was.  Saving the sea would require an immediate halt to all irrigation upstream, which would end cotton production.

The cross-curriculum experient in Geography and Biology undertaken by the 7EU2 shows how changes in the concentration of salt can affect plant cells.

Here is what we did!

We put three pieces of onion in three different glasses labeled „no salt“, „low salt“ and „high salt.“  We then compared the flexibility of the onions after 30 minutes, one hour and overnight. 

Here is what we found out!

The flexibility of the onions after 30 minutes was similar, but after just one hour, the flexibility of the onions in the salty water increased already.  The next morning it was clear to see that the „high salt“ onion was very squishy, the „low salt“ onion was also very flexible, but the „no salt“ onion stayed crispy.  Living cells can respond to their surroundings by either releasing or absorbing water.  In this case the onion cells released all their water due to the salt.  The Aral Sea is in desperate need of help.  But what can Kazachstan and Uzbekistan do to decrease the salt content of the Aral Sea?  Can Europe help?  There are definitely no easy answers.