Turkey forms the southern border of this sea
But as it has 
moved to clamp down on its southern border, critics say it has... [DOC] [TLE] Tigris-Euphrates river system | river system, Asia | Britannica.com [PAR] Jan 20, 2016 ... At Al-Qurnah the rivers join to form the Shatt al-Arab in the southeastern corner of 
Iraq, which empties into the sea