(CNN) -- Some have called it the Garden of Eden. At one time, the lush marshes of southern Iraq nourished a thriving array of wildlife and half a million people known as the Marsh Arabs.

Today, the region is not the "Fertile Crescent" it once was.

Twelve years ago, Iraqi dictator Saddam Hussein ordered the destruction of the marshes in retaliation for an uprising against his regime.

Satellite images and U.N. reports indicate that by 2002 about 7 percent of the wetlands remained. Experts began to fear that they would be gone by 2008.

Today, researchers hope that what Saddam destroyed, science can help regenerate. They are seeking to reverse the damage from years of damming and draining of the marshes.

Sitting at the confluence of four rivers, the vast Mesopotamian wetlands were once considered among the world's most important habitats. Sheltering migrating birds and spawning grounds for fisheries, they spanned about 8,000 square miles.

"Sixty percent of the fish consumed in Iraq in 1990 was from the marshes," said Dr. Azzam Alwash, director of the Eden Again project, one of the groups charged with rebuilding the wetlands.

Today, the marshes, which are critical for fisheries, have decreased by nearly 50 percent in some areas, said Dr. Curtis Richardson, director of Duke University Wetland Center...