It sounds futuristic, but “Dead Zones” exist in our water environments and are rapidly increasing in size and number. Why? A Dead Zone is a body of water with greatly reduced oxygen, often causing marine life to die. Habitats that were once teeming with life are reduced to biological deserts. Run-off of nutrients from farming is a major culprit. The Brothers travel to the Gulf of Mexico and Lake Erie to examine two of the world’s largest and most notorious Dead Zones.