56: Ocean Dead Zones

Human behavior on land has no more dramatic example of the catastrophic results in the ocean than the dead zone—large coastal areas so polluted by runoff and starved of oxygen that they cannot support marine life. There are more than 400 such hypoxic zones on the planet (a number that’s doubled since 1960.) Other coastal dead zones are located in the Gulf of Mexico (at the mouth of the Mississippi River,) the Kattegat Sea in Norway, the Pacific Northwest, and the Chesapeake Bay.