Journey with Nature  Gulf Hypoxia  The "dead zone" off the coast
of Louisiana and Texas in the Gulf of Mexico is thought to be at
its largest size on record. But what is this dead zone, and what
does it have to do with Indiana?  Gulf Hypoxia: What is It and
How are We to Blame?  The scientific word for the commonly named
"dead zone" is hypoxia, or low oxygen. The lack of oxygen in
these waters creates an area where marine life must struggle to
survive if they survive at all. Out of all the coastal waters
exhibiting hypoxia, the Gulf of Mexico is the second largest in
the world. Several factors cause this phenomenon, but the water
drained from the Mississippi River into the Gulf is primarily to
blame.  A combination of physical, chemical and biological
factors creates the conditions that result in hypoxia. During
most of the year, oxygen-rich water reaches the bottom. However,
in late spring and summer, the surface and bottom waters of the
Gulf stratify into two layers. Warm, less dense freshwater from
the Mis