The rich habitats of the Gulf of Mexico help make it one of the most ecologically and economically productive bodies of water in the world. Its environments range from sandy, ever shifting barrier islands to muddy, tide-washed marshes, from frigid dark zones miles deep to immense islands of floating seaweed. The Gulf, though, faces serious problems today, including oil spills, overfishing, extensive wetlands loss, and a huge oxygen-starved "dead zone" at the mouth of the Mississippi River. For ages 9 and up. WARNING: CHOKING HAZARD - Small Parts. Not for children under 3yrs.