Synaptic Snaps, Crackles & Pops

Gulf of Mexico Dead Zone [Journalistic Intentions, Rd 8]

Who doesn't enjoy shrimp cocktail (assuming you occasionally frequent places that offer such fine fare)? I, for one, certainly enjoy a heaping helping of chilled shrimp, along with the tangy cocktail sauce that normally accompanies it. Perhaps you've wondered why the price of this tasty appetizer seems to fluctuate more than the meal to follow. There are various reasons, but a big one is the Gulf of Mexico Dead Zone, a region of bottom water off the Texas-Louisiana coast in the northern Gulf that's at its worst during the summer months.

Fresh water pours into the Gulf, mainly via the Mississippi and Atchafalaya Rivers, bringing excessive nutrient pollution from a drainage basin that touches 32 U.S. states. Since the summer is a quieter period, storm-wise, the warm surface waters containing plenty of oxygen don't get as much opportunity to mix with the cooler waters in the deeper parts of the Gulf. Dead plant material carried downstream makes its way toward the bottom of the Gulf and is consumed by bacteria (leaves gotta fall, bacteria gotta eat, right?). The problem is, bacteria's eating process includes the use of oxygen, thus creating this hypoxic

low-oxygen

zone. This area then grows and grows, forcing marine life that are strong enough to swim away to abandon the area, and killing those too weak or unable to swim to escape; shrimp fall into the latter category. Fewer large shrimp are harvested, so the cost of that cocktail goes up.

Remedies being explored include more efficient use of fertilizers upstream and river diversions to restore coastal wetlands. This last strategy will help filter out the excessive nutrients, as well as helping the wetlands to flourish. If these projects work as intended, we can be reasonably assured of less expensive shrimp and Louisiana can keep that brown pelican on their license plates.