The Gulf of Mexico dead zone is an area of hypoxic waters at the mouth of the Mississippi River. Its area varies in size, but ca
n cover up to 6,000-7,000 square miles. The zone occurs between the inner and mid-continental shelf in the northern Gulf of Mexico, beginning at the Mississippi River delta and extending westward to the upper Texas coast. Thousands of farms are located along the Mississippi River and its tributaries and as water washes into the river after a heavy rain, it brings with it nutrients from fertilizers added to farmland. These materials flow downriver and eventually enter the Gulf of Mexico, where they create conditions for a dead zone: an area of low to no oxygen that results in the death of fish and other marine life. The Gulf of Mexico is a major source area for the seafood industry. The Gulf supplies 72% of U.S. harvested shrimp, 66% of harvested oysters, and 16% of commercial fish. Consequently, if the hypoxic zone continues or worsens, fishermen and coastal state economies will be greatly impacted. What can be done to minimize the Gulf dead zone? Choose ALL that could apply. A) Control of animal wastes so that they are not allowed to enter into waterways. B) Adjust the timing of fertilizer applications to limit runoff of excess nutrients from farmland. C) Monitor septic systems and sewage treatment facilities to reduce discharge of nutrients to surface water and groundwater. D) Restrict land use in the areas surrounding the Mississippi delta to exclude industrial sites. E) Counter the effects of fertilizers on algal growth in the Gulf with the use of chemical herbicides.
