What are the effects of the dead zone?
The overgrowth of algae consumes oxygen and blocks sunlight from underwater plants. When the algae eventually dies, the oxygen in the water is consumed. The lack of oxygen makes it impossible for aquatic life to survive.
What is the main cause of the dead zone in the Gulf of Mexico?
Human activities in urban and agricultural areas throughout the Mississippi River watershed primarily cause the annual “dead zone.” Excess nutrients flow into the Gulf of Mexico and stimulate an overgrowth of algae, which die and decompose. The algae deplete oxygen as they sink to the bottom.
What is the Gulf of Mexico dead zone and when does it happen?
Every summer, a low-oxygen area, often referred to as a Dead Zone, develops off of the Texas-Louisiana shelf when nutrient-laden fresh water from the Mississippi and Atchafalaya Rivers flows into the Gulf of Mexico.
What is the dead zone in Gulf of Mexico?
The hypoxic zone in the northern Gulf of Mexico is an area along the Louisiana-Texas coast, where water near the bottom of the Gulf contains less than two parts per million of dissolved oxygen, causing a condition referred to as hypoxia. Each summer, the size of the hypoxic zone is measured.
What human activities are affected by dead zones?
These activities include agriculture, waste deposition, wastewater treatment and pollution from factories. Causes of dead zones (slides 7 and 8) 1. Dead zones are one result of eutrophication, an ecological imbalance that occurs because of excess nutrients like nitrogen and phosphorus.
When does a dead zone form in the Gulf of Mexico?
A dead zone forms seasonally in the northern Gulf of Mexico when subsurface waters become depleted in dissolved oxygen and cannot support most life (fig. 1). The zone forms west of the Mississippi Delta over the continental shelf off Louisiana and sometimes extends off Texas.
Where is the hypoxic zone in the Gulf of Mexico?
Measuring the Hypoxic Zone. The hypoxic zone in the northern Gulf of Mexico is an area along the Louisiana-Texas coast, where water near the bottom of the Gulf contains less than two parts per million of dissolved oxygen, causing a condition referred to as hypoxia. Each summer, the size of the hypoxic zone is measured.
What happens to fish in the Dead Zone?
When the water reaches this hypoxic state, fish and shrimp leave the area and anything that can’t escape like crabs, worms, and clams die. If the amount of pollution entering the Gulf isn’t reduced, the dead zone will continue to wreak havoc on the ecosystem and threaten some of the most productive fisheries in the world.
How are dead zones and harmful algal blooms related?
The Effects: Dead Zones and Harmful Algal Blooms. Excess nitrogen and phosphorus cause an overgrowth of algae in a short period of time, also called algae blooms. The overgrowth of algae consumes oxygen and blocks sunlight from underwater plants. When the algae eventually dies, the oxygen in the water is consumed.