The Gulf of Mexico's "dead zone," an area affected by low oxygen levels, could expand to a record 22,000 sq. kilometers (8,494 sq. miles) this year, well above the average, the National Oceanic and Atmospheric Administration, or NOAA, said.

Researchers at the University of Michigan, Louisiana State University and the Louisiana Universities Marine Consortium are forecasting that this year's dead zone could be "among the ten largest recorded," NOAA said in a statement.

The dead zone is created when the waters of the Mississippi River flow into the Gulf of Mexico, introducing fertilizers and animal waste from farms into the body of water.

"Hypoxic (very low oxygen) and anoxic (no oxygen) zones are caused by excessive nutrient pollution, often from human activities such as agriculture, which results in insufficient oxygen to support most marine life in near-bottom waters," the federal agency said in a statement.

Algae blooms in high-nutrient areas in the Gulf. When the algae dies, bottom-dwelling bacteria consume the decomposing matter, using up oxygen.

Fish and mollusks leave low-oxygen areas or die, resulting in a loss to commercial and sports fisheries.

"Aspects of weather, including wind speed, wind direction, precipitation and temperature, also impact the size of dead zones," NOAA said. EFE