The 2019 forecast is based on U.S. Geological Survey river flow and nutrient data. The dead zone is an annual occurrence that starts far from the ocean, all the way up in the Mississippi River Watershed.
Because of fertilizer use, agricultural lands contain high amounts of nitrogen and phosphorus, two of the main ingredients in fertilizers. Spring rains and heavy rains any time during the year creates run-off and all this ends up flowing into tributaries and eventually the Mississippi River.
When those nutrients reach the mouth of the river and flow into the warm waters of the Gulf, they prompt an overgrowth of algae. But once the algae blooms die, they sink to the bottom of the Gulf, creating a “dead zone” or area of hypoxic waters and depriving fish and other marine life of the oxygen they need to survive, according to CTV News Canada.
This low oxygen or “dead zone” will likely cover an area of about 7,800 square miles (20,200 square kilometers), close to the record size of 8,776 square miles set in 2017 and larger than the 5-year average measured size of 5,770 square miles.
This year’s dead zone will be much bigger than usual due to the high rates of rainfall which we had this winter creating more run-off. According to the US Geological Survey. It is estimated that the amounts of nitrogen and phosphorus entering the Gulf of Mexico this year will be 18 to 49 percent above average\, according to Business Insider.
Impacts on the seafood industry
The biggest threat from a large and extended dead zone will be to the U.S. seafood industry. The Gulf supplies 72 percent of U.S. harvested shrimp, 66 percent of harvested oysters, and 16 percent of commercial fish. This means fishermen and coastal economies could suffer.
The Gulf Dead Zone may also slow shrimp growth, leading to fewer large shrimp,” the USGS said in a statement. This could mean higher costs of large shrimp at the marketplace and an economic ripple effect on the Gulf shrimp fisheries.
