Large Gulf of Mexico “Dead Zone” Validates Forecast Model Based on Nitrate Loading
A NCCOS-sponsored survey cruise conducted on the R/V PELICAN July 21-29, 2007 found that this year’s Gulf of Mexico “dead zone” was the third largest on record since annual measurements began in 1985. The observed area, 7,900 square miles, was 7% lower than the 8,500 square miles predicted by a NCCOS-funded forecast model. The model is based on nitrate loads from the Mississippi and Atchafalaya rivers in May and incorporates the previous year’s load.
The closeness of the model predictions in this and previous years indicates an association between springtime nitrate loading and hypoxic zone area. NCCOS is a key player in an ongoing scientific reassessment and revision of the Hypoxia Task Force’s Action Plan for Reducing, Mitigating, and Controlling Hypoxia in the Northern Gulf of Mexico that will articulate a management strategy to reduce the size of the dead zone in the northern Gulf of Mexico.