The Gulf of Mexico's "dead zone" will not be resurrecting itself anytime soon, Canadian scientists say. The transport of large quantities of nitrogen from rivers and streams across the North American corn belt has been linked to the development of a large dead zone in the northern Gulf of Mexico, where massive algal blooms lead to oxygen depletion, making it difficult for marine life to survive.
According to an article in The NY Times, the "legacy sources" of nitrogen accumulated over the years due to farming, will likely keep contributing to the amount carried downriver, despite changes to farming and conservation practices. Researchers at the University of Waterloo believe achieving water quality goals for the Gulf of Mexico may take decades. “We are seeing long time lags between the adoption of conservation measures by farmers and any measurable improvements in water quality,” said Prof. Nandita Basu, senior author of the study.
The results, which appear in Science, suggest that policy goals for reducing the size of the northern Gulf of Mexico’s dead zone may be unrealistic, and that major changes in agricultural and river management practices may be necessary to achieve the desired improvements in water quality.