Achieving water quality goals for the Gulf of Mexico may take decades, according to findings by researchers at the University of Waterloo.
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.
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.
“Despite the investment of large amounts of money in recent years to improve water quality, the area of last year’s dead zone was more than 22,000 km2–about the size of the state of New Jersey,” said Kimberly Van Meter, lead author of the paper and a postdoctoral fellow in the Department of Earth and Environmental Sciences at Waterloo.
Using more than two centuries of agricultural data, the scientists show that nitrogen has been accumulating in soils and groundwater over years of intensive agricultural production and will continue to make its way to the coast for decades.