Graph of the Day: Size of Hypoxic Zone in the Gulf of Mexico, 1977-2007

The relationship between the size of the hypoxic zone in July (km2) and the May nitrate+nitrite N loading (kg N) to the Gulf of Mexico each year. A linear regression of the data is shown. The individual data points are in four chronologically-sequenced groups separated from each other when the data fall below the slope, and whose separation is coincidental with hurricane events. From Turner et al. (2008).

2009 Forecast of the Summer Hypoxic Zone Size, Northern Gulf of Mexico [pdf]