Hypoxia, fertilizer and the Gulf of Mexico

© 2001 Eugene S. Takle

Recent news reports in the scientific literature have generated substantial discussion in letters to the editor. Dan Ferber's article in the 9 Feb 2001 (p. 968) of Science generated 4 letters in the 25 May 2001 (p. 1485) issue. The size of the Gulf's dead zone peaked in 1995 at about 18,000 km2 and then dropped in 1996, 97, and 98. Then in 1999 it expanded to about 19,000 km2 before dropping precipitously to about 4,000 km2 in 2000. Natural fluctuations along with variations in fertilizer inputs and weather conditions that lead to fertilizer loss from soils evidently are leading to large uncertianties in our ability to quantify the problem and define strict cause-effect relationships.