Articles | Volume 11, issue 1
Hydrol. Earth Syst. Sci., 11, 191–209, 2007
https://doi.org/10.5194/hess-11-191-2007

Special issue: A view from the watershed revisited

Hydrol. Earth Syst. Sci., 11, 191–209, 2007
https://doi.org/10.5194/hess-11-191-2007

  17 Jan 2007

17 Jan 2007

Marine modification of terrestrial influences on Gulf hypoxia: Part II

E. C. Krug and K. Merrifield E. C. Krug and K. Merrifield

Abstract. This study examines potential marine modification of two classes of terrestrial influence on Gulf hypoxia: (1) the flow of nutrient-rich water from the Mississippi/Atchafalaya River Basin and (2) the massive physical, hydrological, chemical and biological change associated with the Atchafalaya’s partial capture of the Mississippi River. The latter involves repartitioning of a total flow of about 20 000 m3 sec−1, equal to that of 13 Nile Rivers, and a sediment load of 210 million metric tonnes yr−1,nearly 20 times that delivered by all of the rivers of the East Coast of the USA. Also involved is the loss of hundreds-to-thousands of years of stored nutrients and organic matter to the Gulf from enormous coastal wetland loss. This study found that the oceanography of the Gulf minimises the impact of both classes of terrestrial influence from the Mississippi River and its nearby estuaries on Gulf hypoxia. Oceanographic conditions give events associated with the Atchafalaya River a disproportionately large influence on Gulf hypoxia. A truly holistic environmental approach which includes the full effects of this highly dynamic coastal area is recommended to better understand and control Gulf hypoxia.