You are here:
DEVELOPING AN INTEGRATED ASSESSMENT OF HYPOXIA IN THE NORTHERN GULF OF MEXICO
Citation:
SchubauerBerigan, J, H K. Austin, M. L. Belefski, AND L. TerveltNorton*. DEVELOPING AN INTEGRATED ASSESSMENT OF HYPOXIA IN THE NORTHERN GULF OF MEXICO. Presented at SETAC, Nashville, TN, 11/1/2000.
Description:
Hypoxia is the condition in which dissolved oxygen levels are below that necessary to sustain most animal life. The largest zone of oxygen depletion in the US coastal waters is found in the northern Gulf of Mexico (NGOM) on the LA/TX continental shelf. In response to growing public concerns, EPA participated in a Federal interagency effort (under the Office of Science and Technology Policy) to develop an integrated assessment (IA) of the causes and consequences of hypoxia in the NGOM. We describe the process to develop the IA (based on a series of 6 peer-reviewed scientific reports) and review it's significant findings. Hypoxia in the NGOM is caused primarily by excess nitrogen from the Mississippi-Atchafalya River Basin in combination with stratification of Gulf waters. River nutrient flux has increased significantly since the early 1900's, due to major changes in the Basin such as landscape alterations (deforestation and artificial agricultural drainage), river channelization (flood control and navigation), and dramatic increases in fertilizer nitrogen input. We review results of modeling approaches to improve nitrogen management, including agricultural N management and wetland and riparian buffer restoration. The results of the IA and other scientific information will be used by the Mississippi River/Gulf of Mexico Watershed Nutrient Task Force to develop a plan of action to reduce, nitigate, and control hypoxia in the NGOM. The IA significiantly advances scientific understanding of hyposia in the NGOM, but specific scientific uncertainties remain. We discuss both the research priorities required to reduce uncertainties and next steps towards completing the Action Plan.