Article by: Louise Jett, ljett@lc.edu
GODFREY – The National Great Rivers Research and Education Center (NGRREC℠) and Lewis and Clark Community College hosted the Hypoxia Task Force (HTF) Fall 2014 Public Meeting Oct. 20-22.
The Mississippi River/Gulf of Mexico Watershed Nutrient Task Force holds public meetings twice a year throughout the Mississippi River Basin to inform the public of the progress toward minimizing hypoxia in the Gulf of Mexico.
The Task Force includes five federal and 12 state agencies. The role of the Task Force is to provide executive level direction and support for coordinating the actions of participating organizations working on nutrient management within the Mississippi River/Gulf of Mexico Watershed.
The Task Force has also designated members to a Coordinating Committee that works on activities designated by the HTF members between meetings. Officials discussed a variety of hypoxia-related issued during the public meeting.
Hypoxia is the term for when low oxygen levels occur in bodies of water and is primarily a problem for estuaries and coastal waters at the mouths of rivers. Hypoxia can be caused by a variety of factors, including excess nutrients, primarily nitrogen and phosphorus, delivered from the river’s watershed and water body stratification due to saline or temperature gradients.
Most often, hypoxia occurs when excess nutrients promote significant algal growth. As dead algae decompose, oxygen is consumed in the process, resulting in low levels of oxygen in the water. In some cases, vast stretches of open water become hypoxic and unable to sustain life. These areas are called dead zones and may cause the death of fish, shellfish, corals and aquatic plants.
Nutrients can come from many sources, including fertilizers from agriculture, golf courses and suburban lawns; erosion of soil full of nutrients; discharges from sewage treatment plants; and deposition of atmospheric nitrogen.
The hypoxic zone in the Gulf of Mexico forms every summer and is a result of excess nutrients from the Mississippi River and seasonal stratification (layering) of waters in the Gulf.
During the HTF meeting, Director of the Center for Sponsored Coastal Ocean Research at the National Oceanic and Atmospheric Administration (NOAA) Robert Magnien discussed the Gulf of Mexico hypoxic zone characteristics.
According to the NOAA, the largest Gulf dead zone ever recorded occurred in 2002, encompassing nearly 22,000 square kilometers. The smallest recorded dead zone measured 39 square kilometers in 1988. The average size of the dead zone over the past five years has been about 14,200 square kilometers. The dead zone measured approximately 13,000 square kilometers during the annual hypoxia in survey in July and August of 2014.
NOAA strives to reduce or make significant progress toward reducing the size of the Gulf of Mexico hypoxic zone to less than 5,000 square kilometers by the year 2015 through implementation of action to reduce the annual discharge of nitrogen and phosphorus into the Gulf.
For a complete agenda and links to presentations given during the HTF meeting, visit https://water-meetings.tetratech.com/Hypoxia/StaticPublic/index.htm.