Water Protection Program
Missouri Nutrient Reduction Strategy Committee
The coastal goal of the Gulf Hypoxia Action Plan 2008 is stated as follows: “Subject to the availability of additional resources, we strive to reduce or make significant progress toward reducing the five-year running average areal extent of the Gulf of Mexico hypoxic zone to less than 5,000 square kilometers by the year 2015 through implementation of specific, practical and cost-effective voluntary actions by all federal agencies, states, and tribes, and address all categories of sources and removals within the Mississippi/Atchafalaya River Basin to reduce the annual discharge of nitrogen and phosphorus into the gulf.” This goal would restore the gulf to conditions that likely existed prior to the mid 1970s when large hypoxic zones began appearing annually in the Louisiana – Texas continental shelf region.
The size of the hypoxic zone varies considerably each year, depending on natural and anthropogenic factors. In 2012, as a result of the severe drought conditions in the Midwest, the measured size of the hypoxic zone was 7,480 square kilometers (2,888 square miles), or an area about the size of the state of Delaware, and the 4th smallest hypoxic zone since measurements began in 1985. However, the current five-year running average (2008 to 2012) is 14,744 square kilometers (5,693 square miles), which is nearly three times larger than the coastal goal. Thus, considerable work still remains in reducing nutrient loads within the basin.