Leopold Center for Sustainable Agriculture

Iowa Water Conference focuses on urban, rural water quality

Back to Leopold Letter Spring 2012

A growing number of hypoxic zones in the world means that Iowa is not alone in efforts to reduce nutrient loads in streams to improve water quality in the Gulf of Mexico. However, Iowa and other states in the Mississippi River basin may need to double their efforts to achieve water quality goals set 10 years ago.

“The continental shelf is more sensitive to the same amount of nutrient load so it is harder to make changes as these systems become embedded,” said Louisiana State University researcher Gene Turner, who has been measuring the hypoxic zone in the Gulf each June since 1985. “An additional problem is that we have lost 2,000 square miles of wetlands on the Louisiana coast.”

Turner was a keynote speaker at the annual Iowa Water Conference March 6-7 in Ames.  The Leopold Center is a partner in the event that combines groups from agriculture and environment, flood plain management, the Iowa Learning Farms, stormwater and water monitoring. The goal of the conference is to create greater awareness of Iowa urban and agricultural water issues through sustainable watershed management.

Hypoxia is a low-oxygen zone in coastal waters, caused by excess nutrients that promote algae growth. Oxygen is consumed when algae die and decompose, creating areas that are unable to sustain life. Along the Louisiana coast, home to about one-third of U.S. fisheries, the hypoxic zone reduces shrimp populations, which also rely on wetlands in the estuary for reproduction. Boats also must travel further to reach fish that have been able to move to deeper waters.

Turner said the size of the Gulf hypoxic zone is determined by the Mississippi River nitrogen concentration in May. Last year, flooding in the Missouri River basin contributed to a larger volume of water, but nitrogen concentration was lower so the zone was smaller than predicted. The zone has continued to grow each year to about the size of Lake Erie. Warmer ocean currents also are affecting expansion of the system.

Turner thought some of the estimated $21 billion in fines from the 2010 BP oil spill should be used in the upper Mississippi River basin to demonstration agricultural practices that reduce nutrient load to streams. “It would be a way to integrate our value system on a watershed basis,” he said.

Iowa Secretary of Agriculture Bill Northey followed Turner with an update on the Iowa Nutrient Reduction Initiative. The initiative began in 2010 with an assessment of the science related to nutrient reduction and water quality. Northey expected that a preliminary report will be available this summer. The next step will be recommended strategies and practices that farmers can use in their operations.

“This will be a turning point,” he said. “We will spell out what we want to put on the ground and make it easy and safe for farmers to be involved.” He said the approach will be voluntary and similar to soil conservation efforts, which many farmers have adopted “because they work.”

Back to Leopold Letter Spring 2012