By Marguerite Huber
Hypoxia sounds like some sort of deadly disease. While it is not a disease, it is in fact deadly. Also referred to as dead zones, hypoxic water kills bottom-dwelling marine life such as crabs and mussels. (To learn more, see the video at the end of this blog.)
Dead zones lack dissolved oxygen and are caused primarily by excess nutrients such as nitrogen and phosphorous. Too many nutrients cause algae and plankton to grow in large numbers, and as the algae die and decompose, oxygen is consumed.
Excess nutrients are especially a problem in the Gulf of Mexico. Every summer, nutrient-rich freshwater from the Mississippi River flows into the Gulf, resulting in a dead zone of about 7,772 sq. mi. that causes massive fish kills and chases other creatures further out to sea.
In an effort to understand this annual occurrence, EPA researchers have developed a modeling framework for predicting how nutrient management decisions and future climate change scenarios will impact the size, frequency, and duration of hypoxic conditions that form in the Gulf of Mexico every summer.
Providing 17% of the Nation’s gross domestic product, the natural resources of the Gulf’s coastal and marine habitats and their ecosystem services are critical to both the regional and national economy. That’s a major reason why EPA researchers are exploring ways to improve and restore Gulf water quality and aquatic habitats.
Since the 1990’s, the Agency and its partners from coastal states have been monitoring estuaries and most recently, wetlands. This baseline came in handy in the aftermath of Hurricane Katrina and the BP oil spill, and it will continue to help researchers track the degree of recovery resulting from ongoing and future restoration actions in the Gulf.
Monitoring in the future will also help inform environmental management decisions by addressing linkages between ecosystem condition and the goods and services provided. Agency researchers have several methodologies in development for examining these linkages, including spatial analysis tools, and human well-being indices.
About the Author: Marguerite Huber is a Student Contractor with EPA’s Science Communications Team.