A lifetime of research links Gulf of Mexico ‘dead zone’ to Midwest fertilizer runoff – Columbia Missourian

Global areas of hypoxia: Global map of low and declining O2 levels in the open ocean and coastal waters from Breitburg et al. (2018) (Map created from data provided by R. Diaz, updated by members of the GO2NE network, and downloaded from the World Ocean Atlas 2009., CC BY-SA 4.0 via Wikimedia).

In the summer of 1985, Nancy Rabalais set sail on a research vessel into the Gulf of Mexico — and into the scientific unknown.Back then, scientists knew little about wide expanses of low-oxygen water, called hypoxia…That summer, Rabalais’ team was set on discovering how these areas connected to creatures that dwell on the bottom of the Gulf. While analyzing water and sediment samples miles off the coast, the team from the Louisiana Universities Marine Consortium and Louisiana State University quickly discovered that hypoxia stretched from the Mississippi River to Texas — and that it lasted for most of the summer…

Expanding Hypoxic Areas in Coastal Waters

Unnatural levels of hypoxia, which occur mostly in the summer, are primarily the result of human activities that deliver nutrients such as nitrogen and phosphorous into waterways.