The Harmful Algal Bloom and Hypoxia Research and Control Act (HABHRCA) mandates the development of scientific tools for natural resource managers to address hypoxia in coastal ecosystems. In response, NCCOS has supported development of scenario forecast models in many U.S. coastal regions that experience severe hypoxia, with the most mature of these efforts focused in the northern Gulf of Mexico and the Chesapeake Bay.
Why We Care
Hypoxia, or low dissolved oxygen, occurs when the amount of dissolved oxygen in water becomes too low to support most aquatic life (typically below 2 mg/l). Hypoxia is a globally expanding problem affecting aquatic ecosystems, and, although hypoxia can occur naturally, it is often a symptom of degraded water quality resulting from human activities (e.g., nutrient pollution). Common sources of nutrient pollution include agricultural runoff, the burning of fossil fuels, and wastewater treatment discharges. Over half of all U.S. estuaries experience natural or human-induced hypoxic conditions at some time each year, and the frequency and duration of hypoxic events have increased over the last few decades.
What We Are Doing
In both the Gulf of Mexico and Chesapeake Bay, NOAA and its partners are using statistical models to inform regional management entities of progress toward hypoxia reduction goals. The models also play a crucial role in raising public and stakeholder awareness of the hypoxia problems and the actions needed to address them, an essential element of a successful management plan.
For the northern Gulf of Mexico, these statistical models are the primary management tool to guide nutrient loading targets to reach the interagency Mississippi River/Gulf of Mexico Hypoxia Task Force's goal to reduce the size of the hypoxic zone to 5,000 square kilometers.
For the Chesapeake Bay, the models compute the volume and duration of hypoxia based on data collected by the states of Maryland and Virginia and the U.S. Geological Survey. The results help scientists and natural resource managers determine possible impacts to bay life and provide information on the reductions needed to manage nutrient loads coming into the bay.
Primary researchers involved in this modeling project include, in alphabetical order, Bill Dennison (UMCES), David Forrest (VIMSS), Dan Obenour (N.C. State), Don Scavia (U. Michigan), Jeremy Testa (UMCES), and R. Eugene Turner (LSU). Major collaborators include Marjorie Friedrichs (VIMS), the Chesapeake Bay Program. and the states of Maryland and Virginia.
Hypoxia modeling and forecasts are supported through the NCCOS Northern Gulf of Mexico Ecosystems & Hypoxia Assessment (NGOMEX) and Coastal Hypoxia Research (CHRP) programs. The goal for NCCOS-supported hypoxia models is eventual transfer to an agency or organization for financially independent and routine operational hypoxia forecasts.