Hypoxia occurs when the amount of oxygen in water becomes too low to support most aquatic life (typically below 2 mg/L). Hypoxia is an expanding global problem and a symptom of degraded water quality, largely resulting from human activities such as agricultural runoff, burning of fossil fuels, and wastewater treatment discharges. Hypoxic waters can become dead zones for organisms that cannot escape. This directly impacts ecosystem health, and often reduces the value of commercial and recreational fisheries. The majority of NOAA’s efforts to understand and reduce hypoxia in U.S. coastal waters are supported through the NCCOS Competitive Research Program.

Hypoxia Forecasting

To achieve these activities, NCCOS supports a Hypoxia National Office at the Northern Gulf Institute, a NOAA Cooperative Institute. This office advances research and management of hypoxia in the Gulf of Mexico and addresses NOAA mandates under the Harmful Algal Bloom and Hypoxia Research and Control Act. The Hypoxia National Office works with NOAA to provide technical assistance, observations and monitoring, coordination, and the science underpinning the management of the annual hypoxic zone in the Gulf of Mexico.

NCCOS and the Mississippi River/Gulf of Mexico Watershed Nutrient Task Force

NCCOS supports NOAA’s role in the Task Force, which is charged with collaboratively reducing and controlling the Gulf of Mexico dead

zone, the largest hypoxia area in the U.S. We support the Task Force by:


Producing the annual forecast predicting the size of the annual dead zone.


Conducting the annual survey to measure the size of the hypoxic zone in the Gulf of Mexico, a key metric used by the Task Force to measure the progress of nutrient reduction targets in the Mississippi River watershed.


Providing a retrospective analysis with two coupled hydrodynamic-biogeochemical models at the end of each hypoxic season for the Task Force on the dynamics of hypoxia during the past season.

Coastal Hypoxia Research Program

The Coastal Hypoxia Research Program is an NCCOS competitive research program focused on advancing the understanding and management capabilities to assess, predict, and reduce hypoxic events and their environmental impacts on our nation’s oceans, estuaries, coasts, and Great Lakes ecosystems. This program is authorized by the Harmful Algal Bloom and Hypoxia Research and Control Act (HABHRCA), 33 U.S.C. §4001–4009.

The overall goal of the Coastal Hypoxia Research Program is to improve the ability of resource managers to effectively prevent or reduce the ecological and economic impacts of hypoxia on marine and Great Lakes ecosystems. Prevention or reduction of hypoxia requires a fundamental understanding of the causes and consequences of hypoxia and tools to evaluate the effectiveness of management strategies. This program provides research results and modeling tools for resource managers to assess alternative management strategies to address hypoxia in ecosystems and make proactive and informed decisions. Research topics include: determining the causes of hypoxia; developing the capability to predict its occurrence in response to varying levels of anthropogenic stresses; and evaluating the subsequent ecological, economic, and social impacts of hypoxia.

Gulf of Mexico Hypoxia Impact Studies

The northern Gulf of Mexico contains almost half of the nation's coastal wetlands and supports commercial fisheries generating one billion dollars annually. Hypoxic waters prevalent during the summer can cause habitat loss, stress, and even death to marine organisms, affecting commercial harvests and the health of impacted ecosystems. Current studies are documenting the dynamics of the hypoxic zone over the Louisiana continental shelf, including its extent, the processes that influence its development, and its impact on fisheries.

Take a Closer Look: Environmental Interactions

We are assisting coastal managers and aquaculture farm operators with the development of environmental monitoring protocols for marine aquaculture, which will support sustainable development of the aquaculture industry. Monitoring is a powerful tool for ensuring aquaculture activities are conducted with minimal long-term impacts to marine ecosystems. The best monitoring protocols provide a standardized guide for the collection of data to reflect environmental trends around a farm, without placing undue burden on farm operators.

Learn more about multi stressor impacts to ecosystems including hypoxia