Gulf of Mexico Hypoxia Watch CTD Station Locations for SEAMAP Cruises of 2001 - 2023

The NOAA Hypoxia Watch project provides near-real-time, web-based maps of dissolved oxygen near the sea floor over the Texas-Louisiana-Florida continental shelf during a period that extends from early June to mid-July. In 2008 there was a Fall Hypoxia Watch Cruise in October and November. The NOAA National Marine Fisheries Service Mississippi Laboratories at Pascagoula and Stennis Space Center and the NOAA National Centers for Environmental Information (NCEI) began the Hypoxia Watch project in 2001. Scientists aboard the NOAA Research Vessel Oregon II measure seawater properties, such as water temperature, salinity, chlorophyll, and dissolved oxygen at each of approximately 240 locations as the Oregon II cruises the waters from Brownsville, Texas, to the mouth of the Mississippi River, then into Florida waters. A scientist aboard the ship processes the measurements from electronic dissolved oxygen sensors, checks the measurements periodically with chemical analyses of the seawater, then sends the data by e-mail to NCEI at Stennis Space Center approximately every three to five days. Personnel at NCEI transform the dissolved oxygen measurements into contour maps, which identify areas of low oxygen, or hypoxia. During the 6-week cruise, as the data is received from the ship, NCEI generates new maps and immediately publishes them on the web. The first map will usually cover an area near Brownsville, TX, then gradually areas along the Texas, Louisiana, and Florida coasts will be added. Maps are published every three to five days from approximately June 10 to July 20.