The Gulf of Mexico hypoxia monitoring cruise is an annual shelf-wide survey of the Gulf's hypoxic area (i.e., “dead zone”) and the survey is the metric used by the interagency Mississippi River/Gulf of Mexico Hypoxia Task Force to assess progress toward achieving their goal of mitigating hypoxia. Except for 1989 and 2016, this survey has been conducted annually since 1985 and represents one of the longest ecological data sets on record.
Why We Care
The northern portion of the Gulf of Mexico ecosystem, a region containing almost half of the nation's coastal wetlands and supporting commercial and recreational fisheries, has undergone profound changes due to nutrient enrichment of Mississippi River water from land-based sources. This over-enrichment of nutrients stimulates the development of seasonal hypoxia (waters with very low oxygen) over the Louisiana/Texas continental shelf during the summer, and results in the largest recurring hypoxic zone (or “dead zone”) in the United States. Hypoxic waters can cause habitat loss, stress, and even death to marine organisms, affecting commercial harvests and the health of impacted ecosystems. While the size of the dead zone can vary substantially from year to year, the five-year average remains larger than the Mississippi River/Gulf of Mexico Hypoxia Task Force (HTF) goal of reducing the areal extent of the dead zone to less than 5,000 square kilometers.
What We Are Doing
Led by Dr. Nancy Rabalais (Louisiana Universities Marine Consortium [LUMCON]), the survey has historically been part of NCCOS's wider Gulf of Mexico regional competitive research programs: NECOP and NGOMEX.
In Fiscal Year 2015, the survey began to transition to NOAA operations. This project is the next step in that operational transition and provides the extramural scientific support for the FY 2016 cruise. Traditionally conducted using LUMCON's R/V Pelican vessel, funding for 2016 ship time was provided by the NOAA Office of Marine and Aviation Operations for NOAA Ship Nancy Foster.
The goal is for the hypoxia monitoring cruise to become a successful example of how to transition research to operations, while continuing to provide the HTF with its key metric to measure the success of their Action Plan and to continue to support a key forecast of NOAA’s Ecological Forecasting Initiative (i.e., "Roadmap").
NOAA Ship Nancy Foster experienced mechanical engine problems just prior to its Fiscal Year 2016 July hypoxia sampling cruise, resulting in the cancellation of the sampling cruise and only the second time the cruise was not completed since its inception in 1985. A compounding factor was that the depth of the Nancy Foster’s hull (i.e., draft) was too deep to sample the shallower coastal stations, requiring small boat deployments. This requirement and the mechanical setback resulted in NOAA's decision to revert to using University-National Oceanographic Laboratory System (UNOLS) vessels starting in Fiscal Year 2017, specifically, LUMCON's R/V Pelican.
From FY 2017 onward, the annual summer hypoxia sampling cruises have continued successfully under NCCOS sponsorship.