Scientists from the National Oceanic and Atmospheric Administration (NOAA) and the Environmental Protection Agency (EPA) have discovered that the dead zone in the Gulf of Mexico is now about the size of Connecticut.
Dead zone, also known as hypoxia, refers to the water area where less oxygen is dissolved, causing marine life to die. It can occur naturally, but humans also contributed to it by allowing wastewater to flow into the rivers and coasts. Aside from the Gulf of Mexico, there are also dead zones in the East Coast and the Great Lakes.
The researchers mapped the gulf's dead zone and found out that the area with low oxygen water measured around 5,052 miles for this year's summer. The measurements used in developing the map were taken from July 27 to Aug. 2, during the 30th annual hypoxia survey cruise.
The recorded size for this year is a bit smaller than the 5,840 miles recorded for 2013, indicating an improvement. Yet, the Mississippi River/Gulf of Mexico Watershed Nutrient (Hypoxia) Task Force felt disappointed because it is below their target reduction, which was set at 1,900 square miles. This measurement reflects that the nutrients from the Mississippi River watershed are continuously running off and depleting the resources present in the Gulf.
The task force is composed of members from at least five federal agencies, along with 12 states and tribes that live near the river.
The largest dead zone to be recorded in the Gulf was in 2002, and it measured at least 8,841 square miles; the smallest dead zone was recorded in 1988 and measured 15 square miles. For the past five years, the average size of the Gulf of Mexico dead zone is 5,500 square miles.
"The Mississippi River discharge levels and associated nutrient data, supplied in May by the USGS, pointed to an average size hypoxia area based on the inputs which fuel mid-summer's dead zone algal growth," said Nancy Rabalais, Ph.D., executive director of the Louisiana Universities Marine Consortium (LUMCON).
The yearly mapping and measurement of the Gulf's dead zone provides scientists with data to map the dead zone of the Gulf of Mexico. The annual survey is also used to measure the progress of the efforts implemented to reduce its size.
