Scientists with LSU and the National Oceanic and Atmospheric Administration say this year’s “dead zone” in the Gulf of Mexico is predicted to be 8,800 square miles, the largest recorded in history.

Scientists have been measuring the dead zone in the Gulf since 1985.

The zone is an area of hypoxia — low-oxygen water that cannot support marine life — that forms each summer. Scientists blame nutrients from fertilizer or urban runoff into the Mississippi River. The nutrients wind up in the Gulf, where they contribute to algae growth. After the algae dies, it sucks up oxygen as it decays.

LSU scientist R. Eugene Turner said Tuesday that the predicted record “dead zone” will be largely caused by nitrogen from fertilizer running into the Mississippi River from a huge increase in corn planting for ethanol production.

The dead zone forces fishermen to go farther out in the Gulf and to different places to find fish, raising their costs for fuel, Turner said.

The scientists’ forecast was released Tuesday during a midday telephone news conference. It is based on a mathematical model developed by LSU through NOAA research

The largest “dead zone” on record was in 2002 with a measurement of 8,481 square miles, according to a NOAA news release.

Tuesday’s prediction will be field-tested when Nancy Rabalais of the Louisiana Universities Marine Consortium measures the actual size of the dead zone in late July.