Updated

Federal scientists are predicting an average dead zone this summer in the Gulf of Mexico. But they note that this would still be three times greater than the long-term goal for reducing the size of the area where there's too little oxygen to support marine life.

The National Oceanic and Atmospheric Administration predicts this year's will cover about 5,780 square miles (15,000 square kilometers), or about the size of Connecticut. The 33-year average is about 5,460 square miles (14,100 square kilometers).

Last year's was the largest ever measured, at 8,776 square miles (22,720 square kilometers).

NOAA says it's making independent predictions for the first time, after years of working with four universities.

The forecast is based on nitrogen runoff and river discharge data from the U.S. Geological Survey.