Scientists say the Gulf of Mexico area with too little oxygen to keep sea creatures alive is the 11th largest measured and nearly 18 percent bigger than predicted. It stretches into Texas waters.
They say the reason is that heavy June rains throughout the Mississippi River watershed carried nutrient-rich runoff from farms and other human activities into the gulf.
Nancy Rabalais of the Louisiana Universities Marine Consortium says the dead zone is about as big as Connecticut plus Rhode Island, covering 6,474 square miles.
The National Oceanic and Atmospheric Administration had predicted it would cover nearly 5,500 square miles, based on combining four models. The highest of those four predictions was low by nearly 500 square miles.
Last year's dead zone was about the size of Connecticut.