A near record-sized “dead zone” of oxygen-starved water could form in the Gulf of Mexico this summer, threatening its huge stocks of marine life, researchers said. The area could spread to about 8,717 square miles (20,577 square km), scientists at Louisiana State University said on Monday, or about the size of the state of New Hampshire, and larger than the 5-year average of 5,770 square miles. Experts blamed unusually high rainfall across the U.S. Midwest this Spring that washed farm fertilisers along streams and rivers through the Mississippi River Basin out into the Gulf.