In 2014, the "dead zone" in the Gulf of Mexico was found to have shrunk to the size of Connecticut. To the ire of environmentalists, it has since ballooned to its largest size since mapping began in 1985, says NOAA. Covering 8,776 square miles—that's the size of New Jersey—the low-oxygen zone is now more than 3% larger than 2002's record-setting size of 8,497 square miles, mostly due to heavy rains in the Midwest that increased agricultural runoff this year, reports Time. The equivalent of 2,800 train cars of fertilizer was carried into the Gulf in May alone, reports National Geographic. Once there, nitrogen and phosphorus from fertilizers trigger algae blooms that suck up oxygen in the water as they die, leaving too little for fish and other marine life to survive, per NPR.
Researchers say the zone is even larger than the numbers indicate because time constraints meant the whole thing couldn't be mapped and winds have been helping to compress it. That's despite a task force that's working to shrink the zone to 1,950 square miles by 2035. That would require a 59% reduction in the amount of nitrogen flowing into the Mississippi River, yet "river nitrate concentrations have not declined since the 1980s," researchers write in Proceedings of the National Academy of Sciences. A separate study from environmental group Mighty Earth blames our "factory farm system," per Inhabitat. A Mighty Earth rep says "companies' practices need to be far more sustainable. And a reduction in meat consumption is absolutely necessary to reduce the environmental burden." (These are America's most endangered rivers.)