NOAA just predicted that a large dead zone, about the size of Massachusetts, will develop in the Gulf of Mexico this summer as a result of record rains and flooding in the Midwest. Meanwhile, flooding and fast currents have stalled most of the barge traffic on the Mississippi, with almost 300 barges waiting out the weather at two locks there. NOAA says the dead zone, an area where low or no oxygen can kill fish and other marine life, will be caused by nutrient pollution flowing down the Mississippi. Once the excess nutrients reach the Gulf, they will stimulate the…