This summer’s dead zone in the Chesapeake Bay could end up being one of the smallest of the last 25 years. The University of Maryland’s Center for Environmental Science is predicting the fifth smallest dead zone, which is a stretch of water lacking the oxygen needed for fish and shell fish to breathe. A wide variety of pollutants are a big reason the dead zone exists every year. It’s usually found in a stretch of water bounded by the bay bridge to the north and the mouth of the Potomac River to the south.