The gulf of mexico provides 72 percent of the shrimp harvested in u. s. waters. those populations are at risk because the dead zone in the gulf of mexico. which statement best described this dead zone? a. it is a zone that formed when it lost its keystone species b. it is a zone of ocean water that has almost no oxygen c. it is a zone that’s been depleted by sea urchins d. it is a zone of ocean water that has almost no carbon dioxide