Dead zones are areas of the ocean that no longer have enough oxygen to support sea life. For over 20 years, a dead zone has formed in the gulf due to run off from farms. This year, researchers are worried that the dead zone may increase in size due to the oil spill in the gulf. Microbes consuming oil from the Gulf of Mexico’s BP spill use up oxygen when they die, raising the threat of an expanded dead zone. Scientists are looking at years of dead-zone data to determine whether the dangerous region grew after the spill.

Content produced by National Geographic. Funded in part by the National Science Foundation under Award # DRL-1045744