When she wasn't analyzing air samples, HOUSTON CHRONICLE reporter Dina Cappiello was investigating another environmental crisis: the Dead Zone. It's a giant swath of ocean in the Gulf of Mexico where oxygen drops so low that it is unable to support some marine life. The Dead Zone forms each summer due to the fertilizer and wastewater runoff that makes its way to the Gulf via North America's rivers. The nutrient overload causes an excessive algae bloom -- when the algae die and decompose, they use up all the oxygen in a particular area. All oxygen-breathing marine life in the zone must flee or die. The Dead Zone changes each year, but can be as large as the state of New Jersey. There are other dead zones around the world.

Cappiello spent a week aboard a research vessel with scientists on the hunt for the Dead Zone. Read her blogs from the journey here.