The environmental impact of millions of gallons of oil still in the Gulf of Mexico from the Deepwater Horizon incident may depend on microscopic helpers: Bacteria that consume oil and other hydrocarbons and could break down the spilled crude, making it disappear, as highlighted in the current issue of Chemical & Engineering News (C&EN).
The author points out that the oil-eating bacteria are beneficial in helping to clear away the oil. Their activity, however, could eventually pose risks to the Gulf's ecosystem, particularly in the deep ocean. The oil acts as a huge source of food and could produce bacteria "blooms," or massive population explosions. As the blooms die and decay, they remove oxygen from the Gulf water, jeopardizing the health of fish and other aquatic animals.
The article discusses scientific research underway to shed light on the bacteria's effects. It notes that the oxygen depletion so far is not as serious as the Gulf of Mexico's infamous "dead zone," an 8,000 square mile area — about the size of New Jersey — with oxygen levels too low for fish to survive. The Gulf's oil plumes cause nearly a 35 percent oxygen drop compared to a 90 percent drop in that dead zone.