MDEQ: Reports of ‘oil sheen’ may actually be bacteria

MISSISSIPPI GULF COAST — The Mississippi Department of Environmental Quality advises the public that possible sightings and reports of oil sheen on the Mississippi Gulf Coast after Hurricane Isaac may be naturally occurring iron bacteria, which are not harmful to people’s health or water.

Iron bacteria occur naturally in waterways where they feed on minerals in the water. Some oil-like films, coatings and slimes may look bad but are a natural phenomena. These phenomena are caused by bacteria reacting to the presence of minerals such as iron, manganese, copper, and sulfur in the water.

Bacteria live in wet areas, and may create oil-like films when they attach themselves to the water surface. Sunlight reflects off the films giving them an oily appearance.

To test the difference between a bacterial film and oil floating on the water, break the film.  If the film stays broken, it is a natural bacterial film. If it flows back into place, it is petroleum.

However, it is possible that oil or oily material may be sighted on the Mississippi Gulf Coast, and MDEQ requests that sightings of any oil or oily material be reported to the National Response Center at 1-800-424-8802.