Bacteria can be used to clean up oil spills in the ocean through bioremediation. Bioremediation is any process that uses decomposers and green plants, or their enzymes, to improve the condition of contaminated environments. Specific bacteria can be used to bioremediate specific contaminants, such as hydrocarbons, which are present in oil and gasoline.
Oil spills in the ocean have a severely negative effect on marine life, especially seabirds and filter-feeders. Seabirds, such as seagulls and ducks, spend most of their life on water and go to land only during their nesting period. The feathers of many seabirds are wettable and must be carefully preened (or dried) for flight. If feathers come into contact with oil, the seabird ingests the oil while trying to preen. Filter-feeders, such as clams and oysters, take in surface water through their gills and filter it to take out any microscopic food. If there is oil on the water, it gets concentrated within these shellfish and then accumulates in their predators in a higher concentration.
In this demonstration, soap is used to mimic the effect of bioremediation by bacteria by minimizing the area of the surface covered by oil. Oceanic oil spills are managed using containment methods that float on the water and bioremediation (adding bacteria to the oil to speed up the breakdown process).