Biological agents are chemicals or organisms that increase the rate at which natural biodegradation occurs. Biodegradation is a process by which microorganisms such as bacteria, fungi, and yeast break down complex compounds into simpler products. Biodegradation of oil is a natural process that slowly removes oil from the aquatic environment. However, rapid removal of spilled oil from shorelines and wetlands is necessary in order to minimize potential environmental damage to these sensitive habitats.

Bioremediation technologies can help biodegradation processes work faster. Bioremediation refers to the act of adding materials to the environment, such as fertilizers or microorganisms, that will increase the rate at which natural biodegradation occurs. Two bioremediation technologies that are currently being used in the United States for oil spill cleanups are:

• Fertilization - the method of adding nutrients such as phosphorus and nitrogen to a contaminated environment to stimulate the growth of the microorganisms capable of biodegradation; and
• Seeding - the addition of microorganisms to the existing native oil-degrading population. As with fertilization, the purpose of seeding is to increase the population of microorganisms that can biodegrade the spilled oil.

For additional information on bioremediation, view the following documents:

• Nation Response Team fact sheet on Bioremediation Technologies
• Guidelines for the Bioremediation of Marine Shorelines and Freshwater Wetlands
• Aerobic Biodegradation of Oily Wastes - A Field Guidance Book For Federal On-scene Coordinators
• Guidelines for the Bioremediation of Oil-Contaminated Salt Marshes
• Literature Review on the Use of Commercial Bioremediation Agents for Cleanup of Oil-Contaminated Estuarine Environments