Combatting oil at sea/Protecting Sensitive Areas

Combatting Oil at Sea

Oil combat at sea is the best method to prevent wildlife coming into contact with the oil. At first the efforts are focused on containing the oil at or close to the source, which is often a ship. If these efforts do not solve the problem and oil is drifting away from the source, there are a number of techniques to combat the oil at sea, the most important described briefly below.

Mechanical methods

Offshore booming

Booms are floating devices that can be placed in the water to prevent oil from moving. Booms can be joined together if greater length is needed. Different types of boom are used depending on conditions but each has  limitations. For offshore booming, two ships tow a specieally designed boom which collects oil. The collected oil is removed from the water by one of the ships using a skimmer.

Specially designed ships Sweeping arms are placed on the sides of ships, which then travel through the oil slick. The arms move the oil to the sides of the ships where it is removed drom the water by skimmers. The ships have large storage tanks, sometimes heated to keep the oil in a liquid state, which enable them to collect large quantites oil before they have to return to shore.

Chemical methods

Dispersants

Dispersants are chemicals that are sprayed over a slick of fresh oil. The chemicals force the oil into the water column where it is broken down into small droplets. The small droplets enhance the process of biodegradation.

 

Other methods

In situ burning

The method of offshore booming is used, but this time with fire resistant booms. When enough (fresh) oil has been collected it can be set on fire. The lightest components of the oil will burn, while heavier components will not burn but rather sink to the bottom.

Protecting Sensitive Areas

Sensitive areas, such as vulnerable coastal habitats, can be protected from oil pollution, although the effectiveness of this protection will depend very much on sea and weather conditions, and characteristics such as currents and tides. A very important method of preventing oil from reaching the shoreline is protection booming. In this case, rather than collecting the oil, the booms are used to stop the oil from reaching the sensitive areas. High winds, big waves and strong currents may make this method ineffective.