Oil spill response at sea means preventing the spread of oil that has ended up in water, controlling its progress, and recovering it. Such response activity must primarily be carried out as close as possible to the source of the damage, as in that way, response activity is the most effective and the damage to the environment is the smallest.
The most efficient method is to prevent oil or chemical spillage from the vessel at the outset, if possible. After entering the sea, oil forms on the water surface a slick whose thickness depends on the quantity and quality of the oil. Some types of oil and chemicals can fall to the bottom, remain in the water under the surface, or evaporate into the air.
Oil can be recovered or disposed from the sea using three different response methods. Oil can be chemically dispersed by dispersants, incinerated or recovered mechanically using different devices. It has been agreed that only mechanical recovery methods are used in Finland.
Different brush skimmers are typical equipment for oil response. They are used both as large, fixed systems built inside ships and as smaller mobile devices. In addition to recovering oil, it is also important to be able to slow down and steer its spread. This will allow more time for response measures and protect sites with valuable natural values. This is done by using oil booms. Booms floating in the sea can be built into barricades up to several kilometres long. A boom installed between two vessels can also be used to sweep oil.
Air surveillance plays an important role in marine pollution response operations. The majority of the oil contained in an oil slick is located at its thickest point, which is difficult to detect from a vessel on the sea surface. The sensors of a surveillance aircraft and crew members trained to assess oil levels can identify the thickest point and guide the response vessels to the correct location.
Ice conditions make oil spill response more difficult. Finland has developed oil-spill response methods for ice conditions in cooperation with other northern countries. Recovery equipment suitable for ice conditions has been built on the vessels of the Finnish Border Guard and the Finnish Navy.
Finland adheres to the principle which states that the party that caused the damage compensates for the costs incurred in the pollution response. These are recovered from the party causing the damage through insurance policies and international funds. If the party that caused the damage remains unclear, the costs will be reimbursed the State.