Recognition of spilt oil at sea or on the shoreline may be the first indication of an oil spill. Depending on the quantity and type of oil involved, a clean-up response may have to be organised for removing the oil and protecting sensitive areas nearby.
The fate of spilt oil depends on a number of factors, such as the amount of oil spilled; its initial physical and chemical characteristics; the prevailing weather and sea conditions; and whether the oil remains at sea or comes ashore.
Once spilled at sea, the natural tendency for the oil will be to spread, break up and become dissipated over time. This dissipation is a result of a number of chemical and physical processes acting on the spilt oil. These processes are collectively referred to as weathering.
In considering the fate of spilled oil at sea and potential clean-up and response techniques, the persistence of the oil in the environment should be taken into account.
A variety of models exist which may be used to aid in decision making processes and forecasting the likely locations the oil may strand. Models can be used at a contingency planning stage, allowing stakeholders to envisage a variety of scenarios and their likely outcome, as well as during a real-time spill to aid clean-up and response decisions.
The effect of oil spills can be far reaching, posing both an environmental and economic threat. Recreational activities, local industry, fisheries, and marine life are among the resources that can be adversely affected by oil spills.
The recovery of the environment after a spill depends on a variety of factors such as the type and amount of oil spilled; the biological and physical characteristics of the affected area; time of year and weather conditions, and notably the clean-up and response strategy used. Typical environmental impacts range from toxicity to smothering effects.
Spills of chemicals and other Hazardous and Noxious Substances (HNS) may also present a threat to the environment. The behaviour and fate of spilled HNS will depend on its chemical and physical properties. Its impact will also vary according to local conditions.