This improvement continued into the 1990s, with the figure falling to an average of just over seven per year. Yet ISU salvors continue to assist casualties which threaten serious pollution. The event produced a major spill. Salvage, as a means of pollution defence, may also involve the removal of bunkers and polluting cargoes from vessels which have been declared total losses. Increasingly, salvors have entered into partnership arrangements with governments, to provide pollution defence services.
Many governments now favour standby salvage arrangements.
These retainers have the advantage of providing a guaranteed level of protection for busy waters - such as the English Channel and Dover Strait. Many ISU salvors now participate in standby agreements. Arrangements are in place in a number of countries, including the UK, France, Spain, Germany, Italy, the Netherlands and South Africa. A salvage tug on Coastguard patrol. In some parts of the world, there is growing concern over the threat posed by elderly wrecks.