Mauritius is preparing itself for an environmental catastrophe after a Japanese-owned tanker ran aground in its pristine waters. The stricken MV Wakashio has already leaked around 1,000 metric tons of oil and there are fears that it could break in two, spelling disaster. Salvage teams have detected serious cracks in the vessel’s hull and they are now racing to remove approximately 2,000 tons of oil from its remaining undamaged tanks before it breaks up.

While the volume of oil onboard the tanker is substantially lower than history’s worst spillages, it could still prove enormously damaging for Mauritius and its delicate maritime ecosystem. This infographic uses data from the International Tankers Owners Pollution Federation to illustrate the volume of oil lost in the worst tanker spillages down through the years.

The worst disaster by volume occurred in 1979 when the Atlantic Empress collided with the Aegean Captain, another fully laden tanker, during a storm 33km off the coast of Tobago. The vessel eventually sank, losing 287,000 tons of oil. In recent years, oil transport by sea has become significantly safer and there are 92 percent fewer accidents since the 1970s.