Two large oil spills and four medium oil spills were reported in 2017 according to the International Tanker Owners Pollution Federation (ITOPF) in its latest report. The first large spill was last June when Rama 2 sank in the Indian Ocean with more than 5,000 tonnes of oil on board. The second incident involved tanker Agia Zoni II, which sank off the coast of Greece in September, spilling about 700 tonnes of oil, some of which washed up on luxury beaches near Athens – significantly raising the profile and political implications of the event.
Of the four medium-sized spills last year, two occurred in January in South Asia and Southeast Asia, both of them resulting from collisions that generated the leaking of bunker fuel.
A third spill, also involving bunker fuel, occurred in East Asia in August. This was the result of a vessel grounding in bad weather. The fourth medium-sized spill occurred in the US last October.
The total volume of oil lost to the environment in 2017 was recorded at about 7,000 tonnes, the majority of which was the result of the Rama 2 event in the Indian Ocean.
“It is interesting to note that the progressive reduction in the number of large spills is significant when data is analysed per decade rather than annually. Data recorded from 1970 to 2017 illustrate fluctuations in the yearly values within a decade”, ITOPF said.
There had also been a decline in the number of medium-sized spills (from 7 to 700 tonnes). The average number of spills per year in the 1990s was 28.1, reducing to 14.9 in the 2000s and 4.9 for the 2010s to date.
ITOPF said that, while increased tanker movements might imply increased risk, it was encouraging to observe that the downward trend in oil spills continued, despite an overall increase in oil trading over the period.
For large spills the yearly average was around 25 in the 1970s, but has been reduced to less than two since 2010.
For 2010-2017 there had been 53 spills of 7 tonnes and over, resulting in 47,000 tonnes of oil lost, with 80% spilled in just 10 incidents. However, the Sanchi event earlier this month (111,700 tonnes) will fat-tail skew the figures for this decade, as well as significantly raising the overall average.
Between 1970 and 2017, a half of large spills occurred while the vessels were underway in open water. Allisions, collisions and groundings accounted for 59% of causes. When a spillage occurred while a vessel was underway in inland or restricted waters, allisions, collisions and groundings were linked to some 99% of spills.
Referring to the Sanchi event, ITOPF said that “accidents still happen, as demonstrated on January 6th by the tragic incident that occurred off the coast of China involving the oil tanker Sanchi. Learning lessons from incidents such as these will assist tanker owners and governments to continue to work together to reach the highest level of safety and environmental stewardship,” ITOPF said.