Four Greenpeace activists first occupied Brent Spar on 30 April 1995 . In total , 25 activists , photographers and journalists were involved in this stage of occupation . They decided to cover up the Exxon logos on the platform . At this time , activists collected a sample of the contents of the Spar and sent it for testing , to determine the nature of the pollutants which the platform contained . This sample was collected incorrectly , leading to a large overestimate in the contents of the facility . Although Greenpeace quoted Shell 's own estimate of the amount of heavy metals and other chemicals on board , they also claimed there were more than 5,500 tonnes of oil on the Spar – while Shell 's estimate was 50 tonnes . For context , the Exxon Valdez oil spill involved around 42,000 tonnes
Exxon Valdez oil spill
Exxon Valdez oil spill
Brent Spar