Wreck sunk over a century ago, found leaking fuel in Baltic Sea

TALLINN - The Estonian Climate Ministry has detected a fuel leak on the wreck of the light cruiser HMS Cassandra, which sank west of the large Estonian island of Saaremaa after World War I, however, there is no significant pollution risk, as the fuel reaches the surface drop by drop and disperses quite quickly.

"The leak is small and slow, so the fuel reaching the surface breaks down and disperses due to waves and sunlight. There are only faint traces of dispersed oil visible on the surface," Kaspar Anderson, adviser at the Climate Ministry's marine environment department, said.  "This is not the kind of leak typically detectable through by satellite or aerial surveillance," he added.

Based on available data, Anderson noted that HMS Cassandra could accommodate up to a thousand tons of fuel oil. 

"The ship presumably had around 780 tons of fuel on board, a portion of which likely seeped into the sea at the time of sinking. Considering the wreck's relative integrity and state, it's presumed most of the fuel remains trapped within," the Climate Ministry's adviser said.

To date, 54 environmentally hazardous shipwrecks have been identified in Estonian waters. The environmental impact of 13 of these has been studied in more detail, and plans are in motion to investigate some of the others. The containment of such dangerous wrecks, including pumping them empty, is considered a high-risk and costly process, only undertaken when the situation may potentially become hazardous to people or the environment.

Officials continue to monitor the HMS Cassandra wreck closely, tracking any fluctuations in the leakage rate over time. Moreover, the Ministry of Climate is working on initiating an inter-agency cooperation project to prepare for the safe extraction of the remaining fuel from the wreck.