UK Defence Ministry launches mission to prevent oil leaks from WWI shipwreck off Estonia

The UK Ministry of Defence (MOD) has begun a study of a shipwreck on the seabed off the coast of Estonia as part of a broader project aimed at preventing the sunken vessel from leaking oil and other pollutants into the surrounding waters.

The wreck being studied is that of HMS Cassandra, a Royal Navy cruiser that was lost in the Baltic Sea off Estonia's Saaremaa Island after it struck a mine in the weeks following the end of World War I.

Most of Cassandra's 400 crew survived, but 11 went down with the cruiser, whose wreck lies in around 100 metres of water.

The Royal Navy hydrographic ship HMS Echo surveyed the site four years ago, but now a far more detailed study is being conducted by the MOD's Salvage and Maritime Operations (SALMO) team.

SALMO manages the MOD-owned inventory of potentially-polluting wrecks on behalf of Navy Command and the Waves Group.

Matt Skelhorn, Head of the UK MOD Wreck Management Programme at Defence Equipment and Support SALMO, said the findings would be shared widely, as the UK had worked with Estonian authorities to ensure the Baltic Sea was not subjected to oil leaking from the wreck.

"HMS Cassandra has the potential to become a blueprint for future international collaboration when it comes to addressing the risks caused by potentially-polluting wrecks," said Skelhorn.

The MOD said it is thought that there are around 8,500 wrecks from the 20th century's global conflicts lying at the bottom of the world's oceans.

London-based non-profit Project Tangaroa has called on governments to act to prevent pollutants from these wrecks from spreading out into the ocean.

The Tangaroa team said that after 80 to 110 years beneath the waves, all of the wrecks are becoming increasingly unstable, with some already leaking oil.