Greenpeace Australia Pacific has released never-before-seen footage of a discarded oil tower owned by fossil fuel company Woodside, which has been allowed to sink to the ocean floor off the coast of Onslow, Western Australia, posing a hazard.

Greenpeace’s startling footage, captured by an underwater drone, reveals that the tower, which is approximately 100 metres tall, is visibly deteriorating. It sank upright, with the top of the structure 47 metres below sea level. The tower is in an area full of marine wildlife including whales and several dolphin species, and close to protected reefs.

The Griffin Field Riser Turret Mooring (RTM) sank in 2013 and Woodside (and previous owner BHP) have yet to remove it.