What is going on here?
Our oceans are scattered with shipwrecks, each with a story of their own. Some of these still contain fuel onboard, which risks being released into the marine environment if the wrecks degrade or collapse. Ocean warming, ocean acidification and severe weather events all speed up the natural decomposition of shipwrecks, increasing the likelihood of this event.
What does this mean?
The majority of shipwrecks date back to the First and Second World Wars, and many of these contain heavy fuel oil, unexploded ammunition and other chemical pollutants – all of which would have severe environmental consequences in the case of a spill or explosion. As of 2023, the IUCN estimated there to be 8,500 potentially polluting wrecks lying underwater across the world.
As our seas are heavily impacted due to the climate crisis, conditions are being created thatcause the shipwrecks’ structure to degrade faster, increasing the risk of spills. There are a few reasons for this…
Ocean acidification can slowly corrode metal structures in ships. Severe weather events, which are increasing in both severity and frequency due to climate change, can physically break the wrecks down. Ocean warming is also increasing the expansion of invasive marine species. This may introduce new boring marine animals which are invertebrates known for burrowing holes through wood structures, speeding up their decomposition.
Bangor University is managing a marine survey to collect data on UK shipwrecks – two thirds of which lack any data on their polluting potential. Once understood that a wreck can be a risk, they can be protected by being buried in sand.
Why should we care?
Oil spills are a huge and significant threat to marine biodiversity. The cost of pollution spills is not only environmental but also financial, estimating at between $2,300 and $17,000 per tonne of oil spilled. Many wrecks lie submerged in global South waters, often in countries who didn’t even participate in the world wars, yet any resulting wreck pollution remains their responsibility to clean up- and finance.
Shipwrecks also boost local biodiversity. Over time, non-sessile marine organisms settle on the wrecks creating reefs. The underwater archaeology also deter destructive fishing methods such as bottom-trawling, accidentally protecting areas within up to a 50 metre radius around the wreck in the UK. They also attract tourists and can be of importance to heritage– wreck diving is even its own PADI qualification! The implications of fuel spills therefore extend to all of the above.
Be Curious!
- In the Great Lakes, decreased ice coverage is causing water levels to drop, exposing shallow shipwrecks.
- From the Curious Archives: read about how disastrous oil spills can be.
- Learn more about nearby shipwrecks using this interactive map!
Featured Image credit: Nott Peera via Unsplash
