Scientists working aboard the Falkor (too), a research vessel belonging to the Schmidt Ocean Institute, were amazed during their exploration. Left to collect samples in the East Pacific Ridge, their expedition ended up being more interesting than expected.
They discovered giant tube worms there (Riftia pachyptila) thriving in a fairly extreme environmentsince this area is very active from a volcanic point of view. The results of their observations were compiled in the review Nature Communications.
Perfectly Adapted Giants
This is thanks to the Subastian submersible vehicle (a remote-controlled submarine), sent to a depth of 2,500 metersthat they found these worms, populating natural cavities ten centimeters below the oceanic crust.
However, these marine organisms, which can reach the astonishing size of three meters, are not simple worms. Their bodies are home to an atrophied digestive system, replaced by a specialized organ called a trophosome. This unique adaptation allows them to host billions of symbiotic bacteria which constitute their only source of nutrition.
In these cavities where the temperature reaches 25°C, the bacteria carry out a process called chemosynthesis. They use the hydrogen sulphide present in hydrothermal fluids (hot, mineralized waters which circulate in the earth’s crust), transforming it into organic compounds essential for the survival of worms. This sophisticated symbiotic relationship allows Riftia to live without any dependence by sunlight or photosynthesis.
Secret life underground: In caves & cavities underneath the deep seafloor, large numbers of animals have their home. A discovery aided by data scientist André Luiz de Oliveira @maxplanckpress
Read @NatureComms@SchmidtOcean @univienna @NIOZatSea pic.twitter.com/MindClzOH7— Max Planck Institute for Marine Microbiology (@MarineMicrobio) October 15, 2024
A new understanding of deep-sea ecosystems
Scientists have discovered that these communities are part of a complex ecological network connecting three levels : the open ocean, the sea floor and the oceanic subsoil. The microscopic larvae of these worms, transported by hydrothermal currents, gradually colonize these underground habitats, thus creating a “biomass layer“.
We already knew about this layer, but scientists never thought that it could host such complex ecosystems. This means that it still remains to be fully studied. This could potentially shelter thousands of still unknown species and play an important role in protecting the seabed.
Unfortunately, this discovery is overshadowed by an imminent threat: deep water mining projects. These industrial activities, aimed at extracting precious minerals from the seabed, risk seriously disrupting, or even destroying, this ecosystem. Dredging, sediment discharges and noise pollution associated with these operations could have disastrous consequences on this environment. It is therefore urgent to realize the importance of protecting it so that it does not suffer the same fate as the Great Barrier Reef.
- Scientists have discovered giant worms in the Pacific Ocean.
- These live in underwater cavities and are part of a layer of complex organisms living under the earth’s crust.
- This layer is unfortunately already threatened by mining operations.
