Secret Cities of the Seabed: How Do They Survive in the Inaccessible Depths of the Ocean?

Underwater Cities: Hydrothermal Vents

The secret to these "cities" is hidden in hydrothermal vents. These are fissures on the seabed from which geologically heated water emerges. The water can reach temperatures of up to 400°C and is rich in various chemical compounds like sulfur, iron, and methane. Around these fissures, unique ecosystems form where life exists without sunlight.

Here, a process called chemosynthesis takes place. While plants on Earth get energy from sunlight (photosynthesis), certain bacteria in these ecosystems get energy from the chemical compounds released from the thermal vents. These bacteria are the base of the food chain that allows other creatures to survive.

The Astonishing Inhabitants

The inhabitants of these "secret cities" are different from anything we know:

• Giant tube worms: They can grow up to 2 meters long and live in symbiosis with another organism. The bacteria living in their bodies create food through chemosynthesis.
• Scaly-foot gastropods: These snails have armored feet covered in iron sulfide, which protects them from predators.
• Abyssal crabs: They have adapted to the extremely cold water and high pressure.

Recent Research and Discoveries

Recent research conducted with submersibles has led to new discoveries. For example, in 2023, a new ecosystem was discovered near the Krichthon Seamount, where creatures have adapted to low-temperature currents emerging from the seabed. This breaks the stereotype that life in the deep is only possible under high-temperature conditions.

Furthermore, scientists are also studying the connection of these ecosystems to our planet's interior. The gases and liquids released from these vents can provide information about the geological processes occurring deep within the Earth, and the organisms living there can help us understand how life formed on our planet under extreme conditions.

Future Explorations

Studying these creatures and their survival strategies provides new answers to questions about the origin of life, both on our planet and on other celestial bodies such as Jupiter's moon Europa or Saturn's moon Enceladus, which are thought to have oceans beneath their icy surfaces. We still know very little about the depths of the ocean, and it remains one of humanity's greatest undiscovered frontiers.

Every new expedition into the deep has the potential to reveal species that are yet unknown to science.