A research team from the Institute of Deep-sea Science and Engineering at the Chinese Academy of Sciences has discovered the deepest and most extensive chemosynthesis-based biological communities ever recorded, located more than 10 kilometers (6 miles) beneath the ocean surface. The exploration was conducted using the manned submersible Fendouzhe. These communities consist of tubeworms and mollusks that sustain themselves by consuming bacteria which metabolize methane in complete darkness. This finding challenges existing understandings of biological limits and reveals a previously unknown network of life thriving in one of Earth's most hostile environments. The discovery has been described as a significant advancement in understanding how life can exist in extreme conditions. Concurrently, scientists have warned that extreme marine heat recorded since 2023 may indicate an impending regime shift in the world's oceans, posing serious risks to global marine ecosystems.