Scientists have uncovered a remarkable deep-sea ecosystem off Papua New Guinea that could reshape understanding of life on the ocean floor. A new study, published in Scientific Reports, describes a previously unknown type of hydrothermal field where scorching underwater vents and methane-rich gas seeps occur side-by-side — a combination never documented before.
The discovery was made at a depth of around 1,300 meters near Conical Seamount in the western Pacific. During a 2023 research expedition aboard the German vessel SONNE, researchers deployed a remotely operated vehicle (ROV) to explore underwater volcanic formations — and were stunned by what they saw.
“We essentially have a hot vent bubbling right next to a cool gas seep — a combination that has never been described before,” said marine geologist Dr. Philipp Brandl of the GEOMAR Helmholtz Centre for Ocean Research Kiel, who led the expedition. He added that no previous missions in the area had spotted anything similar, making the find a major surprise, ScienceDaily reported.
The unusual system is driven by buried layers of organic-rich sediment beneath the seafloor. Rising magma heats these layers, releasing methane and other hydrocarbons, while also pushing hot, mineral-rich fluids upward. Because both forces use the same pathways to reach the surface, jets of scalding water and streams of cold gas escape just centimeters apart.
This rare geologic process has created a thriving habitat unlike any known in the deep ocean. Scientists observed dense clusters of mussels, tube worms, shrimp and even bright purple sea cucumbers carpeting the volcanic rock. Many species found here may be entirely new to science.
The site has been named “Karambusel” — meaning “mussel” in the local Tok Pisin language — in honor of the creatures that dominate the area. Dr. Brandl noted that some rocks were so crowded with marine life, “you couldn’t see a single patch of rock.”
Beyond its biological wonders, the site also features signs of past high-temperature activity — including traces of gold, silver and other minerals embedded in surrounding rock. These valuable deposits form when metal-rich hydrothermal fluids cool and solidify, suggesting that the region may once have been even more volcanically active than it is today.
However, this newfound ecosystem could already be in danger. Mining activity nearby — including the large Ladolam gold mine on Lihir — has raised concerns about pollution and habitat disruption. Additional licenses for deep-sea mineral and hydrocarbon exploration are active in the region as well.
Calling the discovery a “treasure trove of biodiversity,” the research team urged policymakers to protect the Karambusel field before industrial development causes irreversible harm. “We have discovered an unexpected treasure trove of biodiversity in the Karambusel field that needs to be protected before economic interests destroy it,” said Dr. Brandl.
With many species yet to be identified and a unique environment unlike any found elsewhere on Earth, scientists say further research is urgently needed — along with strong marine conservation measures to preserve this hidden world in the deep.
