Creatures found living off gas in Pacific Ocean's deepest trenches

Telegraph

6 days ago

A strange menagerie of creatures living off methane have been found in the darkest depths of the Pacific Ocean.
Spiky white worms and tiny marine snails were filmed picking their way through swaying fields of tube-worms, more than five miles from the surface.
Chinese explorers who visited the area by submarine also found huge beds of clams and large patches of white, snow-like microbial mats.
The waving carpets of worms looked so much like countryside meadows that scientists labelled them 'Cotton Field' and 'Wintersweet Valley', while the blanched microbial mats were dubbed 'Icy River'.
The creatures are all the more remarkable because they live in complete darkness along major fault-lines where two tectonic plates meet, surviving on hydrogen sulfide and methane produced by seismic activity.
The Kuril–Kamchatka Trench, formed by the Pacific Plate moving beneath the Okhotsk Plate, was the site of this week's earthquake which sent tsunami waves crashing onto the shores of the US and Japan.
It is not known how the newly-discovered creatures have been impacted by the earthquake.
The new expedition covered more than 1,500 miles, exploring the trench at depths ranging from 3.6 miles to 5.9 miles beneath the surface.
It was led by the Chinese Academy of Sciences' Institute of Deep Sea Science and Engineering who said finding a 'flourishing' community in such a hostile environment made it likely similar ecosystems were thriving in other harsh environments.
The team says it now wants to find out how life manages to survive in the high pressure environments of hadal trenches – the very deep fissures at the bottom of oceans. It has collected a number of samples to study in the lab.
Co-lead author on the study, Xiatong Peng, from China's Institute of Deep-sea Science and Engineering at the Chinese Academy of Science, said: 'Hadal trenches, some of the Earth's least explored and understood environments have long been proposed to harbour chemosynthesis-based communities.
'Yet, despite increasing attention, actual documentation of such communities has been exceptionally rare.'
'Here we report the discovery of the deepest and the most extensive chemosynthesis-based communities known to exist on Earth.
'Given geological similarities with other hadal trenches, such chemosynthesis-based communities might be more widespread than previously anticipated.'
Creatures that exist in such inhospitable locations are known as 'extremophiles' and they were first discovered living in hydrothermal vents in the 1980s.
Trawls from the region had pulled up chemical-eating worms, but it is the first time that such a diverse and thriving living community has been found living at such depths.
The communities are dominated by marine tube-worms called siboglinid polychaetes and molluscs called bivalves, which synthesise their energy using hydrogen sulfide and methane seeping out of faults in the tectonic plate.
Further analysis suggests that the methane seeping out of the cracks is made by microbial processes in organic matter found in sediments.
The images were taken by the manned submersible equipped with a high-definition camera system.
The research was published in the journal Nature.