In the ocean deep exist environments so harsh that only the most hardcore of extremophiles can survive them. Super salty brine pools are deadly for larger animals, but some hardy microbe species can be found living it up within them, as well as pristinely preserved ocean sediments, new research has found.

These precious pools of undisturbed ocean detritus could prove to act as windows into the past, as the sediments in a newly-discovered complex of brine pools were found to date back thousands of years. Their discovery is detailed in a paper published in communications earth & environment, authored by the researchers who found and sampled the brine pools at a depth of 1,770 meters (5,800 feet) off the shores of Saudi Arabia.

The deep sea brine pools have been named NEOM by the study authors, who, having stumbled across fresh sampling grounds, helped themselves to a few scientific souvenirs.

“Given that these pools were found in a location that had never been reported before, a series of in situ measurements and samples (water, surficial sediment samples, and cores) were collected for the purposes of characterizing the overall physical setting of the pools, their sedimentology, chemistry, and biology,” wrote the authors.

With an armful of deep-sea samples, they could get to work establishing if the NEOM pools fall into the same category as other Red Sea brine pools, or if they present a shiny new category on their own. A crucial division between the two is that NEOM sits so close to the shore (within a couple of kilometers) while the next closest is a hefty 25 kilometers (15.5 miles) away from the nearest land.

Cozying up so close to Saudi Arabia means that NEOM could well contain the historical footprints of tsunamis, flash floods, and seismic activity in the Gulf of Aqaba. As for searching for clues, the researchers had one mega-pool as well as three mini pools to choose from, with the largest stretching across 10,000 meters² compared to the more modest pools of less than 10 meters².

A submersible remote-operated vehicle (ROV) got busy doing the grunt work for six weeks and found that, despite their extreme conditions, the NEOM brine pools are home to a rich diversity of microbial life. While surprising on the surface, life is thought to have originated from the deep, dark, and oxygen-sparse corners of our oceans, which makes these pools an opportune place for studying early life as well as past environmental conditions.

“Deep-sea brine pools are a great analog for the early Earth and, despite being devoid of oxygen and hypersaline, are teeming with a rich community of so-called 'extremophile' microbes,” said study lead author Sam Purkis, a professor and chair of the Department of Marine Geosciences at the University of Miami, to Live Science.

"Studying this community hence allows a glimpse into the sort of conditions where life first appeared on our planet, and might guide the search for life on other 'water worlds' in our Solar System and beyond."

There’s great academic depth, then, to these dingy pools, and with so few discoveries to date, the arrival of the NEOM pools is a welcome one indeed for marine geoscientists.

[H/T: Science Alert]