'Dark Oxygen' in Depths of Pacific Ocean Prompts New Theories on Life's Origins

Relicanthus sp, a new species from a new order of Cnidaria collected at 4,100 meters in the Clarion-Clipperton Fracture Zone (CCZ) that lives on sponge stalks attached to nodules - AFP
Relicanthus sp, a new species from a new order of Cnidaria collected at 4,100 meters in the Clarion-Clipperton Fracture Zone (CCZ) that lives on sponge stalks attached to nodules - AFP
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'Dark Oxygen' in Depths of Pacific Ocean Prompts New Theories on Life's Origins

Relicanthus sp, a new species from a new order of Cnidaria collected at 4,100 meters in the Clarion-Clipperton Fracture Zone (CCZ) that lives on sponge stalks attached to nodules - AFP
Relicanthus sp, a new species from a new order of Cnidaria collected at 4,100 meters in the Clarion-Clipperton Fracture Zone (CCZ) that lives on sponge stalks attached to nodules - AFP

Scientists have discovered that metallic nodules on the seafloor produce their own oxygen in the dark depths of the Pacific Ocean. These polymetallic nodules, generating electricity like AA batteries, challenge the belief that only photosynthetic organisms create oxygen, potentially altering our understanding of how life began on Earth, AFP reported.

In the total darkness of the depths of the Pacific Ocean, scientists have discovered oxygen being produced not by living organisms but by strange potato-shaped metallic lumps that give off almost as much electricity as AA batteries.

The surprise finding has many potential implications and could even require rethinking how life first began on Earth, the researchers behind a new study said on Monday.

It had been thought that only living things such as plants and algae were capable of producing oxygen via photosynthesis -- which requires sunlight.

But four kilometres (2.5 miles) below the surface of the Pacific Ocean, where no sunlight can reach, small mineral deposits called polymetallic nodules have been recorded making so-called dark oxygen for the first time.

The discovery was made in the Clarion-Clipperton Zone (CCZ), an abyssal plain stretching between Hawaii and Mexico, where mining companies have plans to start harvesting the nodules.

The lumpy nodules -- often called "batteries in a rock" -- are rich in metals such as cobalt, nickel, copper and manganese, which are all used in batteries, smartphones, wind turbines and solar panels.

The international team of scientists sent a small vessel to the floor of the CCZ aiming to find out how mining could impact the strange and little understood animals living where no light can reach.

nodules in the CCZ next year.



Tunisia's Sandy Beaches Eaten away by Coastal Erosion

A man looks on as a digger spreads sand on a beach in the tourist town of Hammamet as authorities fight to protect the coast from rising sea levels and erosion. FETHI BELAID / AFP
A man looks on as a digger spreads sand on a beach in the tourist town of Hammamet as authorities fight to protect the coast from rising sea levels and erosion. FETHI BELAID / AFP
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Tunisia's Sandy Beaches Eaten away by Coastal Erosion

A man looks on as a digger spreads sand on a beach in the tourist town of Hammamet as authorities fight to protect the coast from rising sea levels and erosion. FETHI BELAID / AFP
A man looks on as a digger spreads sand on a beach in the tourist town of Hammamet as authorities fight to protect the coast from rising sea levels and erosion. FETHI BELAID / AFP

In Tunisia's seaside town of Hammamet, bulldozers diligently shovel sand from a nearby desert onto a popular beach in an attempt to stop it from disappearing due to erosion.
"This beach is the postcard image of Hammamet," said environmentalist Chiheb Ben Fredj peering nostalgically at the town's iconic Yasmine beach.
"It has been seared in our minds since our childhood," he added, as laborers worked to restore the central Tunisian waterfront to its former sandy glory, reported Agence France Presse.
Like many other coastal areas in North Africa, severe erosion has led to many of Hammamet's sandy beaches vanishing in recent years, taking a toll on the holiday hotspot about 65 kilometers (40 miles) east of the capital Tunis.
Coastlines across the world are in a constant natural flux, with the seas claiming and depositing sediment.
But human activity, including coastal property development and offshore sand mining, significantly accelerates beach erosion.
Among other impacts, construction and coastal defenses in one area can stop sediment from traveling along a coastline, leaving existing beaches deprived of new material.
Studies have also shown the impacts of climate change, including rising temperatures and sea levels, exacerbate the phenomenon.
Tourism draw
In the Mediterranean, where the British National Oceanography Centre says sea levels have risen at a higher rate over the past 20 years than the entirety of the 20th century, shorelines are changing rapidly.
The sea is also warming 20 percent faster than the rest of the world, according to the United Nations.
Tunisia's coastline has been a major asset for the Mediterranean country with a struggling economy, as it aims to host some 10 million tourists this year.
Tourism accounts for up to 14 percent of the country's GDP, providing tens of thousands of jobs in a country where unemployment tops 16 percent and 40 percent among young people.
Tunisia has already lost more than 90 kilometers of beaches to erosion, according to official figures from last year.
Of the country's 570 kilometers of sandy beaches suitable for swimming, 190 kilometers are at imminent risk of disappearing, according to Tunisian reports.
A majority of the beaches most affected by erosion are located near cities.
Tunisia's environmental groups, as well as the government's Coastal Protection and Development Agency (APAL), blame the rapid erosion mostly on human activity and construction on the coast, which they say is further aggravated by climate change.
"Construction projects have not been designed to respect coastal dynamics," an APAL official told AFP.
'Not sustainable'
To save the Hammamet beach, one of Tunisia's worst-affected according to the World Bank, authorities last month began trucking in around 750 lorry loads filled with sand from the inland desert province of Kairouan, about 110 kilometers away.
APAL, which operates under the environment ministry, was in a race against time to refill the beach before the peak of tourist season.
But while the rebuilding of beaches, known as beach nourishment, may be a quick fix, "it's not a sustainable solution", said Ben Fredj.
"This sand may not last long," added the secretary general of the Environmental Education Association.
"It can be swallowed in a few days in the event of a storm", he said, as was the case in the summer of 2023.
The process can also prove expensive.
Coastal authorities estimated the cost of restoring sand to three beaches in Hammamet, Monastir and Sfax at 3.9 million Tunisian dinars ($1.25 million).
But for locals, restoring their priceless seafront is worth the money.
The Yasmine beach "is a showcase for Hammamet," said Narjess Bouasker, who runs the town's Menara hotel and leads the regional hotel federation.
"We must take back our beach that the sea has swallowed," she said, calling for a balance between safeguarding the landscape, cherished by locals and foreign visitors alike, and fighting coastal erosion.
"For us, the priority is not to touch the beauty of the city," she said.
Bouasker said she has seen increasing awareness among authorities, but refilling beaches with sand is still a gamble.
"We don't know how the sea will react", she added.