太平洋深处的“暗氧”( ‘Dark oxygen’ )可能迫使人们重新思考生命的起源

太平洋克拉里昂克利珀顿区(the Clarion Clipperton Zone of the Pacific Ocean)海底的岩石，称为多金属结核。这些块的电荷类似于 AA 电池。照片：GSR/路透社

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.

在太平洋深处完全黑暗的地方，科学家们发现氧气不是由生物体产生的，而是由奇怪的土豆形状的金属块产生的，这些金属块发出的电力几乎与 AA 电池一样多。

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

一项研究背后的研究人员周一表示，这一令人惊讶的发现具有许多潜在的影响，甚至可能需要重新思考地球上生命最初是如何开始的。

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

人们一直认为，只有植物和藻类等生物才能通过光合作用产生氧气——这需要阳光。

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

但在太平洋表面以下 4 公里（2.5 英里）处，阳光无法到达的地方，被称为多金属结核的小型矿床首次被记录为制造所谓的暗氧。

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.

这一发现是在克拉里昂-克利珀顿区（CCZ）发现的，这是一个延伸在夏威夷和墨西哥之间的深海平原，矿业公司计划在那里开始收获结核。

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.

这些块状结核通常被称为“岩石中的电池”，富含钴、镍、铜和锰等金属，这些金属均用于电池、智能手机、风力涡轮机和太阳能电池板。

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

国际科学家团队派出了一艘小船到 CCZ 的地面，旨在了解采矿对生活在光线无法到达的地方的奇怪且鲜为人知的动物有何影响。

“We were trying to measure the rate of oxygen consumption by the seafloor,” lead study author Andrew Sweetman of the Scottish Association for Marine Science (SAMS) told AFP.

苏格兰海洋科学协会（SAMS）的主要研究作者安德鲁·斯威特曼（Andrew Sweetman）告诉法新社：“我们试图测量海底的氧气消耗率。”

To do so, they used a contraption called a benthic chamber, which snatched up a bunch of sediment.

为此，他们使用了一种称为底栖室的装置，它可以捕获一堆沉积物。

Normally, the amount of oxygen trapped in the chamber “decreases as its used up by organisms as they respire”, Sweetman said.

斯威特曼说，通常情况下，室内的氧气量“随着生物体呼吸时的消耗而减少”。

But this time the opposite happened – the amount of oxygen increased. This was not supposed to happen in complete darkness where there is no photosynthesis.

但这一次发生了相反的情况——氧气量增加了。这不应该发生在没有光合作用的完全黑暗中。

This was so shocking that the researchers initially thought their underwater sensors must have been on the blink. So they brought up some nodules to their ship to repeat the test. Once again, the amount of oxygen increased.

这太令人震惊了，研究人员最初认为他们的水下传感器一定是在眨眼。因此他们将一些结核带上船来重复测试。氧气含量再次增加。

They then noticed how the nodules were carrying a startling electric charge.

然后他们注意到这些结核如何携带惊人的电荷。

On the surface of the nodules, the team “amazingly found voltages almost as high as are in an AA battery”, Sweetman said. This charge could split seawater into hydrogen and oxygen in a process called seawater electrolysis, the researchers said.

斯威特曼说，在结节表面，研究小组“令人惊讶地发现电压几乎与 AA 电池一样高”。研究人员表示，这种电荷可以在海水电解过程中将海水分解成氢气和氧气。

This chemical reaction occurs at about 1.5 volts – approximately the charge of an AA battery.

这种化学反应在大约 1.5 伏电压下发生——大约相当于 AA 电池的电量。

Nicholas Owens, the SAMS director, said it was “one of the most exciting findings in ocean science in recent times”.

SAMS 主任尼古拉斯·欧文斯 (Nicholas Owens) 表示，这是“近年来海洋科学领域最令人兴奋的发现之一”。

The discovery of oxygen produced outside of photosynthesis “requires us to rethink how the evolution of complex life on the planet might have originated”, he said.

他说，光合作用之外产生的氧气的发现“要求我们重新思考地球上复杂生命的进化可能是如何起源的”。

“The conventional view is that oxygen was first produced around 3bn years ago by ancient microbes called cyanobacteria and there was a gradual development of complex life thereafter,” Owens said.

欧文斯说：“传统观点认为，大约 30 亿年前，称为蓝细菌的古老微生物首先产生了氧气，此后复杂生命逐渐发展起来。”

Sweetman said the team’s discovery showed that “life could have started elsewhere than on land”.

斯威特曼表示，该团队的发现表明“生命可能起源于陆地以外的其他地方”。

“And, if the process is happening on our planet, could it be helping to generate oxygenated habitats on other ocean worlds such as Enceladus and Europa and providing the opportunity for life to exist?” he said.

“而且，如果这个过程发生在我们的星球上，它是否有助于在土卫二和木卫二等其他海洋世界上产生含氧栖息地，并为生命的存在提供机会？”他说。

The study, published in the journal Nature Geoscience, was partly funded by Canada’s The Metals Company, which is aiming to start mining the nodules in the CCZ next year.

这项研究发表在《自然地球科学》杂志上，部分由加拿大金属公司资助，该公司计划明年开始开采 CCZ 的结核。