The Japan Times - 'Dark oxygen': a deep-sea discovery that has split scientists

EUR -
AED 4.009997
AFN 76.964387
ALL 99.220998
AMD 428.372779
ANG 1.968379
AOA 999.034005
ARS 1165.584001
AUD 1.711055
AWG 1.968042
AZN 1.857199
BAM 1.959344
BBD 2.205209
BDT 132.698836
BGN 1.955382
BHD 0.411398
BIF 3183.259907
BMD 1.09184
BND 1.454331
BOB 7.546652
BRL 6.209405
BSD 1.092186
BTN 94.829981
BWP 14.849931
BYN 3.574282
BYR 21400.066602
BZD 2.193879
CAD 1.560944
CDF 3139.040114
CHF 0.9622
CLF 0.02619
CLP 1005.044161
CNY 7.897495
CNH 7.892328
COP 4447.337821
CRC 544.780515
CUC 1.09184
CUP 28.933764
CVE 110.711967
CZK 25.046707
DJF 194.041291
DKK 7.460336
DOP 68.69472
DZD 145.329376
EGP 55.147741
ERN 16.377602
ETB 140.847322
FJD 2.518767
FKP 0.843782
GBP 0.840788
GEL 3.040797
GGP 0.843782
GHS 16.925835
GIP 0.843782
GMD 78.612163
GNF 9449.876318
GTQ 8.421311
GYD 228.50441
HKD 8.483216
HNL 28.125499
HRK 7.53413
HTG 143.240433
HUF 397.96491
IDR 17891.711296
ILS 3.987351
IMP 0.843782
INR 94.900397
IQD 1430.310574
IRR 45980.121683
ISK 146.098879
JEP 0.843782
JMD 171.049427
JOD 0.774225
JPY 163.173323
KES 141.396287
KGS 95.422243
KHR 4381.020106
KMF 492.256278
KPW 982.656119
KRW 1575.087516
KWD 0.336254
KYD 0.910151
KZT 544.560119
LAK 23649.257315
LBP 97828.875995
LKR 323.698534
LRD 217.367456
LSL 19.893461
LTL 3.22392
LVL 0.660443
LYD 5.259942
MAD 10.533526
MDL 19.632605
MGA 5104.352752
MKD 61.534726
MMK 2292.846866
MNT 3791.395104
MOP 8.741273
MRU 43.560216
MUR 49.187302
MVR 16.819017
MWK 1896.526117
MXN 21.787332
MYR 4.851592
MZN 69.779736
NAD 19.892911
NGN 1681.335433
NIO 40.13059
NOK 11.513356
NPR 151.72817
NZD 1.875124
OMR 0.420328
PAB 1.092176
PEN 3.9972
PGK 4.394113
PHP 62.567941
PKR 305.906312
PLN 4.186971
PYG 8679.701532
QAR 3.975419
RON 4.97737
RSD 117.16861
RUB 91.114111
RWF 1534.035387
SAR 4.09505
SBD 9.183779
SCR 15.66793
SDG 656.196144
SEK 11.018469
SGD 1.452251
SHP 0.858015
SLE 24.921287
SLL 22895.342846
SOS 623.992949
SRD 39.405596
STD 22598.886332
SVC 9.556287
SYP 14196.040638
SZL 19.893297
THB 36.674725
TJS 11.937266
TMT 3.82144
TND 3.35817
TOP 2.557202
TRY 40.015662
TTD 7.413343
TWD 35.997922
TZS 2891.06934
UAH 45.278709
UGX 4006.247279
USD 1.09184
UYU 46.544198
UZS 14139.329861
VES 71.564437
VND 27874.67859
VUV 134.249859
WST 3.077347
XAF 657.145773
XAG 0.032291
XAU 0.000364
XCD 2.950752
XDR 0.818277
XOF 657.834557
XPF 119.331742
YER 268.86575
ZAR 19.760603
ZMK 9827.870159
ZMW 31.327672
ZWL 351.572077
  • RBGPF

    -0.4100

    66.02

    -0.62%

  • SCS

    0.0200

    11.01

    +0.18%

  • NGG

    0.9300

    64.14

    +1.45%

  • BTI

    0.4800

    41.84

    +1.15%

  • GSK

    0.7600

    40.25

    +1.89%

  • RELX

    0.6700

    49.6

    +1.35%

  • RYCEF

    0.1000

    10.45

    +0.96%

  • CMSC

    0.1100

    23.33

    +0.47%

  • RIO

    0.4300

    63.47

    +0.68%

  • AZN

    -0.2300

    77.37

    -0.3%

  • BCC

    0.6500

    100

    +0.65%

  • JRI

    0.1700

    13

    +1.31%

  • BCE

    0.2300

    23.7

    +0.97%

  • BP

    0.3700

    33.76

    +1.1%

  • VOD

    0.3100

    9.86

    +3.14%

  • CMSD

    0.1900

    23.54

    +0.81%

'Dark oxygen': a deep-sea discovery that has split scientists
'Dark oxygen': a deep-sea discovery that has split scientists / Photo: Handout - National Oceanography Centre / Smartex project (NERC)/AFP/File

'Dark oxygen': a deep-sea discovery that has split scientists

Could lumpy metallic rocks in the deepest, darkest reaches of the ocean be making oxygen in the absence of sunlight?

Text size:

Some scientists think so, but others have challenged the claim that so-called "dark oxygen" is being produced in the lightless abyss of the seabed.

The discovery -- detailed last July in the journal Nature Geoscience -- called into question long-held assumptions about the origins of life on Earth, and sparked intense scientific debate.

The findings were also consequential for mining companies eager to extract the precious metals contained within these polymetallic nodules.

Researchers said that potato-sized nodules could be producing enough electrical current to split seawater into hydrogen and oxygen, a process known as electrolysis.

This cast doubt on the long-established view that life was made possible when organisms started producing oxygen via photosynthesis, which requires sunlight, about 2.7 billion years ago.

"Deep-sea discovery calls into question the origins of life," the Scottish Association for Marine Science said in a press release to accompany the publication of the research.

- Delicate ecosystem -

Environmentalists said the presence of dark oxygen showed just how little is known about life at these extreme depths, and supported their case that deep-sea mining posed unacceptable ecological risks.

"Greenpeace has long campaigned to stop deep sea mining from beginning in the Pacific due to the damage it could do to delicate, deep sea ecosystems," the environmental organisation said.

"This incredible discovery underlines the urgency of that call".

The discovery was made in the Clarion-Clipperton Zone, a vast underwater region of the Pacific Ocean between Mexico and Hawaii of growing interest to mining companies.

Scattered on the seafloor four kilometres (2.5 miles) beneath the surface, polymetallic nodules contain manganese, nickel and cobalt, metals used in electric car batteries and other low-carbon technologies.

The research that gave rise to the dark oxygen discovery was partly funded by a Canadian deep-sea mining business, The Metals Company, that wanted to assess the ecological impact of such exploration.

It has sharply criticised the study by marine ecologist Andrew Sweetman and his team as plagued by "methodological flaws".

Michael Clarke, environmental manager at The Metals Company, told AFP that the findings "are more logically attributable to poor scientific technique and shoddy science than a never before observed phenomenon."

- Scientific doubts -

Sweetman's findings proved explosive, with many in the scientific community expressing reservations or rejecting the conclusions.

Since July, five academic research papers refuting Sweetman's findings have been submitted for review and publication.

"He did not present clear proof for his observations and hypothesis," said Matthias Haeckel, a biogeochemist at the GEOMAR Helmholtz Centre for Ocean Research in Kiel, Germany.

"Many questions remain after the publication. So, now the scientific community needs to conduct similar experiments etc, and either prove or disprove it."

Olivier Rouxel, a geochemistry researcher at Ifremer, the French national institute for ocean science and technology, told AFP there was "absolutely no consensus on these results".

"Deep-sea sampling is always a challenge," he said, adding it was possible that the oxygen detected was "trapped air bubbles" in the measuring instruments.

He was also sceptical about deep-sea nodules, some tens of millions of years old, still producing enough electrical current when "batteries run out quickly".

"How is it possible to maintain the capacity to generate electrical current in a nodule that is itself extremely slow to form?" he asked.

When contacted by AFP, Sweetman indicated that he was preparing a formal response.

"These types of back and forth are very common with scientific articles and it moves the subject matter forward," he said.

M.Yamazaki--JT