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Biodiversity loss from deep-sea mining

June 2017
Nature Geoscience 10(7):464–465

DOI:10.1038/ngeo2983

Project: Common Heritage of Humankind and the Deep Sea

Authors:

Cindy Lee Van Dover

Duke University

Jeff A. Ardron

Commonwealth Secretariat, London, UK

Elva Escobar

Universidad Nacional Autónoma de México

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NATURE GEOSCIENCE | ADVANCE ONLINE PUBLICATION | www.nature.com/naturegeoscience 1

correspondence

To the Editor — e emerging deep-sea

mining industry is seen by some to be

an engine for economic development in

the maritime sector1. e International

Seabed Authority — the body that

regulates mining activities on the seabed

beyond national jurisdiction — must also

protect the marine environment from

harmful eects that arise from mining2.

e International Seabed Authority is

currently draing a regulatory framework

for deep-sea mining that includes

measures for environmental protection.

Responsible mining increasingly strives

to work with no net loss of biodiversity3.

Financial and regulatory frameworks

commonly require extractive industries

to use a four-tier mitigation hierarchy

to prevent biodiversity loss: in order of

priority, biodiversity loss is to be avoided,

minimized, remediated and — as a last

resort — oset4,5. We argue here that

mining with no net loss of biodiversity

using this mitigation hierarchy in the deep

sea is an unattainable goal.

e rst tier of the mitigation hierarchy

is avoidance. Potentially useful mitigation

strategies in the deep sea include patchwork

extraction, whereby some minerals with

associated fauna are le undisturbed, or

other means to limit the direct mining

footprint. Even so, loss of biodiversity will

be unavoidable because mining directly

destroys habitat and indirectly degrades

large volumes of the water column and

areas of the seabed due to the generation

of sediment plumes that are enriched in

bioavailable metals.

Although biodiversity loss within

mines is inevitable, innovative engineering

design could reduce or minimize some

risks to near- and far-eld biodiversity.

For example, shrouds tted to cutting

equipment might reduce the dispersion

of sediment plumes and the footprint

of plume impacts such as the burial of

organisms. Similarly, vehicle design might

limit compaction of seabed sediments.

Of course, the ecacy of such eorts in

mitigating biodiversity loss would need to

be tested.

Remediation addresses the residual

loss of biodiversity at and around a mine

site aer avoidance and minimization

interventions. In the deep sea, native

species are oen slow to recruit and

recolonize disturbed habitats. Slow

recovery on the scale of decades to

centuries, enormous spatial scales of mines

for certain mineral resources (a single

30-year operation license to mine metal-

rich nodules will involve an area about

the size of Austria6) and the high cost of

working in the deep sea may mean that

remediation is unrealistic7. Further, the

science of deep-sea benthic remediation is

a nascent eld8. It is far from established

that remediation of industrial mine sites

in the deep sea is feasible for any mineral

resource, and we know of no remediation

actions that can be applied to the

water column.

e last resort in the mitigation

hierarchy is in-kind or like-for-like

osets within a biogeographical region.

When osets cannot be located where the

aected biodiversity is found, and where

the aected biodiversity is important for

geographically restricted functions such

as connectivity (as is the case for the deep

sea), in-kind osets are not an appropriate

mitigation strategy9. Out-of-kind osets10,

such as restoring coral reefs in exchange

for loss of deep-sea biodiversity, have been

proposed, but this practice assumes that

loss of largely unknown deep-sea species

and ecosystems is acceptable. We question

this assumption on scientic grounds. e

relationship between any gain in biological

diversity in an out-of-kind setting and

loss of biological diversity in the deep

sea is so ambiguous as to be scientically

meaningless. Further, compensating

biodiversity loss in international waters

with biodiversity gains in national waters

could constitute a transfer of wealth that

runs counter to the Law of the Sea, where

benets from deep seabed mining must

accrue to the international community at

large, as part of the common heritage of

humankind. Given the paucity of other

industrial activities in the deep sea (except

perhaps sheries), it is dicult to imagine

a scenario where averted risk osets10 could

apply; that is, where a mining operation

could avert biodiversity losses from

other activities.

e four-tier mitigation hierarchy used

so oen to minimize biodiversity loss in

terrestrial mining and oshore oil and

gas operations thus fails when applied

to the deep ocean. Residual biodiversity

loss cannot be mitigated through

remediation or osets and the goal of no

net loss of biodiversity is not achievable for

deep-seabed mining. Focus therefore must

be on avoiding and minimizing harm. Most

mining-induced loss of biodiversity in the

deep sea is likely to last forever on human

timescales, given the very slow natural

rates of recovery in aected ecosystems. It

is incumbent on the International Seabed

Authority to communicate to the public the

potentially serious implications of this loss

of biodiversity and ask for a response. ❐

References

1. Blue Growth: Opportunities for Marine and Maritime

Sustainable Growth (European Comission, 2012);

http://dx.doi.org/10.2771/43949

2. Levin, L.A. etal. Mar. Poli cy 74, 245–259 (2016).

3. Rainey, H.J. etal. Oryx 49, 232–238 (2015).

4. Ekstrom, J., Bennun, L. & Mitchell, R. A Cross-sector Guide for

Implementing the Mitigation Hierarchy (Cross Sector Biodiversity

Initiative, 2015).

5. Performance Standard 6: Biodiversity Conservation and

Sustainable Management of Living Natural Res ources

(International Finance Corporation, 2012).

6. Smith, C.R., Levin, L.A., Koslow, A., Tyler, P.A. &

Glover, A.G. in Aquatic Ecosystems: Trends and Global Prospects

(ed. Polunin, N.) 334–349 (Cambridge Univ. Press, 2008).

7. Van Dover, C.L. etal. Mar. P olic y 44, 98–106 (2014).

8. Strömberg, S.M., Lundälv, T. & Goreau, T.J. J.Exp. Mar. Bio. Ecol.

395, 153–161 (2010).

9. Pilgrim, J.D. etal. Conserv. Lett. 6, 376–384 (2013).

10. Guidance Notes to the Standard on Biodiversity Osets (Business

and Biodiversity Osets Program, 2012).

Biodiversity loss from deep-sea mining

The Tu’i Malila vent ﬁeld in the Lau Basin,

southwest Paciﬁc. Lau Basin foundation species

(Alviniconcha spp. snails, Ifremeria nautilei snails,

and Bathymodiolus septemdierum mussels) live

in diuse ﬂow on the surfaces of metal-rich

sulﬁde deposits.

KAREN JACOBSEN, IN SITU SCIENCE ILLUSTRATION

2 NATURE GEOSCIENCE | ADVANCE ONLINE PUBLICATION | www.nature.com/naturegeoscience

correspondence

C. L. Van Dover1*, J. A. Ardron2, E. Escobar3,

M. Gianni4, K. M. Gjerde5, A. Jaeckel6,

D. O. B. Jones2, L. A. Levin7, H. J. Niner8,

L. Pendleton1,9, C. R. Smith10, T. Thiele11,

P. J. Turner1, L. Watling12 and P. P. E. Weaver13

1Division of Marine Science and Conservation,

Nicholas School of the Environment, Duke

University, Beaufort, North Carolina 28516, USA.

2National Oceanography Centre, University of

Southampton, Waterfront Campus, European

Way, Southampton SO14 3ZH, UK. 3UNAM

ICML-CU, Biodiversidad y Macroecologia, 04510

Mexico City, Mexico. 4Deep-Sea Conservation

Coalition, Postbus 59681, 1040 LD Amsterdam,

Netherlands. 5IUCN Marine and Polar Programme,

Cambridge, Massachusetts 02138, USA.

6Macquarie Law School and Macquarie Marine

Research Centre, Macquarie University, New

South Wales 2109, Australia. 7Center for Marine

Biodiversity and Conservation, Scripps Institution

of Oceanography, UC San Diego, La Jolla,

California 92093-0218 USA. 8University College

London, Torrens Building, 220 Victoria Square,

Adelaide 5000, Australia. 9Université de Bretagne

Occidentale, UMR6308 AMURE, IUEM, 29280

Plouzané, France. 10Department of Oceanography,

1000 Pope Road, University of Hawaii at Mānoa,

Honolulu, Hawaii 96822 USA. 11Institute of

Global Aairs, London School of Economics,

London WC2A 2AZ, UK. 12Department of Biology,

Edmondson Hall, University of Hawaii at Mānoa,

Honolulu, Hawaii 96822, USA. 13Seascape

Consultants, Romsey SO51 0QA, UK.

*e-mail: clv3@duke.edu

Acknowledgements

Research leading to these ndings was supported by the

National Science Foundation (C.L.V.D.), Pew Charitable

Trusts (C.L.V.D.), International Climate Initiative (GOBI;

C.L.V.D.), Université Occidental de Bretagne and Institut

Universitaire Européen de la Mer (C.L.V.D., L.P.), 7th

EU Framework (MIDAS #603418; J.A.A., D.O.B.J., M.G.,

K.M.G., P.P.E.W.), EU Horizon 2020 (MERCES #689518,

D.O.B.J.) and the J.M. Kaplan Fund (L.A.L.).

Competing interests

C.L.V.D. and L.A.L. received research support from

Nautilus Minerals; C.R.S. received research support from

UK Seabed Resources DevelopmentLimited.

Published online: 26 June 2017

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