Chapter 13
ANTHROPOGENIC IMPACTS ON THE DEEP SEA
Hjalmar THIEL
DEEP-SEA IMPACTS
The deep sea has received broad attention in the
preceding chapters of this volume, a recognition that
it is the largest, continuous ecological unit on earth.
However, it is also of all environments the most remote
and least well known, both to scientists and to the
public. But this remoteness has not protected the
deep sea from anthropogenic impacts. Wastes released
anywhere on the high seas or into the atmosphere may
rapidly sink into the abyss, to be out of sight and out
of mind. Invisible and visible wastes penetrate this vast
volume of water from a variety of sources and via
different pathways. There are few areas of the world’s
oceans that have not received any anthropogenic
impact, invisibly and by slow-paced transport. Life is
ubiquitous in the oceans. Since most species require
oxygen, this essential gas must be transported to all
locales with the currents; and these same currents
transport invisible contaminants.
These invisible substances have travelled for long
distances and periods of time, and may affect organisms
many degrees of latitude and longitude away from
their origin and their entrance to the oceans. In
contrast, human intrusions into the deep sea are already
direct sources of environmental disturbances, and these
intrusions, visible and made with consciousness of their
impact, may become more numerous and more serious
in coming years.
Anthropogenic impacts in the deep sea deserve
serious consideration and international legal regulation.
Invisible deep-sea contaminants may eventually return
to the ocean surface, add to the local pollution, and
disturb species or communities and eventually man
through direct or synergistic effects. Turn-over times
in the oceans, depending on regional peculiarities, are
estimated at a few hundreds to one thousand years
or so. One has no idea what the pollution status of
the ocean surface will be when contaminants resurface
after such long time periods.
Visible contaminants, intentionally dumped into the
deep sea, cannot be retrieved. Any realization that
specific substances may not have found their final
storage at great ocean depth will inevitably come
too late; there would be no possibility to redress the
situation. Similarly, impacts occurring in the deep sea
as a consequence of mining mineral resources will have
long-term effects.
A thorough knowledge of the ecology of the deep sea
is essential to arrive at the right decisions. However,
effective protective measures for the deep sea will
be possible only if the impacts are known or their
extent can be estimated. These are certainly difficult
tasks, but impact prediction must be undertaken a
long time in advance. Oceanographers of all disciplines
must think ahead. Appropriate deep-sea research must
be conducted, targeted so as to understand potential
impacts, and experimental large-scale approaches are
essential.
From a conservation point of view the deep sea
is firmly within the ambit of the human community despite its remoteness. Besides ocean scientists,
politicians, economists, and engineers must take the
potential disturbance of the far-distant deep sea into
account. They all share responsibility for the deep sea
as part of the oceans and the human environment.
NON-VISIBLE CONTAMINATION
Radiation
On 4th July, 1986 Erlenkeuser and Balzer (1988)
collected two box corer samples off mid Norway (at
427
ANTHROPOGENIC IMPACTS ON THE DEEP SEA
Hjalmar THIEL
DEEP-SEA IMPACTS
The deep sea has received broad attention in the
preceding chapters of this volume, a recognition that
it is the largest, continuous ecological unit on earth.
However, it is also of all environments the most remote
and least well known, both to scientists and to the
public. But this remoteness has not protected the
deep sea from anthropogenic impacts. Wastes released
anywhere on the high seas or into the atmosphere may
rapidly sink into the abyss, to be out of sight and out
of mind. Invisible and visible wastes penetrate this vast
volume of water from a variety of sources and via
different pathways. There are few areas of the world’s
oceans that have not received any anthropogenic
impact, invisibly and by slow-paced transport. Life is
ubiquitous in the oceans. Since most species require
oxygen, this essential gas must be transported to all
locales with the currents; and these same currents
transport invisible contaminants.
These invisible substances have travelled for long
distances and periods of time, and may affect organisms
many degrees of latitude and longitude away from
their origin and their entrance to the oceans. In
contrast, human intrusions into the deep sea are already
direct sources of environmental disturbances, and these
intrusions, visible and made with consciousness of their
impact, may become more numerous and more serious
in coming years.
Anthropogenic impacts in the deep sea deserve
serious consideration and international legal regulation.
Invisible deep-sea contaminants may eventually return
to the ocean surface, add to the local pollution, and
disturb species or communities and eventually man
through direct or synergistic effects. Turn-over times
in the oceans, depending on regional peculiarities, are
estimated at a few hundreds to one thousand years
or so. One has no idea what the pollution status of
the ocean surface will be when contaminants resurface
after such long time periods.
Visible contaminants, intentionally dumped into the
deep sea, cannot be retrieved. Any realization that
specific substances may not have found their final
storage at great ocean depth will inevitably come
too late; there would be no possibility to redress the
situation. Similarly, impacts occurring in the deep sea
as a consequence of mining mineral resources will have
long-term effects.
A thorough knowledge of the ecology of the deep sea
is essential to arrive at the right decisions. However,
effective protective measures for the deep sea will
be possible only if the impacts are known or their
extent can be estimated. These are certainly difficult
tasks, but impact prediction must be undertaken a
long time in advance. Oceanographers of all disciplines
must think ahead. Appropriate deep-sea research must
be conducted, targeted so as to understand potential
impacts, and experimental large-scale approaches are
essential.
From a conservation point of view the deep sea
is firmly within the ambit of the human community despite its remoteness. Besides ocean scientists,
politicians, economists, and engineers must take the
potential disturbance of the far-distant deep sea into
account. They all share responsibility for the deep sea
as part of the oceans and the human environment.
NON-VISIBLE CONTAMINATION
Radiation
On 4th July, 1986 Erlenkeuser and Balzer (1988)
collected two box corer samples off mid Norway (at
427