Chapter 1
INTRODUCTION
Paul A. TYLER
The largest single ecosystem on earth is the deep
sea. The sea surface occupies ~70% of the surface
of the earth, and 50% of the surface of the earth
is covered by more than 3000 m of ocean, with a
mean depth of ~3800 m. It is the very remoteness
of the deep sea and the difficulties encountered in
its exploration that have resulted in it being one of
the least understood environments on earth. At the
present time there is detailed information about specific
areas of the deep sea, but these are mere pinpricks in
the vastness of this environment. The understanding
of the deep-sea ecosystem is entwined with some of
the most exciting aspects of scientific exploration and
with the development of technologies for sampling
and penetrating this environment. This volume is a
status report, at the beginning of the 21st century, on
current knowledge of the deep sea, on how perceptions
of it have changed and where the exciting scientific
discoveries will be made in the future.
CHANGING PARADIGMS
Explorers and commercial interests have used the sea
as a means of transport for millennia. However, they
always looked to the horizon, and it was only in the
latter part of the 19th century that scientists went to
sea with the specific aim of looking downwards into
the impenetrable depths.
One of the first was Forbes (1844), who sampled
down to a depth of 600 m in the Aegean. Today
one would consider this choice of sampling station
as unfortunate, since this region of the Mediterranean
deep sea is faunistically very poor, and the lack
of animals in Forbes’s samples led to the ‘azoic
theory’ that little or no life existed below 600 m.
The establishment of such a paradigm was in direct
opposition to observations of the ophiuroid Astrophyton
being brought up on a sounding line from a depth of
1800 m in Baffin Bay (Tyler, 1980), and the pioneering
work of Michael and G.O. Sars in Norwegian fjords
(Sars, 1864, 1868).
Establishing the presence of a fauna in the deep sea
presented irresistible challenges to a small group of
scientists led by Charles Wyville Thomson. WyvilleThomson used HMS Porcupine to sample the ocean
to the northwest of Scotland and to the west of
Ireland in the late 1860s, and found a fauna at depths
exceeding 4000 m (Thomson, 1873). This series of
cruises established the first ecological observation in
the deep sea by showing that there was a marked
temperature difference associated with faunal change
as one moved across what is now called the Scotland–
Faroes–Iceland Ridge from the warm deep North Atlantic to the cold deep Norwegian Sea (see Chapter 6).
The results of the Porcupine sampling programme
led directly to the HMS Challenger expedition of
1872 to 1876. This expedition traversed the oceans of
the globe and demonstrated a widespread and varied
fauna in the deep sea, as well as taking numerous
physical and chemical measurements. The results of
this cruise, now considered the forerunner of modern
oceanography, were published in a series of detailed
volumes edited by, and at the expense of, John Murray.
A readable account of the Challenger expedition has
been published by Linklater (1972).
The Challenger expedition led directly to the
‘heroic’ age of deep-sea exploration, with expeditions
sampling many areas of the world’s oceans (Menzies
et al., 1973; Mills, 1983). The heroic age culminated
in the Danish Galathea expedition of 1950 to 1952,
which demonstrated that life could be found in the
deepest of all the oceans, in the ocean trenches. One
of the main outcomes of this age of exploration was
1
INTRODUCTION
Paul A. TYLER
The largest single ecosystem on earth is the deep
sea. The sea surface occupies ~70% of the surface
of the earth, and 50% of the surface of the earth
is covered by more than 3000 m of ocean, with a
mean depth of ~3800 m. It is the very remoteness
of the deep sea and the difficulties encountered in
its exploration that have resulted in it being one of
the least understood environments on earth. At the
present time there is detailed information about specific
areas of the deep sea, but these are mere pinpricks in
the vastness of this environment. The understanding
of the deep-sea ecosystem is entwined with some of
the most exciting aspects of scientific exploration and
with the development of technologies for sampling
and penetrating this environment. This volume is a
status report, at the beginning of the 21st century, on
current knowledge of the deep sea, on how perceptions
of it have changed and where the exciting scientific
discoveries will be made in the future.
CHANGING PARADIGMS
Explorers and commercial interests have used the sea
as a means of transport for millennia. However, they
always looked to the horizon, and it was only in the
latter part of the 19th century that scientists went to
sea with the specific aim of looking downwards into
the impenetrable depths.
One of the first was Forbes (1844), who sampled
down to a depth of 600 m in the Aegean. Today
one would consider this choice of sampling station
as unfortunate, since this region of the Mediterranean
deep sea is faunistically very poor, and the lack
of animals in Forbes’s samples led to the ‘azoic
theory’ that little or no life existed below 600 m.
The establishment of such a paradigm was in direct
opposition to observations of the ophiuroid Astrophyton
being brought up on a sounding line from a depth of
1800 m in Baffin Bay (Tyler, 1980), and the pioneering
work of Michael and G.O. Sars in Norwegian fjords
(Sars, 1864, 1868).
Establishing the presence of a fauna in the deep sea
presented irresistible challenges to a small group of
scientists led by Charles Wyville Thomson. WyvilleThomson used HMS Porcupine to sample the ocean
to the northwest of Scotland and to the west of
Ireland in the late 1860s, and found a fauna at depths
exceeding 4000 m (Thomson, 1873). This series of
cruises established the first ecological observation in
the deep sea by showing that there was a marked
temperature difference associated with faunal change
as one moved across what is now called the Scotland–
Faroes–Iceland Ridge from the warm deep North Atlantic to the cold deep Norwegian Sea (see Chapter 6).
The results of the Porcupine sampling programme
led directly to the HMS Challenger expedition of
1872 to 1876. This expedition traversed the oceans of
the globe and demonstrated a widespread and varied
fauna in the deep sea, as well as taking numerous
physical and chemical measurements. The results of
this cruise, now considered the forerunner of modern
oceanography, were published in a series of detailed
volumes edited by, and at the expense of, John Murray.
A readable account of the Challenger expedition has
been published by Linklater (1972).
The Challenger expedition led directly to the
‘heroic’ age of deep-sea exploration, with expeditions
sampling many areas of the world’s oceans (Menzies
et al., 1973; Mills, 1983). The heroic age culminated
in the Danish Galathea expedition of 1950 to 1952,
which demonstrated that life could be found in the
deepest of all the oceans, in the ocean trenches. One
of the main outcomes of this age of exploration was
1