2
Paul A. TYLER
the publication of descriptions of the fauna collected
on these voyages.
Taking stock of deep-sea ecology at this point in time
would have led to the establishment of the following
paradigms:
• The deep sea was species-poor.
• It was a tranquil quiescent environment.
• There was a slow rain of material from surface to
the deep (although see Moseley, 1880).
• No primary production occurred within the deep
sea.
The 1960s heralded a new approach to deep-sea
ecology, driven by technology. Quantification became
the name of the game, and to get accurate data it
was necessary to replace the coarse-meshed qualitative
sampling gear of the heroic age with more refined
quantitative gear. This was initially achieved by Howard
Sanders and Robert Hessler from the Woods Hole
Oceanographic Institution, who used an anchor dredge
(later an anchor box dredge: Gage and Tyler, 1991) to
sample a series of stations down to a depth of 5000 m
between Gay Head, Massachusetts and Bermuda. The
fine mesh of the anchor dredge collected a wide variety
of species, many new to science, which had been
missed by the coarse dredges of the heroic age. Thus
the concept of high biodiversity in the deep sea was
established, although the absolute diversity is still very
much subject to debate (see Chapter 10); but it is now
believed that the deep oceans are as diverse as tropical
rain forests.
Although known to be diverse, it was assumed
that the deep-sea system was heterotrophic, relying on
the slow sinking of material from surface waters to
provide an energy source for the inhabitants. The 1970s
and 1980s provided evidence that this environment
was more dynamic than originally thought. The first
example was the discovery of hydrothermal vents
along the Galapagos Ridge in 1977 (see Chapter 4).
For the first time there was evidence that primary
production could take place within the deep sea,
and an ecosystem independent of sunlight had been
discovered. This discovery led to one of the most active
programmes in deep-sea biology, and the discovery of
hydrothermal vents continues to this day. There can be
few people interested in the natural environment who
have not seen photos or videos of these spectacular
environments. Subsequently, a second type of primaryproduction environment was observed in the form of
cold seeps (see Chapter 4). Both hydrothermal vents
and cold seeps are driven by the availability of reduced
chemicals such as hydrogen sulphide and methane, the
main difference being the temperature of emission.
In terms of energy availability a parallel, but no less
important, revolution was occurring in understanding
the input of material from surface primary production.
The concept of the slow rain of surface primary production to the seabed was challenged by technological
advances, particularly in the use of sediment traps
to collect the sinking material. Such sediment traps,
together with other techniques (see Chapters 2 and 11)
showed that, particularly at temperate latitudes, surface
production sank rapidly to the seabed – on average, at
a rate of ~100 m d
−1 . As a result, the signal of seasonal
surface production was transmitted to the seabed, and it
is now known that a number of organisms on the deepsea bed respond seasonally to this input. This theme is
explored in many chapters in this volume.
This seasonal perturbation is mild in comparison to
the last major shift in paradigms. Over certain areas
of the seabed, especially under areas of high surfaceeddy kinetic energy, benthic storms are created by
the input of energy to the seabed. These storms are
analogous to the blizzards of Antarctica. They create
strong currents transporting sediment, which is then
deposited in drifts on the seabed, smothering the local
fauna (see Chapter 2).
Lastly, technology has allowed humans to penetrate
this ‘remote’ environment. SCUBA diving is limited to
the top 30 m of the water column; but the development
of submersibles has allowed scientists to dive to the
deep-sea bed and conduct manipulative experiments
as though they were working at the laboratory bench.
Current knowledge of hydrothermal vents and cold
seeps would be insignificant if it were not for the
submersible. Submersibles are still used today; but the
Remote Operated Vehicle (ROV) allows similar access
from the comfort of the surface tender without the
potential dangers of manned submersibles.
Today one may summarize the paradigms for the
deep-sea environment as:
• High species diversity.
• Periods of benthic storms perturbing an apparently
gentle environment.
• Seasonal input of surface-derived energy for heterotrophic organisms.
• Primary production at vents and cold seeps.
The change in understanding of the deep sea has
been a function of an increase in the ability of scientists
to gain knowledge from this environment. Despite
recent recognition of the above paradigms, all of them
Paul A. TYLER
the publication of descriptions of the fauna collected
on these voyages.
Taking stock of deep-sea ecology at this point in time
would have led to the establishment of the following
paradigms:
• The deep sea was species-poor.
• It was a tranquil quiescent environment.
• There was a slow rain of material from surface to
the deep (although see Moseley, 1880).
• No primary production occurred within the deep
sea.
The 1960s heralded a new approach to deep-sea
ecology, driven by technology. Quantification became
the name of the game, and to get accurate data it
was necessary to replace the coarse-meshed qualitative
sampling gear of the heroic age with more refined
quantitative gear. This was initially achieved by Howard
Sanders and Robert Hessler from the Woods Hole
Oceanographic Institution, who used an anchor dredge
(later an anchor box dredge: Gage and Tyler, 1991) to
sample a series of stations down to a depth of 5000 m
between Gay Head, Massachusetts and Bermuda. The
fine mesh of the anchor dredge collected a wide variety
of species, many new to science, which had been
missed by the coarse dredges of the heroic age. Thus
the concept of high biodiversity in the deep sea was
established, although the absolute diversity is still very
much subject to debate (see Chapter 10); but it is now
believed that the deep oceans are as diverse as tropical
rain forests.
Although known to be diverse, it was assumed
that the deep-sea system was heterotrophic, relying on
the slow sinking of material from surface waters to
provide an energy source for the inhabitants. The 1970s
and 1980s provided evidence that this environment
was more dynamic than originally thought. The first
example was the discovery of hydrothermal vents
along the Galapagos Ridge in 1977 (see Chapter 4).
For the first time there was evidence that primary
production could take place within the deep sea,
and an ecosystem independent of sunlight had been
discovered. This discovery led to one of the most active
programmes in deep-sea biology, and the discovery of
hydrothermal vents continues to this day. There can be
few people interested in the natural environment who
have not seen photos or videos of these spectacular
environments. Subsequently, a second type of primaryproduction environment was observed in the form of
cold seeps (see Chapter 4). Both hydrothermal vents
and cold seeps are driven by the availability of reduced
chemicals such as hydrogen sulphide and methane, the
main difference being the temperature of emission.
In terms of energy availability a parallel, but no less
important, revolution was occurring in understanding
the input of material from surface primary production.
The concept of the slow rain of surface primary production to the seabed was challenged by technological
advances, particularly in the use of sediment traps
to collect the sinking material. Such sediment traps,
together with other techniques (see Chapters 2 and 11)
showed that, particularly at temperate latitudes, surface
production sank rapidly to the seabed – on average, at
a rate of ~100 m d
−1 . As a result, the signal of seasonal
surface production was transmitted to the seabed, and it
is now known that a number of organisms on the deepsea bed respond seasonally to this input. This theme is
explored in many chapters in this volume.
This seasonal perturbation is mild in comparison to
the last major shift in paradigms. Over certain areas
of the seabed, especially under areas of high surfaceeddy kinetic energy, benthic storms are created by
the input of energy to the seabed. These storms are
analogous to the blizzards of Antarctica. They create
strong currents transporting sediment, which is then
deposited in drifts on the seabed, smothering the local
fauna (see Chapter 2).
Lastly, technology has allowed humans to penetrate
this ‘remote’ environment. SCUBA diving is limited to
the top 30 m of the water column; but the development
of submersibles has allowed scientists to dive to the
deep-sea bed and conduct manipulative experiments
as though they were working at the laboratory bench.
Current knowledge of hydrothermal vents and cold
seeps would be insignificant if it were not for the
submersible. Submersibles are still used today; but the
Remote Operated Vehicle (ROV) allows similar access
from the comfort of the surface tender without the
potential dangers of manned submersibles.
Today one may summarize the paradigms for the
deep-sea environment as:
• High species diversity.
• Periods of benthic storms perturbing an apparently
gentle environment.
• Seasonal input of surface-derived energy for heterotrophic organisms.
• Primary production at vents and cold seeps.
The change in understanding of the deep sea has
been a function of an increase in the ability of scientists
to gain knowledge from this environment. Despite
recent recognition of the above paradigms, all of them