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The deep-sea, vastly unexplored,
many consider it Earth's final frontier.
Dark and cold, it was uninhabitable in the belief of many
as recently as a hundred and fifty years ago.
But following ambitious expeditions in recent decades,
researchers have discovered that the
deep-sea environment is bursting with life.
Two researchers at Scripps Institution of Oceanography at UC San Diego
have studied these creatures and helped further our understanding and the
environments in which they reside.
Lisa Levin and Tony Koslow
have probed the deep with a variety of tools and technologies
and often come away with surprising results.
While the deep sea remains of little concern to most,
scientists such as Levin and Koslow say that
influence of humans is reaching into the dark recesses
of the ocean at an increasing rate.
In the early years of deep-sea exploration,
scientists believe that there were only a handful of kinds of species.
They knew all the major groups were down there,
but they really had no idea of how diverse they were.
Once scientists began to take quantitative samples of
in deep water and on the bottom they found
an amazingly large number of species.
One estimate for example is that there are ten million species of very small
animals living in the settlements down there, what we call the Macrofauna.
It's felt that perhaps the diversity rivals
that of tropical rainforest.
We still don't know how that diversity is supported; we do know
now that they're many different kinds of habitats down there that can support
different kinds of life form. We know about seamounts,
now we know about hydrothermal vents, we know the dead animal carcasses like
whales can support specialized
community, and we know that there's methane seeping from the sea floor
that creates specialized communities.
Levin's research includes hypoxic zones--
mysterious sections of the deep-sea where oxygen levels
dwindled to almost nothing. The animals I study
are called the macrofauna. These are animals that are retained on about a
point three millimeter mesh
and they include worms, clams, crustaceans, and
so on. Most of these animals are not tolerant of low oxygen.
The ones that are tolerant are primarily the marine polychaetes--
the worms and these animals have
several adaptations. They have hemoglobin in their blood
that's very good at grabbing oxygen They also have
very elaborate surface area that will have the development of all different
kinds of gills and branchies,
structures that stick out from the body
and make them look essentially that fur balls
and that enhanced surface area provides
basically access to oxygen,
greater surface for diffusion of oxygen into the worms.
Tony Koslow spent a decade studying deep sea life in Australia before
coming to Scripps.
During this time he helped discover new details about the rich marine life
on deep sea mountains called seamounts. He also became acutely aware of the human
threat on the deep,
especially health fishing and trolling devastate deep-sea habitats
including deep-water coral reefs.
The concern is that in fishing these fishes
basically the trolls sweep not only the fish up,
but also whatever else is on the bottom. So they're basically sweeping away these
coral reefs with their with their entire fauna.
There's been a great deal of concern in recent decades
to conserve not only the fish, but also
these deep-water coral reefs. In 2007,
Koslow published The Silent Deep, a book about the discovery,
ecology, and conservation of the deep sea.
He traces the alarming threats from human pollution,
which is finding its way to the deep with increasing regularity
and from climate change as warming waters threatened to make the deep sea
more acidic and reduce oxygen levels.
I came to realize my experience working in the
deep sea,
but the deep sea was not only
much more diverse and
and much more in danger from human exploitation
than people had generally recognized and so
I wanted to basically write about that and bring to people's awareness
what really is the both the
the wonder in the incredible diversity of the deep sea
and also the state of the deep sea. And you know,
we tend to think of the deep sea as being incredibly remote in
and probably the most pristine environment on earth since it is so
difficult to get to,
but in fact it's the last frontier on the planet. Most of these environments have only been
discovered a fan of fifty years
and some of them are in danger
from human exploitation
even before we know very much bout them.
I think what we don't realize
is that without actually visiting the deep-sea
we can be touching it, we can be having an impact on the deep-sea.
What humans have to realize is that any change
along the coastal zone, in surface waters, in circulation,
in temperature, global warming for example,
many, many aspects of climate change have the potential to
influence what's going on down in the deep sea. And while
the effects of the influence may not be felt for
many years to come, the deep sea is part of the larger
cycling of nutrients and materials within the ocean and ultimately we will
feel any changes we make down there.