Welcome to the Environment Show Exploring Issues and Events of the Planet.
I'm Thomas Lalley.
The Environment Show is a national production made possible by the David and Lucille Packard
Foundation.
Your host is Peter Burley.
Thanks Thomas.
Coming up on this week's Environment Show.
We're going underwater and will hear the rumble of volcanoes on the ocean floor and the
voices of whales hundreds of miles away, sounds that have never been broadcast on radio
before.
We'll talk to scientists who are learning incredible things about what's in the ocean,
using a secret eavesdropping system the Navy built to track Soviet submarines.
Author Tom Horton takes us to Chesapeake Bay in Maryland where Krabber is meditative over
an underwater jungle.
The Earth calendar looks at the unique breeding process of sand sharks.
These stories are more coming up this week on the Environment Show.
About 30 years ago, the United States Navy started building a secret underwater spy network
known as the Sound Surveillance System or SOSUS.
The system, which ultimately costs $16 billion, consists of hundreds of microphones placed
underwater and connected by thousands of miles of cables.
The cables transmit the sound to land stations.
For example, the Navy listens to sounds from the entire North Pacific Ocean all the way
to the Russian coast if their basin would be island, not far from Seattle, Washington.
The idea is to track Soviet submarines 24 hours a day wherever they are.
About four years ago, the Navy proposed to do some tests by tracking loud sounds that
it would make underwater.
A question then arose about whether these tests would have an impact on whales.
At that point, the Navy went to a civilian scientist, Dr. Christopher W. Clark, director
of the Bioacoustics Research Program at Cornell University and gave him access to some of
the Atlantic tapes.
Much of the sound is at a very high decibel level and at a very low frequency.
You'll hear some of it now, played for the first time ever over radio.
It's been sped up by a factor of ten or more so it's audible to the human ear.
Well if one had the lung capacity and the right kind of anatomy and you could dive down
to the bottom of the deepest trench in the Atlantic Ocean, the Pacific, sorry, you could
dive down to the deepest trench in the Atlantic Ocean, the Puerto Rican trench, 50, 75 miles
north of Puerto Rico and the Virgin Islands.
And you placed yourself in this trench and now you're thinking of yourself as a giant
and your ears are spread apart over, say, a hundred miles and you could now hear the
moaning and stretching of the Earth's crust and that would sound much like the rumbling
of a summer thunderstorm, a constant that is rumbling and cracking and groaning, almost
like bowling ball sometimes rolling over your head.
And on top of that there is a caffiny of melody and if you're lucky on a good day you
will also hear thinback whale which produced very rhythmic sequences of pulses that remind
you of drummers or L tapping at a very regular interval.
And then way in the distance you'll hear the mournful, almost owl-like sounds of blue whales.
And you can hear blue whales in the Puerto Rican trench and those blue whales will literally
be off of Nova Scotia or Northamond.
That's far away and you'll hear their sounds coming in almost ghost-like and across the
ocean.
Starting in 1933 the Navy began making tapes available to researchers studying undersea
volcanic eruptions and whales.
Analyzing data from the SOSA system Steve Hammond manages a program of a National Oceanic
and Applesfairic Administration which is measuring underwater volcanic activity.
We're looking at virtually the entire Pacific.
There are places in the Pacific that are shadowed by island arc systems or island systems.
But we're looking so to speak at virtually the entire Pacific and we're doing this in
real time and we're doing it continuously.
Hammond says 80% of the volcanic activity on the earth takes place 1 to 3 miles beneath
the surface of the ocean and during 3 years of his studies there's been about one major
eruption a year.
Previously these had been undetected.
We're finding eruptions in some strange places but you have to remember that even though
this is the largest volcanic system on the planet until 1993 no one had ever detected
and located and studied one of these eruptions while it was active.
Even though it's the most common kind of eruption on earth no one had been there while
it was going on before.
The volcanic activity occurs along geological structures known as seafloor spreading systems
which thread through the oceans like the stitching on a baseball.
The effects of these volcanic eruptions are unknown on the surface but using acoustical
data the researchers for the first time can locate an eruption reach it by ship and take
samples of the water column above it.
In some parts of the ocean floor there are vents that gush heat and chemicals continuously.
These vents are also located by sound.
One way to visualize these is just simply to think about Yellowstone Park being placed
on the bottom of the ocean.
That's what these hot springs are like but the water is very much hotter because of the
overlying pressure of the ocean.
The water not infrequently exceeds 400 degrees centigrade and it's not boiling.
Hammond tells us that research on the seafloor has led to amazing discoveries of new forms
of life in unimaginable quantity.
We discovered within the past few years that there is actually a very large biosphere that
exists beneath the seafloor in the plumbing system if you will of these seafloor volcanoes
where the hot water and magmas are circulating in the seafloor.
In those areas there are immense quantities of bacteria that it's estimated now that
if you scoop them all out somehow and weighed them they would actually amount to.
That would be a larger mass than all of the living creatures on the continent.
It's a very, very large community, a very primitive, very exotic microorganisms.
These microorganisms are beneath the floor in cavities and tunnels and so on, is that correct?
Yes, these microorganisms, these bacteria are living in the cracks and crevices of the
rocks where the hot waters are circulating and where they can have access to the nutrients
in these fluids.
They presumably function without any form of light at all.
Yes, these organisms are chemo autotrophic or organisms.
They don't care whether the sun is shining or not.
They live using a chemistry that's dependent on nutrients within the hydrothermal fluids.
The microbiologist that we are working with tell us that the discovery of this huge ecosystem
that lives beneath the seafloor is akin to finding life on another planet.
It's akin to discovering a whole new rainforest ecosystem in terms of its potential biotechnical
and biochemical applications.
Steve Hammond is the program manager for the NOAA Vence Program and his research tells us
that whoever described the ocean depths as silent had never been there with a hydrophone.
When Christopher Clark of Cornell first heard the tapes, thousands of miles of ocean opened
up to him at once.
Before this technology was available, scientists explored oceans piece by piece, but now they
can hear what's going on in spaces the equivalent of Asia, Africa, North America, and Europe
all put together.
He says when he first heard the tapes, he knew history was being made.
The amazing thing that I discovered when I listened to the tapes were that no matter which
tape I pulled off the shelf and I was randomly pulling them off the shelf, every tape had
whales on it.
And there were multiple signatures, if you will, indicating different species.
And these were signature types that had been very poorly, if at all, described in the scientific
literature.
Clark began following one whale sound, which he called Old Blue, and found that it could
be tracked over many hundreds of miles.
Old Blue was easily distinguishable from other sounds like passing ships and other whales
because of its pattern and course.
Scientists now easily distinguish between numerous species of whales.
Dr. Marilyn Dolheim is with the National Marine Fisheries Service in Seattle, Washington.
She says the material from SOSIS is answering many questions scientists have had about
whales.
If you do this seasonal progression of sounds, you can actually determine migration routes
of whales and also there are habitats that they require.
Now the thing that we're really excited about and we're just launching into that at this
point in time is that what we'd like to do is produce these call density maps for different
seasons for different species and then overlay the physical oceanographic information on top
of that.
And with that information we might get more ideas of what these whales habitat requirements
are.
And I think that's very, very important for our knowledge about whale distribution and
migration and life history parameters.
Whales have lived in the oceans for about 30 million years.
In that time they've evolved to take advantage of the ocean's unique acoustical qualities.
Even though whale sounds are incredibly loud, humans can hardly hear them.
That's because they're well below sounds that we're used to hearing.
But Christopher Clarke says that's the perfect place for them.
Sound in the ocean travels extremely far because the ocean is a denser environment than air.
Air is very thin.
I mean here we can just wave our arms around in the air without a problem but if you try
waving your arm around the ocean you feel a lot of resistance.
And once it gets into the ocean you can travel extremely great distances.
And especially so if the sound is low.
And it's not by chance that the voices of blue and thin whales which are the loudest voices,
natural voices, known to humans.
But these sounds are selected to occur right at the frequencies which travel the greatest
distance in the ocean.
So a blue whale that's producing a sound of 185 decibels.
And this would be of an intensity, of an energy equivalent to a jet engine.
I mean these are very loud sounds.
If that sound propagates through the ocean and gets trapped in the deep sound channel
it literally can go from Newfoundland down to Puerto Rico.
One of the problems faced by Clarke and Dohaim is the sheer volume of noise.
What does it mean?
What are the whales saying?
And how many whales are out there?
Dohaim says they're still trying to get a handle on the avalanche of information, literally
gigabytes of data coming in each day.
Although Sussex has provided answers, it's also revealed many new questions.
For instance, whales have been found doing mysterious things in places scientists never
expected to find them.
Humpbacks have been recorded singing 24 hours a day for days on end.
And blue whales have been found between San Francisco and Hawaii in winter when waters
are frigid and turbid.
Christopher Clarke says these revelations have advanced our knowledge of the ocean by
late years.
When you can sit in one place and listen to an entire ocean basin day after day after
day, it's just awe inspiring.
One of the preconceptions, the strongest preconceptions that we've all had, has been
dictated by where humans have been able to go in both.
Sussex has done, has underscored the fact that much, if not most, of the vocal activity.
And we're whales, especially the big whales, like blue whales and thinback whales, are
performing this activity, is in the open ocean, it's in the deep ocean.
Clarke says that while Sussex has expanded our view of the oceans, it is also highlighted
our lack of understanding.
He says we're trying to manage oceans without knowing what's in them or what ramifications
we're having.
Like so many military programs, Sussex opened a vast horizon for science.
Imagine hearing everything going on in a whole ocean all at once.
But the scientific potential has only been partially realized.
Until 1993, the Navy filtered out all natural sounds, focusing on ships and submarines.
They then discarded the tapes.
During the last three years, natural scientists say they've gotten more data each week
than they could collect previously in a year.
But with a cold war over, the system is being phased out to save huge maintenance costs.
It takes a million dollars to repair a cable and they're cut periodically by fishing activities.
So the civilians that scientists are in a race against time to collect and analyze all
the sounds of the sea before they lose the most extensive eardropping system ever devised.
We all have places which are special to us.
It could be a city block or a place deep in the wilderness.
The oceans and waterways of the earth have always been revered for their beauty, awesome
power and mystery.
From Horton is the author of an island out of time, a book about the lives and places
near Smith Island at the Chesapeake Bay.
He presents a portrait of the place cravers who have worked the fertile bay for hundreds
of years.
In late summer, the craber works the shallows that surround Smith Island for miles.
He uses his long-handled dip net to shovel long standing and hang ten surfer style on
the bow tip of his little flat bottom skiff and tent as any stalking heron on the mating
crabs, male and female, coupled amid the camouflage of the underwater grasses.
The only sounds are the cries of goals and turns and the liquid-crush and verbal of water
beneath the skiff's bow shoved rhythmically to and fro across the flats.
Periodically, the netter stabs with barely a ripple, deftly scooping dubblers as the
copulating crabs are called.
In one fluid motion, he flips each loving pair high in the air and as they separate,
catches the female who will soon shudder shell and turns soft and marketable.
The male is let fall to seek another wife.
Mollett and speckled trout swirled a calm surface and countose rays brought his amans back,
glide alongside the skiff.
In the tawny sunlit shallows once your gaze becomes attuned, the olive crabs stand out
despite their adaptive coloration.
The effect of all this moving beneath your skiff becomes hypnotic, a meditation.
You become absorbed in the minutia of the underwater jungle and with plucking in effect dollar
bills from among its fruited groves.
And then to ease your back and shoulders, you look up at the limitless vault of sky and
out across the broad Chesapeake and feel small as a net amid this serene grandeur of sky
and sea.
And there is a peace, a completeness, a connection that seems to run through you from the
warm and crusted tunnels on the shell of an oyster below to the moon that pulls the
tides through the oyster's gills.
Some days half the townsmen of the island meet like this, 70 to 100 skiff strong.
Elemental as runes, netter and net are the only verticals in a horizontal universe.
As they shove and lean and brace and dip, the crabbers seem to be remancing their slender
poles, waltzing with them languidly to the rhythms of tide in the blue crab.
And to their every move, the skiff follows like a thing alive.
From a distance, the islanders perched on the boughs or Chesapeake's suntars, half man,
half skiff.
Silhouetted against the place where bay and sky merge in a luminous silken monochrome,
suspended in a dream between mud and heaven, between labor and beauty.
It is the prettiest way they know to catch a crab the islanders say.
Tom Horton is the author of an island out of time.
And now it's time for the earth calendar.
Today female tiger sharks are gestating off the US southeastern coast, while their
offspring are devouring each other within their mother's body.
Environment show producer Thomas Laleg reports.
Right now eight to twelve foot sharks are lurking up and down the east coast of the US, foraging
for food.
Sometimes they even come close to shore near where people swim.
And Gilmour is a marine biologist with the Harbor Branch Oceana Graphic Institute in
Fort Pierce, North Carolina.
He studies santae tiger sharks.
He says you don't have to worry about these sharks and most others, even though they share
the same waters we do.
Right now in New York, you will have the males and you will have the last year's young
and maybe some three to four year old fish, too.
Trying to get as large as they can and mature because they need to eat on that very productive
ground off of the middle anticoite.
Like many creatures in the oceans, santae tiger sharks have developed strategies to adapt
to their environment, which includes a most unusual method for reproducing.
Unlike most marine animals, these sharks only produce two offspring or pups each year.
In contrast, blue sharks produce a hundred pups.
With the blue sharks, many pups die, but at least a few survive.
Sandsharks use an alternative method opting to produce two pups, which are about 40 inches
at birth, goliaths of sea infants.
Besides their size, they have an additional leg up on their competition because they're
well acquainted with hunting.
The embryos actually eat each other in the uterus when they're developing inside the
female.
The first embryo to hatch out of the egg actually goes from the uterus and attacks the other
egg capsules that contain embryos and consumes those other embryos.
Now all sharks have two uterine.
They have one on either side.
So this means the santae tiger shark will have two pups or two embryos.
The cannibalism is occurring in each uterus at the same time.
So if I call it a pregnant santae tiger today, and actually July and August is about the
time they go through the cannibalistic phase, we would find embryos developing in both uterine
and then we would see one that has teeth and earlier than the others.
And this particular embryo would then be the first one to hatch and the first one to
start attacking the other embryos.
Gilmore stresses that sharks of all varieties rarely attack humans and when they do, it's
often by mistake.
So for the most part, we're safe.
The same can't be said for the santae tiger shark siblings.
Thanks for being with us this week on the Environment Show.
I'm Peter Burley.
You can write us at 318 Central Avenue, Albany, New York, 1-2-2-06.
For cassette copy of the program, call 1-800-323-9262 and ask for program number 341.
The Environment Show is a presentation of national productions which is solely responsible
for its content.
Tauas Lally is a producer, Stephanie Goysman provided additional production support
and Dr. Alan Shartag is the executive producer.
The Environment Show is made possible by the David and Lucille Packers Foundation.
So long and join us next week for the Environment Show.
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