The views expressed are those of the author and are not necessarily those of Scientific American.Not...

1. Deepsea Challenge Hits Theaters; Here’s the Biology
Behind the Film
The views expressed are those of the author and are not necessarily those of Scientific American.
Note: James Cameron's National Geographic film "Deepsea Challenge 3D" documenting his trip to
Challenger Deep at the bottom of the Mariana Trench has been released at last -- to about 300
"select theaters" on August 8. So far, critics' critiques have been mixed, with some saying that the
movie is lengthy on Cameron and quick on science (although Cameron himself mentioned he would
have liked to see a lot more science in the film, he did not really feel which includes more science
would make the film commercially viable -- though provided disappointing opening weekend ticket
sales the less-science route has not worked out too nicely so far either).
Back in April 2013 I wrote "What Lies at the Bottom of the Mariana Trench? More Than You May
well Believe" -- which I've reposted under -- right after interviewing Natalya Gallo, a member of
Cameron's science team who answered all my questions about the lifeforms Cameron encountered in
the Mariana Trench and the New Britain Trench exactly where the sea trials for the Mariana run
took location. I also watched an American Geophysical Union interview with Cameron and two other
members of his science team and used this and Gallo's interview to reconstruct what we now know
about life in the deepest deep. Even though you will have to watch the film to see pictures of what I
describe below (these have been all hoarded prior to the film's release), if "Deepsea Challenge 3D"
left you thirsty for more about the biology of Challenger Deep, read on.

2. Creative Commons Kmusser. Click image for license and hyperlink.
The deepest, darkest, scariest place on the maps I loved pondering as a child was a crescent-shaped
canyon in the western Pacific Ocean.
It was known as the Mariana Trench, and at the very, really bottom was the lowest point on Earth's
surface, the Challenger Deep. Its floor was seven terrifying miles down.
What was down there? It was entertaining to imagine. I didn't know, and it did not appear probably
any person would anytime soon.
In 1989, James Cameron had enjoyable imagining what may well be at the bottom of a similar
canyon when he produced the "The Abyss", which imagined really a lot at the bottom of an
unspecified Caribbean trench. Eleven-year-old me loved it.
Then, final year, he answered the query for himself.
In February and March, he descended to the bottom of both the New Britain and Mariana Trenches,
lights and three-D Hi-Def cameras blazing, in a slender, lime-green sub referred to as the Deepsea
Challenger. He also dropped a number of autonomous landers constructed on equivalent style.
He wasn't the very first observer, of course. The manned Bathyscaphe Trieste touched down in 1960
and numerous remotely operated automobiles have been there given that. But the Trieste was

3. unable to observe much, and for whatever purpose, little seemed to reach the public about what has
been found because. As I wrote back in February, all footage of the Challenger dives and landers are
getting withheld by National Geographic till their can release their personal three-D function film.
Perfectly understandable, considering they helped bankroll the almost certainly exorbitant
operation.
The result, although, is that right after all these visits to Challenger Deep, the view of the bottom
remains largely and frustratingly shrouded to the rest of us.
When Someone Provides to Inform you What's at the Bottom of the Deepest Spot on Earth, You Say
Yes
A month ago I wrote about about an important presentation at an obscure meeting in New Orleans
by a grad student who worked with Cameron's information. Her name is Natalya Gallo, and she is a
very first-year graduate student in biological oceanography at the Scripps Institute of Oceanography
at UCSD.
Under the supervision of her adviser Lisa Levin, she spent at least 80 hours, and a single may
reasonably infer significantly more, examining the 80 hours of footage brought back by the landers
and sub that James Cameron piloted to the bottom of the New Britain -- located off the coast of
Papua New Guinea -- and Mariana Trenches in February and March 2012. She was looking for
megafauna -- huge animals and other large stuff -- and her job was to identify and count what she
could.
After I wrote final month I hoped a person was in New Orleans to report on her findings (as it turned
toallas Buenas out, no a single was), she graciously contacted me and supplied to inform me about
what she discovered herself. There are days that make this job amazing. The day I got to ask
something I wanted of a individual who was 1 of the couple of folks in the world who knows what is
at the bottom of Challenger Deep was 1 of those days.
Then, although writing up what she told me, I found the American Geophysical Union had posted a
recording of the December 2012 presentation in which Cameron, microbiologist Douglas Bartlett,
astrobiologist Kevin Hardy, and other people presented their findings. It had received only light
media coverage at the time. It was a gold-mine. Most of the imagery was hidden by copyright
protective coverings. But the audio was not. With these two sources in hand, I'll attempt to describe
what this team knows about what's down there.
Are You Going to Consume That?
Sadly, there weren't any kraken lurking in Challenger Deep -- at least not in plain view. But there
have been other interesting items. The big life types that Gallo identified fall into three categories:
gigantic, almost invisible, and actually weird.
In the very first category are amphipods, which are shrimp-lke crustaceans. They're not extremely
glamorous, but they are extremely abundant. Exactly where water is found, so as well are
amphipods. In the Challenger Deep, there seem to be a number of white or pale pink species. You
can see a few starting at 1:01:52 in the AGU video.
What tends to make the Challenger Deep amphipods particular is their size. At the presentation,
Bartlett noted that most ocean-going amphipods are the size of the final segment of your thumb. The
ones that match in the team's traps maxed out at 17 cm. The ones that could not reached 30. That's

4. 1 foot lengthy.
Gallo also noticed on video assessment what looked at first like sticks buried in sand and very
carefully organized in strange patterns. It was only right after watching the tape repeatedly that she
realized she was looking at sea cucumbers -- sea cucumbers so craftily hidden that Cameron had not
even noticed them during his dive. Their shade of beige exactly matched the sandy substrate.
Sea cucumbers are echinoderms like sea stars, and they specialize in roving the abyssal plains of the
world, harvesting food from the sediment with their feeding appendages. Others web site themselves
to intercept ocean currents, and catch items that drift by on their feeding tentacles.
The cucumbers of the Challenger Deep were of the second sort. Sea cucumbers like them were
dredged from the trench by Soviet trawlers at least as far back as the 1950s, Bartlett said, but the
Soviets' specimens have been smaller sized.
And Soviet trawls were unable to observe their peculiar bottom behavior. Within the same group,
the sea cucumbers have been all pointed in precisely the exact same direction, a strategy seemingly
calculated to maximize the harvest of the few nutrient-bearing ocean currents that reach the bottom.
The cucumbers also appeared to be frozen in location. The only factor that ever seemed to move,
Gallo stated, had been their feeding appendages.
If Life Offers You Sand, Make a Sand Castle
The final big creature that Cameron's cameras observed in the Challenger Deep is almost certainly
not one you would recognize as becoming alive at all. Yet they had been the most abundant residents
of the Deep, reaching concentrations of much more than 20 per two minute sample of film.
Gallo described them as "crushed sand castles" jutting from an otherwise featureless mechas
californianas plain. The year before Cameron made his dive, Scripps and National Geographic
released a drop cam into the Sirena Deep, an additional component of the Mariana Trench. The
resulting video ought to give you a somewhat fuzzy concept of their appearances. (It also shows
there's at least one other huge resident of the Challenger Deep: a jellyfish.)
Someplace inside those unstable, irregular piles of sand, a giant, filamentous protist known as a
foraminiferan lives.

5. A live foram from San Francisco Bay. The filamentous pseudopods are clear. The shell covers the
organism. Inventive Commons Scott Fay click image for license and hyperlink.
Foraminifera -- usually called forams -- are amoeba-like protists. Most forams sprout filamentous,
sticky branched pseudopods with which they snag food. They frequently develop calcium carbonate
shells (technically, "tests") -- usually of great complexity and beauty -- through which they poke said
pseudopods. They crawl through the sea sediments of the globe snaring prey and usually raising
hell.
At the bottom of Challenger Deep, calcium carbonate shells are not an option since the intense
pressure -- over 1,000 times sea-level -- dissolves the mineral. Not a issue. The microscopic forams
down there make soft shells, presumably of protein or other organic polymers. The Japanese rover
KAIKO found over 400 species of soft-shelled forams living in the sediment of Challenger Deep in
2005.
But there's another choice: glass. Sand grains -- typically made of silicon dioxide, the main
constituent of glass* -- withstand Mariana-class pressures. The shells of deceased diatoms and some
radiolarian skeletons are also made of silicon dioxide. Ocean sediment has sand grains, cast-off
shells, and microbial skeletons to spare. If you can glue those puppies collectively -- perhaps along
with some of your own handy fecal pellets -- you have got yourself the makings of a pressure-proof
shell. Often, not much of a "shell". But a shell nonetheless.
And that is specifically what the xenophyophores at the bottom of the Mariana do. Unfortunately,
their sand-shell shanties, though pressure proof, are frequently not specifically sturdy, thwarting
most collection attempts therefore far. As a result, we know a lot significantly less about their
biology than we would like. We do know they reside all more than the planet at fantastic depth, and
seemingly, the deeper and a lot more hostile the environment, the much better.
Xenophyophores trap and eat tiny particles by engulfment, as correct "amoebas" do. They had been
not distributed evenly in the trench -- some areas have a lot more and some significantly less. The
giant protists, Gallo says, are most likely siting their properties -- as the sea cucumbers outlet online
do -- to maximize existing-borne meals extraction. As the currents encounter their lumpy dwellings,
the water slows and particles drop out.

6. Inside the sand shanty is a branched collection of tubular filaments that has numerous nuclei and no
cell partitions, leading some to describe them as among the biggest "single-celled" organisms on
Earth. Plasmodial slime molds -- landlubbing crawling bags of cytoplasm of which I am enormously
fond -- are also contenders for that title.
But according to Christopher Taylor at the Catalogue como eliminar celulitis de las piernas of
Organisms, the idea that xenophyophores are giant amoebas or the world's biggest cells is a bit
misleading. Describing them as giant amoebas is not actually correct if they are more of a tubular
network. They are only giant cells if you also consider filamentous fungi like zygomycetes that lack
cell-wall partitions (the bio-term is "coenocytic") to be giant cells also. As with so much in biology,
Taylor has pointed out, the boundary among single-celled and multi-cellular is not so apparent as
you may well feel.
In my personal judgment, xenophyophores appear to be claiming a marine niche comparable to the
terrestrial niche occupied by lichens. That is, they specialize in taking spots that are so harsh that
they have almost no competition for their residence. Interestingly, each lichens and xenophyophores
also have filamentous bodies and shield themselves with chemical substances or foreign objects
(there are some lichens that really reside *inside* rock and only pop out out to reproduce), even
though this might be pure coincidence.
Gallo estimates there could be 50-one hundred species of xenophyophores in the Challenger Deep.
The Real Challenger Deep Party Scene is Microbial
Bacteria and archaea had been not the focus of Gallo's study, but I'd be remiss not to mention the
current discovery that bacteria thrive in the sediments of Challenger Deep -- and are discovered
there in even greater abundance than on the surrounding abyssal plain. Bacteria aren't the only
microbes, and I earlier noted the hundreds of microscopic foraminifera species identified there. The
authors of this study -- Ronnie Glud et al. at the University of Southern Denmark -- hypothesize that
the canyon walls act as a nutrient funnel that concentrates bacteria chow in the trench. Why that
nutrient enrichment doesn't appear to extend to the top of the food chain, I do not know.
The Cameron group also discovered there are bacteria in the Mariana Trench that blur the boundary
among micro- and macroscopic. At the AGU meeting, astrobiologist Kevin Hand described what he
known as "an astonishingly bizarre microbial ecosystem" on talus blocks in the Sirena Deep (where
the drop-cam video of the xenophyophores was taken). There, one of the remote landers filmed dark
brown, shag carpet-like bacterial mats sprouting from rocks on the floor. You can see images of
them at 1:26:55 and 1:27:12 in the AGU presentation.
These bacteria look to be living off of the products of a spontaneous, ambient-temperature chemical
reaction in between rock and seawater. The mats are composed mainly of bacteria referred to as
Paracoccus denitificans, which look to be the primary producers in the program, feeding on
hydrogen and methane released by seawater-induced serpentinization of the rocks on which they are
expanding. The other bacteria in the mat appear to be the beneficiaries of trickle-down economics
from the Paracoccus program.

7. So significantly for the Challenger Deep. Given that our bottom time in hours is almost certainly
nonetheless in the double digits down there, I am certain there are nevertheless surprises waiting.
But realizing this much is nevertheless enormously exciting.
It is Raining Meals
The New Britain Trench -- which
Cameron visited as a test-run for
Mariana -- which at eight,200 meters
deep is only two,700 meters shallower
than Challenger Deep. But life there was
really different. The trench bottom was
home to an array of sea cucumbers,sea
anemones, jellyfish, comb jellyfish, and
giant amphipods. On the walls of the
trench have been hundreds of white,
slender stalked anemones.
Unlike the sea cucumbers of the
Mariana, the sea cucumbers of New
Britain appeared to be crawling in all
directions, sifting the sediment for food,
and they dominated the community. The
cameras even saw sea pigs, a types of
leggy pink sea cucumber sporting
tentacles and a frilly Liberace-style feeding apparatus. Sea pigs travel in herds across the abyssal
plains of the planet, and do, in fact, resemble a pig.
Acorn worms have been also abundant at the bottom of the New Britain. These peculiar worms are
of particular significance to us. You may know that echinoderms -- like sea stars, sea cucumbers, and
sea pigs -- are the group of animals most closely associated to our own group, the chordates, animals

8. with a dorsal nerve cord.
Acorn worm larvae strongly resemble echinoderm larvae. And adult acorn worms -- with each other
only with chordates -- have gill-like pharyngeal slits for breathing and feeding. They also have a
hollow nerve cord not unlike our own. Hence, it looks like acorn worms, echinoderms, and chordates
all shared a typical ancestor. The informal name for acorn worms -- hemichordates -- hints as much.
There is Some thing Unique about three.7 Kilometers
Although this post is about trench bottoms, trench walls can also be intriguing. Halfway down the
New Britain Trench the cameras encountered a strange community not observed above or under. At
the top and bottom of the trench, the huge animals lived on the surface of the sediment. But for
some purpose, about three.7 km deep, most animals lived in the sediment. This community had been
previously observed off the coast of Chile at a equivalent depth, Gallo mentioned, so there appears
to be some thing unique about the depth.
Right here, the sand was covered in hundreds, if not thousands, of strange circular patterns in many
sizes and shapes. Gallo described them as "rosettes" or a like a spoked wheel with out a rim
Cameron called them "starbursts". Some have been completely spherical. Some have been slanted in
a single path. Some overlapped. She counted over one hundred in a 2-minute film sample.But what
are they?
They did not handle to catch the animal that created them on film. But scientists know from other
marine environments that the strange sand art is the solution of animals known as spoon worms.
Spoon worms belong to the group of segmented worms referred to as Annelids. Earthworms are the
most familiar member of the group. The sand pattern size differences appear to indicate a selection
of ages and species are present.
Spoon worms have added to the fundamental annelid body plan a proboscis, which Gallo described
as a "tongue".

9. Edible spoon worms at a market in Korea. The probosci and resemblance to earthworms are also
evident. Some spoonworms can be brightly colored, however. Inventive Commons J. Patrick Fischer.
Click image for license and hyperlink.
The proboscis seems to lick or comb sediments for food, maybe whilst their bodies remain
comfortably ensconced in the security of their burrow in the center of the diggings. The worms may
have great purpose for caution. Two-and-a-half foot extended lizard fish -- large for the depth -- had
been observed right here also, and might keep an eye out for spoon worm snacks.
With each other Gallo and I tried to find any
image of these rosettes from other ocean web
sites on the web to share with you here. We
failed. "All I can see at these dive sites is
thousands of these rosettes," she mentioned,
"and there's not even a single image." It is,
perhaps, worth pondering this in light of the
cornucopia of photos available of the moons
and planets of our solar method.
What they did not see in either trench had
been any trilobites, fascinating armored and
calcite-lensed creatures that dominated Paleozoic oceans, and have long been thought extinct. Sorry,
Brian Switek (and me also, for that matter).
A Tale of Two Trenches

10. Gallo and her group reached several conclusions from her hours of trench gazing. A single, she
stated, was that biodiversity decreases with depth. This is unsurprising, since food follows the same
curve.
The team's most crucial discovering was this: clearly, there is no 1 "trench-bottom neighborhood".
But why were the communities of http://wiki.answers.com/ the two trenches so distinct? Based on
what scientists know so far, the tale of these two trenches is a story of food.
The New Britain Trench
http://blogs.discovermagazine.com/discoblog/category/diseases-injuries-other-ailments/page/30/ is
near Papua New Guinea, and a lot of crap from land ends up down there. Gallo saw palm fronds,
leaves, sticks, and even coconuts at the bottom.
But one ecosystem's trash is another ecosystem's treasure, and nowhere is that truer than in a
trench. Many of the sea anemones, soft corals, and stalked echinoderms referred to as crinoids (also
called feather stars or sea lillies) in the New Britain Trench employed the debris that fell into
vestidos de comunion the depths as a supply of meals and base of operations. In turn, they attracted
crustaceans and fish to the mounds.
Far out in the western Pacific, there is significantly less to consume. Land is far away, and the
waters above the Mariana Trench are not particularly productive, Gallo said. The macroorganisms
that live on the bottom need to be masters at surviving on scraps. Only a handful of large life types
can capitalize on the circumstances. But they do, and judging by their abundance, life's not as well
bad, pesky Japanese rovers and National Geographic explorers notwithstanding.
This insight tends to make the prospect of further exploration extremely exciting. The evidence so
far suggests that each and every trench could have a personality. It suggests that unexplored
trenches, due to local constellations of temperature, nutrients, geology, salinity, chemistry, etc., may
contain species and ecosystems we have yet to picture.
In other words, every unexplored ocean trench
http://blogs.discovermagazine.com/discoblog/category/diseases-injuries-other-ailments/page/30/ is a
surprise package waiting to be unwrapped. And somewhere, somehow, trilobites -- or one thing even
more wonderful -- could nevertheless be awaiting the pop of flashbulbs and champagne bottles. Let's
go.
______________________
*four/15/13 Clarification: Even though sand's silica is often in the kind of crystalline quartz, rather
than amorphous glass, as per David Bressan's comment at the original post.