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So my name is Kakani Katija,
and I'm a bioengineer.
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I study marine organisms
in their natural environment.
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And what I want to point out,
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and at least you can see this
in this visualization,
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is that the ocean environment
is a dynamic place.
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What you're seeing
are the kinds of currents,
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as well as the whirls,
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that are left behind in the ocean
because of tides
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or because of winds.
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And imagine a marine organism
as living in this environment,
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and they're trying to undergo
their entire lives
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while dealing with currents like these.
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But what I also want to point out
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is that small organisms also create
small fluid motions, as well.
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And it's these fluid motions that I study.
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And we can think about them
like being footprints.
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So this is my dog Kieran,
and take a look at her footprints.
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Footprints provide a lot of information.
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Not only do they tell us what kind
of organism left them,
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they might also tell us something about
when that organism was there,
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but also what kind of behavior,
were they running or were they walking?
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And so terrestrial organisms,
like my cute dog Kieran,
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might be leaving footprints behind
in dirt or in sand,
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but marine organisms leave footprints in
the form of what we call wake structures,
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or hydrodynamic signatures,
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in fluid.
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Now imagine, it's really hard to see these
kinds of structures
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because fluid is transparent.
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However, if we add something to the fluid,
we get a completely different picture.
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And you can see that these footprints
that marine organisms create
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are just dynamic.
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They are constantly changing.
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And marine organisms also have the ability
to sense these signatures.
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They can also inform decisions,
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like whether or not they want to continue
following a signature like this
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to find a mate or to find food,
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or maybe avoid these signatures
to avoid being eaten.
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So imagine the ability to be able
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to not only see
or visualize these kinds of signatures,
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but to also measure them.
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This is the engineering side of what I do.
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And so what I've done is I actually took
a laboratory technique
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and miniaturized it
and basically shrunk it down
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into the use of underwater housings
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to make a device
that a single scuba diver can use.
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And so a single scuba diver can go
anywhere from the surface to 40 meters,
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or 120 feet deep,
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to measure the hydrodynamic signatures
that organisms create.
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Before I begin,
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I want to immerse you into what
these kinds of measurements require.
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So in order to work,
we actually dive at night,
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and this is because we're trying
to minimize any interactions
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between the laser and sunlight
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and we're diving in complete darkness
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because we do not want to scare away
the organisms we're trying to study.
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And then once we find the organisms
we're interested in,
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we turn on a green laser.
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And this green laser is actually
illuminating a sheet of fluid,
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and in that fluid,
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it's reflecting off of particles
that are found everywhere in the ocean.
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And so as an animal swims through
this laser sheet,
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you can see these particles
are moving over time,
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and so we actually risk our lives
to get this kind of data.
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What you're going to see
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is that on the left these
two particles images
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that shows the displacement
of fluid over time,
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and using that data,
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you can actually extract what the velocity
of that fluid is,
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and that's indicated by the vector plots
that you see in the middle.
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And then we can use that data
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to answer a variety
of different questions,
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not only to understand the rotational
sense of that fluid,
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which you see on the right,
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but also estimate something
about energetics,
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or the kinds of forces that act on
these organisms or on the fluid,
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and also evaluate swimming
and feeding performance.
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We've used this technique on a variety
of different organisms,
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but remember, there's an issue here.
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We're only able to study organisms
that a scuba diver can reach.
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And so before I finish, I want to tell you
what the next frontier is
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in terms of these kinds of measurements.
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And with collaborators at
Monterey Bay Aquarium Research Institute,
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we're developing instrumentation
to go on remotely opperated vehicles
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so we can study organisms anywhere
from the surface down to 4000 meters,
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or two and a half miles.
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And so we can answer really
interesting questions about this organism,
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this is a larvacean,
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that creates a feeding current and forces
fluids through their mucus house
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and extracts nutrients.
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And then this animal,
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this is a siphonophore,
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and they can get to lengths about
half the size of a football field.
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And they're able to swim
vertically in the ocean
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by just creating jet propulsion.
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And then finally we can answer
these questions
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about how swarming organisms,
like krill,
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are able to affect
mixing on larger scales.
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And this is actually one of the most
interesting results so far
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that we've collected
using the scuba diving device
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in that organisms, especially when they're
moving in mass,
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are able to generate mixing
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at levels that are equivalent
to some other physical processes
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that are associated with winds and tides.
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But before I finish,
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I want to leave you all with a question
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because I think it's important
to keep in mind
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that technologies today
that we take for granted
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started somewhere.
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It was inspired from something.
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So imagine scientists and engineers
were inspired by birds
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to create airplanes.
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And something we take for granted,
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flying from San Francisco to New York,
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is something that
was inspired by an organism.
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And as we're developing
these new technologies
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to understand marine organisms,
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what we want to do
is answer this question:
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how will marine organisms inspire us?
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Will they allow us to develop
new underwater technologies,
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like underwater vehicles
that look like a jellyfish?
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I think it's a really exciting time
in ocean exploration
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because now we have the tools available
to answer this kind of question,
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and with the help
of you guys at some point,
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you can apply these tools
to answer this kind of question
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and also develop technologies
of the future.
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Thank you.