WEBVTT

00:00:06.563 --> 00:00:10.701
So my name is Kakani Katija,
and I'm a bioengineer.

00:00:10.701 --> 00:00:14.494
I study marine organisms 
in their natural environment.

00:00:14.494 --> 00:00:15.941
And what I want to point out,

00:00:15.941 --> 00:00:18.404
and at least you can see this
in this visualization,

00:00:18.404 --> 00:00:21.453
is that the ocean environment
is a dynamic place.

00:00:21.453 --> 00:00:23.887
What you're seeing 
are the kinds of currents,

00:00:23.887 --> 00:00:25.141
as well as the whirls,

00:00:25.141 --> 00:00:27.671
that are left behind in the ocean
because of tides

00:00:27.671 --> 00:00:29.181
or because of winds.

00:00:29.181 --> 00:00:32.361
And imagine a marine organism
as living in this environment,

00:00:32.361 --> 00:00:34.820
and they're trying to undergo
their entire lives

00:00:34.820 --> 00:00:37.556
while dealing with currents like these.

00:00:37.556 --> 00:00:39.159
But what I also want to point out

00:00:39.159 --> 00:00:43.907
is that small organisms also create
small fluid motions, as well.

00:00:43.907 --> 00:00:46.983
And it's these fluid motions that I study.

00:00:46.983 --> 00:00:49.903
And we can think about them
like being footprints.

00:00:49.903 --> 00:00:54.206
So this is my dog Kieran,
and take a look at her footprints.

00:00:54.206 --> 00:00:56.957
Footprints provide a lot of information.

00:00:56.957 --> 00:00:59.640
Not only do they tell us what kind
of organism left them,

00:00:59.640 --> 00:01:02.899
they might also tell us something about
when that organism was there,

00:01:02.899 --> 00:01:06.409
but also what kind of behavior,
were they running or were they walking?

00:01:06.409 --> 00:01:09.837
And so terrestrial organisms,
like my cute dog Kieran,

00:01:09.837 --> 00:01:14.644
might be leaving footprints behind
in dirt or in sand,

00:01:14.644 --> 00:01:20.848
but marine organisms leave footprints in
the form of what we call wake structures,

00:01:20.848 --> 00:01:22.768
or hydrodynamic signatures,

00:01:22.768 --> 00:01:23.861
in fluid.

00:01:23.861 --> 00:01:26.807
Now imagine, it's really hard to see these
kinds of structures

00:01:26.807 --> 00:01:28.794
because fluid is transparent.

00:01:28.794 --> 00:01:33.844
However, if we add something to the fluid,
we get a completely different picture.

00:01:33.844 --> 00:01:36.938
And you can see that these footprints
that marine organisms create

00:01:36.938 --> 00:01:38.481
are just dynamic.

00:01:38.481 --> 00:01:40.082
They are constantly changing.

00:01:40.082 --> 00:01:43.645
And marine organisms also have the ability
to sense these signatures.

00:01:43.645 --> 00:01:45.955
They can also inform decisions,

00:01:45.955 --> 00:01:49.418
like whether or not they want to continue
following a signature like this

00:01:49.418 --> 00:01:51.492
to find a mate or to find food,

00:01:51.492 --> 00:01:55.421
or maybe avoid these signatures
to avoid being eaten.

00:01:55.421 --> 00:01:57.662
So imagine the ability to be able

00:01:57.662 --> 00:02:01.825
to not only see 
or visualize these kinds of signatures,

00:02:01.825 --> 00:02:03.788
but to also measure them.

00:02:03.788 --> 00:02:06.442
This is the engineering side of what I do.

00:02:06.442 --> 00:02:10.425
And so what I've done is I actually took
a laboratory technique

00:02:10.425 --> 00:02:13.666
and miniaturized it 
and basically shrunk it down

00:02:13.666 --> 00:02:16.115
into the use of underwater housings

00:02:16.115 --> 00:02:19.959
to make a device 
that a single scuba diver can use.

00:02:19.959 --> 00:02:24.231
And so a single scuba diver can go
anywhere from the surface to 40 meters,

00:02:24.231 --> 00:02:25.840
or 120 feet deep,

00:02:25.840 --> 00:02:30.711
to measure the hydrodynamic signatures
that organisms create.

00:02:30.711 --> 00:02:31.568
Before I begin,

00:02:31.568 --> 00:02:36.040
I want to immerse you into what 
these kinds of measurements require.

00:02:36.040 --> 00:02:39.539
So in order to work,
we actually dive at night,

00:02:39.539 --> 00:02:43.866
and this is because we're trying
to minimize any interactions

00:02:43.866 --> 00:02:46.166
between the laser and sunlight

00:02:46.166 --> 00:02:48.775
and we're diving in complete darkness

00:02:48.775 --> 00:02:52.249
because we do not want to scare away
the organisms we're trying to study.

00:02:52.249 --> 00:02:55.085
And then once we find the organisms
we're interested in,

00:02:55.085 --> 00:02:57.708
we turn on a green laser.

00:02:57.708 --> 00:03:01.987
And this green laser is actually 
illuminating a sheet of fluid,

00:03:01.987 --> 00:03:02.989
and in that fluid,

00:03:02.989 --> 00:03:07.219
it's reflecting off of particles
that are found everywhere in the ocean.

00:03:07.219 --> 00:03:10.270
And so as an animal swims through
this laser sheet,

00:03:10.270 --> 00:03:13.971
you can see these particles 
are moving over time,

00:03:13.971 --> 00:03:17.717
and so we actually risk our lives
to get this kind of data.

00:03:17.717 --> 00:03:18.972
What you're going to see

00:03:18.972 --> 00:03:21.593
is that on the left these 
two particles images

00:03:21.593 --> 00:03:24.165
that shows the displacement 
of fluid over time,

00:03:24.165 --> 00:03:26.154
and using that data,

00:03:26.154 --> 00:03:29.195
you can actually extract what the velocity
of that fluid is,

00:03:29.195 --> 00:03:32.756
and that's indicated by the vector plots
that you see in the middle.

00:03:32.756 --> 00:03:34.520
And then we can use that data

00:03:34.520 --> 00:03:36.766
to answer a variety 
of different questions,

00:03:36.766 --> 00:03:39.694
not only to understand the rotational
sense of that fluid,

00:03:39.694 --> 00:03:41.136
which you see on the right,

00:03:41.136 --> 00:03:44.021
but also estimate something 
about energetics,

00:03:44.021 --> 00:03:47.893
or the kinds of forces that act on
these organisms or on the fluid,

00:03:47.893 --> 00:03:50.748
and also evaluate swimming
and feeding performance.

00:03:50.748 --> 00:03:53.888
We've used this technique on a variety
of different organisms,

00:03:53.888 --> 00:03:56.299
but remember, there's an issue here.

00:03:56.299 --> 00:04:00.915
We're only able to study organisms
that a scuba diver can reach.

00:04:00.915 --> 00:04:04.965
And so before I finish, I want to tell you
what the next frontier is

00:04:04.965 --> 00:04:07.950
in terms of these kinds of measurements.

00:04:07.950 --> 00:04:12.287
And with collaborators at 
Monterey Bay Aquarium Research Institute,

00:04:12.287 --> 00:04:16.528
we're developing instrumentation
to go on remotely opperated vehicles

00:04:16.528 --> 00:04:21.799
so we can study organisms anywhere
from the surface down to 4000 meters,

00:04:21.799 --> 00:04:23.495
or two and a half miles.

00:04:23.495 --> 00:04:26.836
And so we can answer really
interesting questions about this organism,

00:04:26.836 --> 00:04:28.547
this is a larvacean,

00:04:28.547 --> 00:04:33.952
that creates a feeding current and forces
fluids through their mucus house

00:04:33.952 --> 00:04:35.949
and extracts nutrients.

00:04:35.949 --> 00:04:37.139
And then this animal,

00:04:37.139 --> 00:04:39.091
this is a siphonophore,

00:04:39.091 --> 00:04:43.072
and they can get to lengths about
half the size of a football field.

00:04:43.072 --> 00:04:46.302
And they're able to swim 
vertically in the ocean

00:04:46.302 --> 00:04:48.452
by just creating jet propulsion.

00:04:48.452 --> 00:04:50.668
And then finally we can answer 
these questions

00:04:50.668 --> 00:04:53.976
about how swarming organisms,
like krill,

00:04:53.976 --> 00:04:57.059
are able to affect 
mixing on larger scales.

00:04:57.059 --> 00:05:01.096
And this is actually one of the most
interesting results so far

00:05:01.096 --> 00:05:04.648
that we've collected 
using the scuba diving device

00:05:04.648 --> 00:05:08.092
in that organisms, especially when they're
moving in mass,

00:05:08.092 --> 00:05:10.365
are able to generate mixing

00:05:10.365 --> 00:05:14.529
at levels that are equivalent 
to some other physical processes

00:05:14.529 --> 00:05:17.359
that are associated with winds and tides.

00:05:17.359 --> 00:05:18.641
But before I finish,

00:05:18.641 --> 00:05:21.500
I want to leave you all with a question

00:05:21.500 --> 00:05:23.840
because I think it's important
to keep in mind

00:05:23.840 --> 00:05:26.919
that technologies today 
that we take for granted

00:05:26.919 --> 00:05:28.424
started somewhere.

00:05:28.424 --> 00:05:30.443
It was inspired from something.

00:05:30.443 --> 00:05:33.950
So imagine scientists and engineers
were inspired by birds

00:05:33.950 --> 00:05:36.191
to create airplanes.

00:05:36.191 --> 00:05:37.863
And something we take for granted,

00:05:37.863 --> 00:05:40.417
flying from San Francisco to New York,

00:05:40.417 --> 00:05:43.440
is something that 
was inspired by an organism.

00:05:43.440 --> 00:05:46.027
And as we're developing 
these new technologies

00:05:46.027 --> 00:05:48.079
to understand marine organisms,

00:05:48.079 --> 00:05:50.398
what we want to do 
is answer this question:

00:05:50.398 --> 00:05:52.965
how will marine organisms inspire us?

00:05:52.965 --> 00:05:56.715
Will they allow us to develop 
new underwater technologies,

00:05:56.715 --> 00:05:59.466
like underwater vehicles 
that look like a jellyfish?

00:05:59.466 --> 00:06:02.543
I think it's a really exciting time
in ocean exploration

00:06:02.543 --> 00:06:06.437
because now we have the tools available
to answer this kind of question,

00:06:06.437 --> 00:06:09.279
and with the help 
of you guys at some point,

00:06:09.279 --> 00:06:12.807
you can apply these tools
to answer this kind of question

00:06:12.807 --> 00:06:15.851
and also develop technologies
of the future.

00:06:15.851 --> 00:06:17.291
Thank you.