Kind: captions
Language: en
healthy coral reefs can be stunningly
beautiful and play a critical role in
coastal
ecosystems they Harbor a tremendous
diversity of marine life and contribute
to the overall health of the world's
oceans and their
coastlines a quarter of all marine
species depend on them for
survival they're also important to
humans often located in shallow water
they can protect Coastal communities
from damaging Storm
surges and the reefs host a primary
sustainable food source for hundreds of
millions of people around the
world but as the oceans warm corals are
struggling to
survive excessive heat drives away the
microscopic algae the coral dependon
that leads to a dramatic loss of color
known as Coral bleaching a powerful
visual indicator of an unhealthy Reef
but bleaching isn't the only indic IND
Ator of a reef in Peril not only it
looks Brown and it's lacking these
beautiful vibrant colors but it just
sounds
dead that's where sensory biologist
Aaron Mooney comes
in my background is in hearing and in
bioacoustics and I study how animals
perceive the world around
them cor Reaves are kind of rainforest
of the sea and just like a really rich
Forest might have a lot of birds calling
and you might hear the monkeys calling
in the background cores are really the
the same so basically a healthy coral
reef has a really healthy Rich
soundscape snapping shrimp Lobster and
fish create a symphony indicative of a
biodiverse
community and a degraded core reef is
just impoverished soundscape it sounds
quiet kind of
desolate so by listening to the
soundscape we can kind of track that
biodiversity and understand when that
change is
happening off the coast of St John in
the Caribbean a team from the Woods Hole
oceanographic institution in
Massachusetts conducts bleaching surveys
finding evidence of degraded
reefs to your right there's some bleach
Coral you knew there was going to be
bleaching here right but then it's
freaking everywhere right I've been
coming here 5 6 years now this was the
first time I've seen such
bleaching Yogi gerar is a roboticist and
computer scientist at Woods Hole I'm
working on robots and Ai and machine
learning based techniques to understand
uh complex ecosystems in the ocean such
as coral
reefs a question they pose is it
possible to build a robot that can seek
out and find healthy Reefs on its
own if they succeed the robot could
provide an efficient and cost-effective
way to find healthy coral reefs map them
and monitor their
health the soundscapes recorded by the
robot could be a vital tool in
diagnosing Reef health and tracking
decline or
Improvement good job
team the team has been collecting data
on reefs for over a decade so you're
going through this yeah you might be
able to thread it through they have
mountains of information including audio
and
video they've even created 3D models of
the reefs for further study helping them
gather this data is this third
generation
robot we call it cury c e uh which
stands for Curious underwater robot for
ecosystem exploration it's equipped with
sensors microphones and cameras and is
still very much under development the
design of a robot is always evolving our
robot is never finished it's an
engineering challenge with a lot of
moving parts so they've broken it down
into many small
steps there are many many problems that
you can solve with an engineering
solution but I think you have to really
understand what the problem is and sort
of pick the two or three that really you
want to address otherwise you kind of
fall into this trap of trying to solve
all the problems all at once and you run
out of
resources this morning the team is
prepping for its latest test right off
the dock all right Dr gerar
ready
always I'll manage the tether got to
start they'll place a speaker on the
ocean floor playing a recording of a
healthy coral reef
a sound file they captured from a
previous trip should be on all right
hear
it they're hoping the robot will
recognize the sound through the water
and be able to record
it in this outing the robot is not
moving
autonomously researcher Seth mccamon is
operating the robot remotely to steer
and position it for the test I'm getting
it in line with the thing so I can start
to look at the data
mhm if it robot doesn't work with this
sound is probably not going to work on
the real cor Reef so it's a good good
test experimenting with sound underwater
is not a new
idea in the 1800s a Swiss physicist and
a French mathematician armed with a bell
and stopwatch measured the speed at
which sound traveled underwater
on one side of Lake Geneva Charles
Francois Stern rang a submerged Bell
while Jean Danielle kodon used a long
tube to listen underwater across the
lake pressing his stopwatch to keep
track of how long it took the sound to
travel across surprisingly they found
that water is a better conduit for sound
than
air sound travels through water roughly
five times faster today the Woods Hole
team will be using the speed of sound
underwater as part of their
calculations the robot is equipped with
four microphones designed for underwater
use called
hydrophones as the sound from the
speaker speeds through the water in all
directions it reaches the hydrophones at
slightly different times just
milliseconds
apart the researchers look at a computer
display that shows the signals recorded
on each hydrophone
and so it'll hit one hydrophone before
the others and by looking at the
relative time of arrival at those
different hydrophones we can figure out
which direction it came from first and
then steer the robot in that
direction the robot correctly identifies
the direction of the sound an important
first step toward autonomous
navigation a small but important victory
it's like you're building out of Legos
and you're building up a house Brick by
Brick by Brick and it only works when
the house is fully done but you need to
know that each single brick in that
works on its own in isolation before
you're willing to add it to the larger
picture and so you have this massive
goal that you're trying to achieve but
there needs to be attainable goals along
the way because ultimately you're
dealing with a system of components a
system of elements that need to work
together in order for this to be
successful
curri is ready to step up to a bigger
challenge locating an actual healthy
Reef by sound something less predictable
than what the speaker provided one of
the healthier reefs in St John is in
nearby Joel's sh I propose that he drop
their by like 20 M we're like 10 m off
the re right now they'll Place cury
approximately 20 M from The Reef to
succeed it just needs to orient itself
toward the sound
robot going
in all right Cast
Away so the test today is mostly just
trying to figure out if the robot can
accurately determine which direction The
Reef sound is in it's a more complex
test this time curri is untethered and
the boat is drifting with the ocean
current if they lose contact they could
easily lose the robot entirely
and all of the engineering that went
into
it when they began to design this
autonomous robot that would go
underwater there is a need to make sure
that this thing is able to behave in an
environment where if it doesn't we can
retrieve
it curri locates the direction of the
healthy Reef which is
encouraging it's another successful
test the next big hurdle can curri not
only locate but then move toward a
healthy Reef
autonomously this will be a crucial
milestone in the mission which is to
ultimately build a fleet of robots to
map monitor and record the health of
corals around the
globe while reefs are under serious
threat all over there are some signs of
Hope and some surprising ideas for ways
to protect them including one that came
from this team's research
in their work they discovered that the
sound of a healthy Reef might actually
have an indirect healing effect on a
stressed Reef it has to do with the
coral animals life
cycle newly born baby corals tiny larv
drift in the ocean searching for
somewhere to settle it turns out the
sound of a thriving coral reef signals
them to settle into place once they find
a spot they can be very resilient and
grow for centuries so the the more larv
a reef can attract the healthier it will
be and that gave the team an idea we
know these reefs are degraded and we
want to rebuild them by attracting the
larve the Baby
Coral in a past experiment the team
found that larvey could be drawn to
recordings of healthy
reefs so by placing speakers in
strategic locations they could give a
boost where it's needed most and that
system actually leverages the healthy
soundscape and plays it back into the
environment and the idea is that it
induces Coral ly to kind choose that
environment and
settle the result up to seven times more
larvey settlement compared to a degraded
Reef without the audio boost a very
encouraging
sign but back to St John and cury the
team is ready for the final test of the
day the robot's going to use the
direction that it's finding from its hyr
phones and then drive itself to whatever
the nearest acoustic source is which
we're hoping is going to be Joel sh Reef
this time since c will pilot itself it's
tethered for safety they put curri in
the water and give it the green light
are we expecting it to be moving or not
we are it looks at first as though it's
orienting toward the sound of the reef
it thinks it's moving but after a few
minutes it's clear that curri isn't
making much Headway it's just dumb stuff
in the way that I wrote it seems there's
an issue with the
software all right bring it
back it's coming up I can now see it
they're starting to lose the light
dark they weren't able to check off
everything on the day's to-do list yet
they remain
upbeat we're all happy right now cuz uh
we ended the day with as many robots as
we started the day with
it's frustrating in the moment but
they're making
progress the creative act of
engineering has got
disappointment has got
failure and that's how we learn so it is
a big ball of of um two steps forward
and one step back when you have a a very
massive why and a very massive purpose
for what you're trying to do such as
save the core
it allows you to experience the
disappointment but not be defeated by it
and continue to try the process of
moving it
forward if you're not failing you're not
trying hard enough yeah it's very
frustrating but when it works it's very
satisfying engineering solutions to The
Climate crisis will require creativity
Innovation and a global commitment to
making smart choices