TED2017
Kristen Marhaver: Why I still have hope for coral reefs
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Corals in the Pacific Ocean have been dying at an alarming rate, particularly from bleaching brought on by increased water temperatures. But it's not too late to act, says TED Fellow Kristen Marhaver. She points to the Caribbean -- given time, stable temperatures and strong protection, corals there have shown the ability to survive and recover from trauma. Marhaver reminds us why we need to keep working to protect the precious corals we have left. "Corals have always been playing the long game," she says, "and now so are we."
Kristen Marhaver - Coral reef biologist
TED Senior Fellow Kristen Marhaver is a marine biologist studying the ecology, behavior and reproduction of reef corals. Full bio
TED Senior Fellow Kristen Marhaver is a marine biologist studying the ecology, behavior and reproduction of reef corals. Full bio
Double-click the English transcript below to play the video.
00:12
The first time I cried underwater
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was in 2008,
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the island of Curaçao,
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way down in the southern Caribbean.
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It's beautiful there.
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I was studying these corals for my PhD,
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and after days and days
of diving on the same reef,
of diving on the same reef,
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I had gotten to know them as individuals.
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I had made friends with coral colonies --
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totally a normal thing to do.
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Then, Hurricane Omar smashed them apart
and ripped off their skin,
and ripped off their skin,
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leaving little bits of wounded tissue
that would have a hard time healing,
that would have a hard time healing,
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and big patches of dead skeleton
that would get overgrown by algae.
that would get overgrown by algae.
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When I saw this damage for the first time,
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stretching all the way down the reef,
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I sunk onto the sand in my scuba gear
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and I cried.
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If a coral could die that fast,
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how could a reef ever survive?
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And why was I making it my job
to try to fight for them?
to try to fight for them?
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I never heard another scientist
tell that kind of story
tell that kind of story
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until last year.
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A scientist in Guam wrote,
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"I cried right into my mask,"
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seeing the damage on the reefs.
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Then a scientist in Australia wrote,
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"I showed my students
the results of our coral surveys,
the results of our coral surveys,
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and we wept."
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Crying about corals
is having a moment, guys.
is having a moment, guys.
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(Laughter)
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And that's because reefs in the Pacific
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are losing corals faster
than we've ever seen before.
than we've ever seen before.
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Because of climate change,
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the water is so hot for so long
in the summers,
in the summers,
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that these animals
can't function normally.
can't function normally.
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They're spitting out the colored algae
that lives in their skin,
that lives in their skin,
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and the clear bleached tissue
that's left usually starves to death
that's left usually starves to death
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and then rots away.
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Then the skeletons are overgrown by algae.
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This is happening
over an unbelievable scale.
over an unbelievable scale.
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The Northern Great Barrier Reef
lost two-thirds of its corals last year
lost two-thirds of its corals last year
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over a distance of hundreds of miles,
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then bleached again this year,
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and the bleaching stretched further south.
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Reefs in the Pacific
are in a nosedive right now,
are in a nosedive right now,
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and no one knows
how bad it's going to get,
how bad it's going to get,
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except ...
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over in the Caribbean where I work,
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we've already been through the nosedive.
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Reefs there have suffered
through centuries of intense human abuse.
through centuries of intense human abuse.
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We kind of already know
how the story goes.
how the story goes.
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And we might be able to help predict
what happens next.
what happens next.
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Let's consult a graph.
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Since the invention of scuba,
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scientists have measured
the amount of coral on the seafloor,
the amount of coral on the seafloor,
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and how it's changed through time.
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And after centuries
of ratcheting human pressure,
of ratcheting human pressure,
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Caribbean reefs met one of three fates.
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Some reefs lost their corals very quickly.
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Some reefs lost their corals more slowly,
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but kind of ended up in the same place.
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OK, so far this is not going very well.
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But some reefs in the Caribbean --
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the ones best protected
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and the ones a little
further from humans --
further from humans --
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they managed to hold onto their corals.
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Give us a challenge.
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And, we almost never saw a reef hit zero.
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The second time I cried underwater
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was on the north shore of Curaçao, 2011.
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It was the calmest day of the year,
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but it's always pretty
sketchy diving there.
sketchy diving there.
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My boyfriend and I swam against the waves.
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I watched my compass
so we could find our way back out,
so we could find our way back out,
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and he watched for sharks,
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and after 20 minutes of swimming
that felt like an hour,
that felt like an hour,
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we finally dropped down to the reef,
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and I was so shocked,
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and I was so happy
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that my eyes filled with tears.
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There were corals 1,000 years old
lined up one after another.
lined up one after another.
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They had survived the entire history
of European colonialism in the Caribbean,
of European colonialism in the Caribbean,
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and for centuries before that.
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I never knew what a coral could do
when it was given a chance to thrive.
when it was given a chance to thrive.
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The truth is that even
as we lose so many corals,
as we lose so many corals,
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even as we go through
this massive coral die-off,
this massive coral die-off,
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some reefs will survive.
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Some will be ragged on the edge,
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some will be beautiful.
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And by protecting shorelines
and giving us food to eat
and giving us food to eat
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and supporting tourism,
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they will still be worth
billions and billions of dollars a year.
billions and billions of dollars a year.
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The best time to protect a reef
was 50 years ago,
was 50 years ago,
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but the second-best time is right now.
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Even as we go through bleaching events,
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more frequent and in more places,
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some corals will be able to recover.
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We had a bleaching event
in 2010 in the Caribbean
in 2010 in the Caribbean
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that took off big patches of skin
on boulder corals like these.
on boulder corals like these.
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This coral lost half of its skin.
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But if you look at the side
of this coral a few years later,
of this coral a few years later,
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this coral is actually healthy again.
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It's doing what a healthy coral does.
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It's making copies of its polyps,
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it's fighting back the algae
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and it's reclaiming its territory.
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If a few polyps survive,
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a coral can regrow;
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it just needs time and protection
and a reasonable temperature.
and a reasonable temperature.
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Some corals can regrow in 10 years --
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others take a lot longer.
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But the more stresses
we take off them locally --
we take off them locally --
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things like overfishing,
sewage pollution, fertilizer pollution,
sewage pollution, fertilizer pollution,
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dredging, coastal construction --
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the better they can hang on
as we stabilize the climate,
as we stabilize the climate,
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and the faster they can regrow.
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And as we go through the long,
tough and necessary process
tough and necessary process
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of stabilizing the climate
of planet Earth,
of planet Earth,
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some new corals will still be born.
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This is what I study in my research.
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We try to understand
how corals make babies,
how corals make babies,
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and how those babies
find their way to the reef,
find their way to the reef,
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and we invent new methods
to help them survive
to help them survive
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those early, fragile life stages.
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One of my favorite
coral babies of all time
coral babies of all time
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showed up right after Hurricane Omar.
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It's the same species
I was studying before the storm,
I was studying before the storm,
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but you almost never see
babies of this species --
babies of this species --
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it's really rare.
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This is actually an endangered species.
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In this photo, this little baby coral,
this little circle of polyps,
this little circle of polyps,
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is a few years old.
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Like its cousins that bleach,
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it's fighting back the algae.
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And like its cousins on the north shore,
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it's aiming to live for 1,000 years.
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What's happening in the world
and in the ocean
and in the ocean
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has changed our time horizon.
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We can be incredibly pessimistic
on the short term,
on the short term,
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and mourn what we lost
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and what we really took for granted.
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But we can still be optimistic
on the long term,
on the long term,
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and we can still be ambitious
about what we fight for
about what we fight for
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and what we expect from our governments,
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from our planet.
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Corals have been living on planet Earth
for hundreds of millions of years.
for hundreds of millions of years.
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They survived the extinction
of the dinosaurs.
of the dinosaurs.
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They're badasses.
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(Laughter)
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An individual coral can go through
tremendous trauma and fully recover
tremendous trauma and fully recover
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if it's given a chance
and it's given protection.
and it's given protection.
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Corals have always
been playing the long game,
been playing the long game,
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and now so are we.
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Thanks very much.
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(Applause)
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ABOUT THE SPEAKER
Kristen Marhaver - Coral reef biologistTED Senior Fellow Kristen Marhaver is a marine biologist studying the ecology, behavior and reproduction of reef corals.
Why you should listen
Dr. Kristen Marhaver's work combines classic scientific methods with new technologies to help threatened coral species survive their early life stages. She was the first person to rear juveniles of the endangered Caribbean Pillar Coral. Now she's now developing bacterial tools to improve coral survival at all life stages.
Marhaver's research has been covered by NPR, BBC, The Atlantic and Popular Science, among hundreds of outlets. She's earned five fellowships and grants from the US National Science Foundation and multiple awards for science communication. Marhaver is a TED Senior Fellow, a WINGS Fellow, and a World Economic Forum Young Scientist.
Outside the lab, Marhaver advocates for stronger ocean conservation and smarter science communication. Her talks and articles have been featured by Google, Wired UK, Mission Blue and by ocean and scuba festivals around the world.
A scuba diver from the age of 15, Marhaver is a graduate of Georgia Institute of Technology and the Center for Marine Biodiversity and Conservation at Scripps Institution of Oceanography. Her lab is based at the CARMABI Research Station on the island of Curaçao.
Kristen Marhaver | Speaker | TED.com