May 5, 2025 • 18 mins
Coral bleaching is not just a temporary event—it’s a climate emergency that can unfold over years. In this episode of How to Protect the Ocean, host Andrew Lewin dives deep into the devastating history of global coral bleaching events, revealing how the fourth and current one (2023–2025) is affecting over 80% of coral reefs worldwide. From the Great Barrier Reef to the Caribbean, bleaching is now a global phenomenon threatening biodiversity, food security, and coastal protection.
Climate change and rising ocean temperatures are causing corals to lose the vital algae that keep them alive. This episode unpacks the four global bleaching events (1998, 2010, 2014–2017, and now), explores why reefs are slow to recover, and explains what’s at stake for humans and marine ecosystems. You’ll also hear about the essential roles that coral reefs play—from acting as biodiversity hotspots to protecting coastlines during extreme weather events.
Link to article: https://www.theguardian.com/environment/2025/apr/23/coral-reef-bleaching-worst-global-event-on-record
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Transcript
Episode Transcript
Available transcripts are automatically generated. Complete accuracy is not guaranteed.
(00:00):
When somebody tells you that a coral reef
has bleached, what
goes through your mind?
Do you think that it only happens over a
couple of days, maybe
one day, maybe a couple of
weeks?
And then after that, the temperature goes
down and the coral recovers, right?
That's what you probably think.
Today we're going to be talking about
coral bleaching events
that happen over years.
There's going to be four that we're going
(00:21):
to be talking about.
We're going to go into a little bit of
detail in each one, but
we're currently in one since
2023 now to 2025.
We have seen 80% of coral reefs globally
that have bleached in this span.
It's not only in the Great Barrier Reef.
It's not only in Indonesia
or in the Southeast Pacific.
It's also in the Caribbean.
(00:41):
It's also in the Atlantic.
It's also in the Indian Ocean.
It's also everywhere.
It's pretty much
everywhere that we monitor reefs.
And this is something that we have to
talk about on today's episode of the how
to protect the ocean podcast.
Let's start the show.
Hey everybody, welcome back to another
exciting episode of the how
to protect the ocean podcast.
I'm your host, Andrew Lewin, and this is
(01:02):
the podcast where you find out what's
happening with the ocean,
(01:22):
and what's happening with the ocean.
And I'm going to show you the whole game of their series and be able to
eliminate the other senators.
But this is what
Canadians do when we do work.
We kind of look down every once in a
while to check the score to make sure
that the leaves are winning.
They're losing right now.
A little nervous.
That's okay.
We're going to get back into the episode.
Look, we're going to be talking about
coral reef bleaching
and not just over days.
I think what a lot of people think and
sort of I thought when I first heard of
(01:43):
coral reef bleaching because coral reefs
can recover after bleaching.
And we're going to go into what bleaching
is in just a second.
But I want you to understand the urgency
of the current bleaching crisis.
So we need to look at troubling history
of global bleaching events
over the past few decades.
There have been four major events.
Each one have been more
devastating than the last.
(02:04):
So the first one was in 1998 driven by a
powerful El Nino combined with rising
global temperatures, climate change.
It was the first time the world saw mass
coral death on a global scale.
So not just bleach, but
actual death on a global scale.
About 16% of the world's reef like across
the world were affected with the parts of
(02:26):
the Indian Ocean losing
up to 90% of their coral.
That is a huge amount.
Then came 2010.
So we had about 12 years in between
another intense El Nino like pattern hit
and it triggered a
global bleaching again.
Right.
Once again, while it wasn't as deadly as
1998, it served as a warning that these
events were no longer rare.
(02:46):
They were becoming more frequent.
So you think about 1998,
you have a major bleaching.
I remember people like I remember
politicians going, especially Ted Cruz
going on like a talk show, like a
celebrity talk show.
I think it was Letterman
or something like that.
And they were talking
about, you know, the quarries.
They were talking about bleaching and
they're talking about just temperature in
general at that time.
Climate denial was in full fledged like
(03:07):
the Republicans and conservatives here in
Canada were just denying everything.
Kyoto Protocol was not
even really a thing yet.
But people were talking about that as
like the Paris agreement of the 2000s.
But, you know, it was starting to be
talked about more and more because
scientists kept observing these bleaching
events and then also mass die
offs and temperature rising.
We started to see a pattern change more
(03:28):
and more and we're warning people.
I remember going, I was
getting school at this point.
I remember scientists and professors were
saying, we are in trouble
if we do not act in 1998.
In 1998, we were going to be
in trouble if we didn't act.
Look, we are now 2025.
We haven't acted as
fast as what we needed to.
But then, you know, you go 2010, you
think you're done, you think you're OK,
(03:49):
you think out of it
denialism is still hot and ready.
You know, people are just still denying.
The oil and gas companies are strong in
their PR and they
just continue to do that.
You get another bleach event.
Not as bad, but you get
another bleaching event.
But all this talk about denial, people
are like, yeah, well, you know what?
You know, we saw a peak in 1980 and then
it started to go down a bit.
So it's starting to decrease.
(04:10):
And you know what was happening is if you
just looked at from 1998 to 2010, yeah,
it didn't look like it was fluctuating
and looked like it was going
down because 1998 was so high.
But when you looked at the entire graph,
like for the last 100 or 200 years, you
can definitely see from the industrial
age, you started to see, whoo, it started
to go up and then it started to kind of
tail off a little bit, but still continue
(04:31):
to rise, which we know today continues to
rise, not as quickly, but it's still
rising and rising and rising.
And so we continue to get hotter and
hotter years and break
records every single year.
We're in a bleaching event.
But the third bleaching event happened
between 2014 and 2017.
This was the longest and most widespread
(04:51):
bleaching event on record at the time.
It struck hard across the Pacific, the
Indian and the Atlantic oceans.
The Great Barrier Reef in particular
suffered catastrophic losses.
Parts of it experienced back to back
bleaching with little time to recover.
So again, coral reefs can recover from
bleaching, but if it's too long, you
know, if it's one of those times where
(05:12):
it's like the temperature stays long,
like above 40 degrees Celsius for too
long in a row in too many days in a row,
we're talking about 40, 50 days, then
bleaching will continue and the coral
will eventually die because it can't get
the products it needs from
the algae that's in them.
Right. We'll talk about
that in just a second.
So from 2014 to 2017 was the third event.
(05:33):
That's three years. That's three years,
right? And you're sitting there, you're
like, hold on a second here. That was the
longest. Now we're in the midst of a
fourth global bleaching event.
And from 2023 and we're now today 2025.
So we don't know when this is ending.
It's not ending. It hasn't ended yet.
It's already the worst on record with
more than 80 percent. 80 percent of coral
(05:55):
reefs across 82 countries showing signs of a global bleaching event.
And that's why we're talking about the kinds of bleaching. What's especially
alarming is that even the most remote and
previously resilient areas like Raja and
pot and the Gulf of a lot have been hit
and are seeing death with their corals.
Right. So this isn't just a climate
story. This is a biodiversity story. This
(06:16):
is a food security story. This is a human
story. This is affecting people across 82
countries, maybe even more.
Each bleaching event chips away at
ecosystems that could take centuries to
build. And unless we change our course,
the next one may even come
sooner and hit harder for longer.
(06:37):
This is devastating to so many people
around the world that depend on reefs for
food and for security. Coral reefs are
biodiversity hotspots that they contain
about a third of the species
in the ocean that we know of.
There's probably a lot more, but they
contain a third of the species that we
know of. And so having coral reefs there
are very important in particular coral
(06:58):
reefs. So like what we call the reef
building coral reefs, right? The corals.
So the Staghorn, the branching corals,
the Montipora, which is the flat corals,
sort of the plate corals as they call
them, right? Those types of corals are
reef building. They build out those
reefs. They provide those hiding spots
that brings in the biodiversity of
invertebrates and
vertebrates like fish and so forth.
(07:18):
Inverbers like crab shrimp and that kind
of stuff that brings in all the big fish.
It brings in the sharks. It brings in
everything. It's this home that is a huge
biodiversity hotspot, but it also
provides security for the coastline. Back
in 2004 when we had the tsunami on
Christmas day, right? Christmas and
boxing day in the Indian Ocean.
(07:40):
They're affected Africa, affected South
Asia, and it affected a lot of the
islands in the Southeast Pacific. These
places were devastated in the places that
actually survived the best and did the
best from a coastal resilient point of
view had coral reefs that were intact,
had seagrass beds that were intact, had
mangroves that were intact.
(08:00):
Meaning that they were up and running and
they were healthy. A lot of places that
didn't have those coral systems or
seagrass systems or mangrove systems had
huge losses of not only people, but just
land because the water
just went right over it.
There was nothing to stop it. The coastal
security that coral reefs provide is
dissipation of energy from waves. That
(08:21):
means if a tsunami wave comes over, it's
got all this energy. It's got all this
momentum and it hits a coral reef.
All that coral reef with this branching
corals and all these different areas, it
provides resistance to the wave. So the
energy, the speed and the power
dissipates as it goes over the reef and
then it'll dissipate again as it go over
(08:43):
seagrass habitat and it'll dissipate
again as it goes over mangrove habitat,
especially when it starts to come on
land. These mangroves are thick.
If you've never tried to trek through a
mangrove area without those nice
boardwalks that sometimes people put
through, it's almost impossible. So when
a wave hits those, then it really
dissipates the energy and it breaks up
(09:04):
the waves and it's not as hard hit that
city or village or towns that are behind
there are not hardest hit.
So that's what happened in 2004. But now,
like even as bleaching events started to
happen and it continues to happen longer
and longer periods and getting worse and
worse. So in 2014 to 2017, 60% of the
(09:25):
corals around the world died. Now it's
80% not recovering guys. This is not
recovering very well.
And what's going to happen over time is
we're going to see a change in the makeup
of corals. So we're going to get less of
these hard corals, like the staghorn
corals, the branching
corals and the plate corals.
And we're going to start to see more soft
corals that maybe are a little bit more
(09:45):
heat resistant. So let's get into why
that's important to know. So when you
look at a coral reef, right, it has this
hard body a lot of the times or soft
body, depending if it's
hard coral or soft coral.
But it has this body has this like
skeleton and a lot of times like the hard
corals are like a limestone skeleton. And
over that skeleton, you have this fleshy
material, which is the coral and that
(10:07):
coral gets its food from this little tiny
microscopic organism called a zoo and LA.
It's basically an algae cell and many,
many algae cells within this body within
this kind of coral skeleton, if you will.
And that algae gets its energy from the
sun from photosynthesis. That's how it
(10:27):
feeds and the byproducts of that is like
calcium and other stuff. Right. And so
that calcium helps build the coral reefs.
It helps build the skeleton of that
course with the fleshiness can stand on
top and the food, it gets like the
byproducts, it gets and it actually
becomes a healthy coral. That's the
simplistic version of the coral.
And that's the simplistic version of how
a coral eats and how it becomes so
beautiful in the different colors and the
(10:48):
radiant colors. It's the algae inside
that reflect those colors, right? That's
what we're seeing. Now, if the water gets
too hot, those algae are like, I don't
like it in here. I'm out of here. And
they get expelled. Even the corals like,
no, you got to go. It's getting too hot.
I can't handle you in here. You got to
go. I got to start looking at my body and
starting to just contain it whatever I
(11:09):
can. So it expels the zoo
and LA into the water column.
As long as the temperature stays that
temperature, the corals like, no, I got
to get rid of everything. So it loses its
color. Eventually loses like the
fleshiness of the coral around it. All
the polyps, all those little polyps that
feed and then the coral can't sustain
itself. If the zoo, it like goes away for
(11:29):
too long, then it won't come back and the
coral dies because it has no way of
feeding. If the temperature goes down and
the zoo, I thought it comes back. These
little algae cells come back.
Then it can recover a little bit
depending on how badly it's gone or how long it's been bleached. That's why you get the white bleaching is when the zoo and they are out, you lose the color is white. It's bleached. But when it comes back, it can be healthy again. Now we have to even go further down is looking at the differenttypes of zoo and delay. Now the research that I've done a while ago is there's pretty much four different types. You got ABC and D will keep it as simplistic as possible. Now, certain zoo and delay will react at certain temperatures. That's why coral reefs, they're very important to the
(12:10):
sea. They're very sensitive to outside
changes. They don't like changes. If
you've ever had a marine or ocean like or
saltwater tank and you've had corals in
there, you realize how important it is to
keep the water at certain measurements,
temperature has to stay within a certain
range. PH has to stay within a certain
range. The light has to be there for it
and it can't be shaded by another rock or
(12:33):
another coral or even algae that grows on top. It's very specific. And any time those values go out, they can be
outside of that range. The coral is not
healthy. So if you get the temperature
that comes in and heats it up, then the
zoo and I get expelled and that happens.
So if it happens for over a long period
of time, you're not going to get that zoo
and deli back and you're going to get
(12:54):
death to the coral going back to the
different types of zoo and deli. They
have different heat signatures. So
different ranges of tolerance for heat.
So if you think about it, and I don't
know for sure. But if you think about a
as the lowest range, so it's very
specific. So if anything goes above or
outside of that range by going higher or
even lower, but in this case, it's going
(13:14):
higher than those who went there, they
were like, I'm out. We're gone. B is a
little higher tolerance. C is a little
higher tolerance and D is a little higher
tolerance, right? And D is what people
are looking at and really looking at what
corals will like because certain corals
like certain zoo and deli. They'll be
benefiting more of the coral depending on
the type of zoo and deli. So if you have
D that only like soft corals and the D
(13:36):
zoo and deli are going to be more heat
tolerant to a higher temperature,
then we're going to start to see more of
these soft corals that like the zoo and
deli that the type D zoo and deli around
in the coral reefs. So we're going to see
a change. But if the Staghorn like the
branching or the plate corals like are
there or the boulder corals like hard
corals that are boulders. If they like
the type A, which is the lowest range,
(13:58):
then a higher temperature range is not
going to be suitable for those types of
corals. So essentially what's going to
happen is we may not see the loss of
corals completely, but we're definitely
going to see a shift in the makeup.
Of what the coral reefs will look like
and that may affect what type of fish,
what type of invertebrates are on these
types of reefs, what protection it gives
(14:20):
because there's a real difference between
a soft coral and a hard coral. When you
think about hiding spots, a soft coral is
a little bit more permeable to moving
around a hard call it breaks. It's hard.
If you try to get in there, if you're
fish trying to get like a crab or shrimp,
it's very difficult to get in there. If
these corals are, you know, not
protecting or if these corals are soft,
it's easier to get in. I can move it
around with my fish.
(14:40):
I can move it around with my snout or I
can, you know, move it around with my
jaw, whatever you need to do. But if it's
hard, it's really difficult for some of
these fish to get in there without
getting cut or out getting damaged. So
having that shift could pose a lot of
problems and shift what we think coral
reefs look like in the future. And that's
where it becomes a problem. So if you
think about it, we may not lose corals
altogether, but we're going to lose the
(15:02):
corals that we know and love and then
provide the coral reef biodiversity as
well as security for our coastal systems,
which we need more and more
and more as climate change.
But change gets bigger. So what do we do?
Andrew, you're telling me a lot of
depressing stuff. What do we do? Look,
we've gone through the problem. We're
looking at the science, looking at the
biology and the ecology. Now, what do we
do? The biggest thing is we got to talk
(15:24):
to our government officials. We got to
say we need to lower down greenhouse
gases and we need to do better when we're
looking at this stuff, right? Because
coral reefs are affected because the
heat's rising because the greenhouse
gases are going up and it's because of a
lot of developed
countries or industrialized
countries who are providing that type of
pollution or it's providing that type of
(15:44):
greenhouse gas that's affecting the
global temperatures. We need to reduce
those. That's not a quick turnaround.
It's not a short term solution. We need
to do that as a long term solution, but
we got to stop voting in these people who
are in these governments that love to go
against the grain and start calling
climate changes a hoax. They don't know
anything about science. They're not
educated in science and they're not
(16:06):
practical and they're not looking at
renewable energies clean
and clean and they're not
going to be able to provide energy that
will not provide CO2 or methane gases in
the atmosphere. Everything else needs to
change. We need to change the way we
think we need to change the way we do
life, which is not easy, but we're
getting in trouble here, folks. We are in
trouble. We're seeing wildfires. We're
(16:26):
seeing droughts. We're seeing flooding.
We're seeing tsunamis. We're seeing
earthquakes. Volcanoes are increasing and
that could be linked to climate change,
which I'll cover in the next episode. We
are seeing some problems and it's not
going to go away. So we need to do
something about it. If you love coral reefs, we need to do something about it.
We need to reach the way they are. If you
are a diver, if you are a surfer, if you
just love the ocean and you want to see
(16:46):
more of these corals, we need to act by
speaking to your government
representatives as a community, as a
region, as a country, as a world
population. We cannot take these
governments that are in that are not
doing anything about climate change. In
fact, going backwards and making it
worse. That's what we have to do and it's
(17:08):
on us to make sure our governments do it.
We need to vote them in and if they're
not listening to us when they're voted
in, get them out the next time you vote.
I know it's a long period of time, but
you gotta get them out because we are in
peril. This is not a joke. This is not
exaggerating. These coral reefs, 80% of
them have died. Even the ones that are
(17:28):
remote that we actually thought, hey, a
few years ago, the ones that are remote
actually do okay because there's less
cumulative effects. I remember covering
them on stories. Nope, not anymore. It's
too much now. Too much, too
high, too long, temporary.
The temperature is just too much. So
that's what we have to do. That's the
call of action act. Speak to your
government representatives and that's the
(17:49):
episode for today. If you have any
questions or comments, leave them in the
comments below. If you're watching this
on YouTube, if you're listening to this
on audio podcast, which I love, because
this is the way I started and I just
continue to love it, please get ahold of
me either, go to speakupforblue.com, hit
the contact page, fill out the form that
goes right to my personal email or you
can go to Instagram. Hit me up on app,
(18:09):
how to protect the ocean. That's it.
That's it. I'm Andrew Lewis from the true
(18:32):
north strong and free. Have a great day.
We'll talk to you next
time and happy conservation.
When somebody tells you that a coral reef
has bleached, what
goes through your mind?
Do you think that it only happens over a
couple of days, maybe
one day, maybe a couple of
weeks?
And then after that, the temperature goes
down and the coral recovers, right?
That's what you probably think.
Today we're going to be talking about
coral bleaching events
that happen over years.
There's going to be four that we're going
(00:21):
to be talking about.
We're going to go into a little bit of
detail in each one, but
we're currently in one since
2023 now to 2025.
We have seen 80% of coral reefs globally
that have bleached in this span.
It's not only in the Great Barrier Reef.
It's not only in Indonesia
or in the Southeast Pacific.
It's also in the Caribbean.
(00:41):
It's also in the Atlantic.
It's also in the Indian Ocean.
It's also everywhere.
It's pretty much
everywhere that we monitor reefs.
And this is something that we have to
talk about on today's episode of the how
to protect the ocean podcast.
Let's start the show.
Hey everybody, welcome back to another
exciting episode of the how
to protect the ocean podcast.
I'm your host, Andrew Lewin, and this is
(01:02):
the podcast where you find out what's
happening with the ocean,
(01:22):
and what's happening with the ocean.
And I'm going to show you the whole game of their series and be able to
eliminate the other senators.
But this is what
Canadians do when we do work.
We kind of look down every once in a
while to check the score to make sure
that the leaves are winning.
They're losing right now.
A little nervous.
That's okay.
We're going to get back into the episode.
Look, we're going to be talking about
coral reef bleaching
and not just over days.
I think what a lot of people think and
sort of I thought when I first heard of
(01:43):
coral reef bleaching because coral reefs
can recover after bleaching.
And we're going to go into what bleaching
is in just a second.
But I want you to understand the urgency
of the current bleaching crisis.
So we need to look at troubling history
of global bleaching events
over the past few decades.
There have been four major events.
Each one have been more
devastating than the last.
(02:04):
So the first one was in 1998 driven by a
powerful El Nino combined with rising
global temperatures, climate change.
It was the first time the world saw mass
coral death on a global scale.
So not just bleach, but
actual death on a global scale.
About 16% of the world's reef like across
the world were affected with the parts of
(02:26):
the Indian Ocean losing
up to 90% of their coral.
That is a huge amount.
Then came 2010.
So we had about 12 years in between
another intense El Nino like pattern hit
and it triggered a
global bleaching again.
Right.
Once again, while it wasn't as deadly as
1998, it served as a warning that these
events were no longer rare.
(02:46):
They were becoming more frequent.
So you think about 1998,
you have a major bleaching.
I remember people like I remember
politicians going, especially Ted Cruz
going on like a talk show, like a
celebrity talk show.
I think it was Letterman
or something like that.
And they were talking
about, you know, the quarries.
They were talking about bleaching and
they're talking about just temperature in
general at that time.
Climate denial was in full fledged like
(03:07):
the Republicans and conservatives here in
Canada were just denying everything.
Kyoto Protocol was not
even really a thing yet.
But people were talking about that as
like the Paris agreement of the 2000s.
But, you know, it was starting to be
talked about more and more because
scientists kept observing these bleaching
events and then also mass die
offs and temperature rising.
We started to see a pattern change more
(03:28):
and more and we're warning people.
I remember going, I was
getting school at this point.
I remember scientists and professors were
saying, we are in trouble
if we do not act in 1998.
In 1998, we were going to be
in trouble if we didn't act.
Look, we are now 2025.
We haven't acted as
fast as what we needed to.
But then, you know, you go 2010, you
think you're done, you think you're OK,
(03:49):
you think out of it
denialism is still hot and ready.
You know, people are just still denying.
The oil and gas companies are strong in
their PR and they
just continue to do that.
You get another bleach event.
Not as bad, but you get
another bleaching event.
But all this talk about denial, people
are like, yeah, well, you know what?
You know, we saw a peak in 1980 and then
it started to go down a bit.
So it's starting to decrease.
(04:10):
And you know what was happening is if you
just looked at from 1998 to 2010, yeah,
it didn't look like it was fluctuating
and looked like it was going
down because 1998 was so high.
But when you looked at the entire graph,
like for the last 100 or 200 years, you
can definitely see from the industrial
age, you started to see, whoo, it started
to go up and then it started to kind of
tail off a little bit, but still continue
(04:31):
to rise, which we know today continues to
rise, not as quickly, but it's still
rising and rising and rising.
And so we continue to get hotter and
hotter years and break
records every single year.
We're in a bleaching event.
But the third bleaching event happened
between 2014 and 2017.
This was the longest and most widespread
(04:51):
bleaching event on record at the time.
It struck hard across the Pacific, the
Indian and the Atlantic oceans.
The Great Barrier Reef in particular
suffered catastrophic losses.
Parts of it experienced back to back
bleaching with little time to recover.
So again, coral reefs can recover from
bleaching, but if it's too long, you
know, if it's one of those times where
(05:12):
it's like the temperature stays long,
like above 40 degrees Celsius for too
long in a row in too many days in a row,
we're talking about 40, 50 days, then
bleaching will continue and the coral
will eventually die because it can't get
the products it needs from
the algae that's in them.
Right. We'll talk about
that in just a second.
So from 2014 to 2017 was the third event.
(05:33):
That's three years. That's three years,
right? And you're sitting there, you're
like, hold on a second here. That was the
longest. Now we're in the midst of a
fourth global bleaching event.
And from 2023 and we're now today 2025.
So we don't know when this is ending.
It's not ending. It hasn't ended yet.
It's already the worst on record with
more than 80 percent. 80 percent of coral
(05:55):
reefs across 82 countries showing signs of a global bleaching event.
And that's why we're talking about the kinds of bleaching. What's especially
alarming is that even the most remote and
previously resilient areas like Raja and
pot and the Gulf of a lot have been hit
and are seeing death with their corals.
Right. So this isn't just a climate
story. This is a biodiversity story. This
(06:16):
is a food security story. This is a human
story. This is affecting people across 82
countries, maybe even more.
Each bleaching event chips away at
ecosystems that could take centuries to
build. And unless we change our course,
the next one may even come
sooner and hit harder for longer.
(06:37):
This is devastating to so many people
around the world that depend on reefs for
food and for security. Coral reefs are
biodiversity hotspots that they contain
about a third of the species
in the ocean that we know of.
There's probably a lot more, but they
contain a third of the species that we
know of. And so having coral reefs there
are very important in particular coral
(06:58):
reefs. So like what we call the reef
building coral reefs, right? The corals.
So the Staghorn, the branching corals,
the Montipora, which is the flat corals,
sort of the plate corals as they call
them, right? Those types of corals are
reef building. They build out those
reefs. They provide those hiding spots
that brings in the biodiversity of
invertebrates and
vertebrates like fish and so forth.
(07:18):
Inverbers like crab shrimp and that kind
of stuff that brings in all the big fish.
It brings in the sharks. It brings in
everything. It's this home that is a huge
biodiversity hotspot, but it also
provides security for the coastline. Back
in 2004 when we had the tsunami on
Christmas day, right? Christmas and
boxing day in the Indian Ocean.
(07:40):
They're affected Africa, affected South
Asia, and it affected a lot of the
islands in the Southeast Pacific. These
places were devastated in the places that
actually survived the best and did the
best from a coastal resilient point of
view had coral reefs that were intact,
had seagrass beds that were intact, had
mangroves that were intact.
(08:00):
Meaning that they were up and running and
they were healthy. A lot of places that
didn't have those coral systems or
seagrass systems or mangrove systems had
huge losses of not only people, but just
land because the water
just went right over it.
There was nothing to stop it. The coastal
security that coral reefs provide is
dissipation of energy from waves. That
(08:21):
means if a tsunami wave comes over, it's
got all this energy. It's got all this
momentum and it hits a coral reef.
All that coral reef with this branching
corals and all these different areas, it
provides resistance to the wave. So the
energy, the speed and the power
dissipates as it goes over the reef and
then it'll dissipate again as it go over
(08:43):
seagrass habitat and it'll dissipate
again as it goes over mangrove habitat,
especially when it starts to come on
land. These mangroves are thick.
If you've never tried to trek through a
mangrove area without those nice
boardwalks that sometimes people put
through, it's almost impossible. So when
a wave hits those, then it really
dissipates the energy and it breaks up
(09:04):
the waves and it's not as hard hit that
city or village or towns that are behind
there are not hardest hit.
So that's what happened in 2004. But now,
like even as bleaching events started to
happen and it continues to happen longer
and longer periods and getting worse and
worse. So in 2014 to 2017, 60% of the
(09:25):
corals around the world died. Now it's
80% not recovering guys. This is not
recovering very well.
And what's going to happen over time is
we're going to see a change in the makeup
of corals. So we're going to get less of
these hard corals, like the staghorn
corals, the branching
corals and the plate corals.
And we're going to start to see more soft
corals that maybe are a little bit more
(09:45):
heat resistant. So let's get into why
that's important to know. So when you
look at a coral reef, right, it has this
hard body a lot of the times or soft
body, depending if it's
hard coral or soft coral.
But it has this body has this like
skeleton and a lot of times like the hard
corals are like a limestone skeleton. And
over that skeleton, you have this fleshy
material, which is the coral and that
(10:07):
coral gets its food from this little tiny
microscopic organism called a zoo and LA.
It's basically an algae cell and many,
many algae cells within this body within
this kind of coral skeleton, if you will.
And that algae gets its energy from the
sun from photosynthesis. That's how it
(10:27):
feeds and the byproducts of that is like
calcium and other stuff. Right. And so
that calcium helps build the coral reefs.
It helps build the skeleton of that
course with the fleshiness can stand on
top and the food, it gets like the
byproducts, it gets and it actually
becomes a healthy coral. That's the
simplistic version of the coral.
And that's the simplistic version of how
a coral eats and how it becomes so
beautiful in the different colors and the
(10:48):
radiant colors. It's the algae inside
that reflect those colors, right? That's
what we're seeing. Now, if the water gets
too hot, those algae are like, I don't
like it in here. I'm out of here. And
they get expelled. Even the corals like,
no, you got to go. It's getting too hot.
I can't handle you in here. You got to
go. I got to start looking at my body and
starting to just contain it whatever I
(11:09):
can. So it expels the zoo
and LA into the water column.
As long as the temperature stays that
temperature, the corals like, no, I got
to get rid of everything. So it loses its
color. Eventually loses like the
fleshiness of the coral around it. All
the polyps, all those little polyps that
feed and then the coral can't sustain
itself. If the zoo, it like goes away for
(11:29):
too long, then it won't come back and the
coral dies because it has no way of
feeding. If the temperature goes down and
the zoo, I thought it comes back. These
little algae cells come back.
Then it can recover a little bit
depending on how badly it's gone or how long it's been bleached. That's why you get the white bleaching is when the zoo and they are out, you lose the color is white. It's bleached. But when it comes back, it can be healthy again. Now we have to even go further down is looking at the differenttypes of zoo and delay. Now the research that I've done a while ago is there's pretty much four different types. You got ABC and D will keep it as simplistic as possible. Now, certain zoo and delay will react at certain temperatures. That's why coral reefs, they're very important to the
(12:10):
sea. They're very sensitive to outside
changes. They don't like changes. If
you've ever had a marine or ocean like or
saltwater tank and you've had corals in
there, you realize how important it is to
keep the water at certain measurements,
temperature has to stay within a certain
range. PH has to stay within a certain
range. The light has to be there for it
and it can't be shaded by another rock or
(12:33):
another coral or even algae that grows on top. It's very specific. And any time those values go out, they can be
outside of that range. The coral is not
healthy. So if you get the temperature
that comes in and heats it up, then the
zoo and I get expelled and that happens.
So if it happens for over a long period
of time, you're not going to get that zoo
and deli back and you're going to get
(12:54):
death to the coral going back to the
different types of zoo and deli. They
have different heat signatures. So
different ranges of tolerance for heat.
So if you think about it, and I don't
know for sure. But if you think about a
as the lowest range, so it's very
specific. So if anything goes above or
outside of that range by going higher or
even lower, but in this case, it's going
(13:14):
higher than those who went there, they
were like, I'm out. We're gone. B is a
little higher tolerance. C is a little
higher tolerance and D is a little higher
tolerance, right? And D is what people
are looking at and really looking at what
corals will like because certain corals
like certain zoo and deli. They'll be
benefiting more of the coral depending on
the type of zoo and deli. So if you have
D that only like soft corals and the D
(13:36):
zoo and deli are going to be more heat
tolerant to a higher temperature,
then we're going to start to see more of
these soft corals that like the zoo and
deli that the type D zoo and deli around
in the coral reefs. So we're going to see
a change. But if the Staghorn like the
branching or the plate corals like are
there or the boulder corals like hard
corals that are boulders. If they like
the type A, which is the lowest range,
(13:58):
then a higher temperature range is not
going to be suitable for those types of
corals. So essentially what's going to
happen is we may not see the loss of
corals completely, but we're definitely
going to see a shift in the makeup.
Of what the coral reefs will look like
and that may affect what type of fish,
what type of invertebrates are on these
types of reefs, what protection it gives
(14:20):
because there's a real difference between
a soft coral and a hard coral. When you
think about hiding spots, a soft coral is
a little bit more permeable to moving
around a hard call it breaks. It's hard.
If you try to get in there, if you're
fish trying to get like a crab or shrimp,
it's very difficult to get in there. If
these corals are, you know, not
protecting or if these corals are soft,
it's easier to get in. I can move it
around with my fish.
(14:40):
I can move it around with my snout or I
can, you know, move it around with my
jaw, whatever you need to do. But if it's
hard, it's really difficult for some of
these fish to get in there without
getting cut or out getting damaged. So
having that shift could pose a lot of
problems and shift what we think coral
reefs look like in the future. And that's
where it becomes a problem. So if you
think about it, we may not lose corals
altogether, but we're going to lose the
(15:02):
corals that we know and love and then
provide the coral reef biodiversity as
well as security for our coastal systems,
which we need more and more
and more as climate change.
But change gets bigger. So what do we do?
Andrew, you're telling me a lot of
depressing stuff. What do we do? Look,
we've gone through the problem. We're
looking at the science, looking at the
biology and the ecology. Now, what do we
do? The biggest thing is we got to talk
(15:24):
to our government officials. We got to
say we need to lower down greenhouse
gases and we need to do better when we're
looking at this stuff, right? Because
coral reefs are affected because the
heat's rising because the greenhouse
gases are going up and it's because of a
lot of developed
countries or industrialized
countries who are providing that type of
pollution or it's providing that type of
(15:44):
greenhouse gas that's affecting the
global temperatures. We need to reduce
those. That's not a quick turnaround.
It's not a short term solution. We need
to do that as a long term solution, but
we got to stop voting in these people who
are in these governments that love to go
against the grain and start calling
climate changes a hoax. They don't know
anything about science. They're not
educated in science and they're not
(16:06):
practical and they're not looking at
renewable energies clean
and clean and they're not
going to be able to provide energy that
will not provide CO2 or methane gases in
the atmosphere. Everything else needs to
change. We need to change the way we
think we need to change the way we do
life, which is not easy, but we're
getting in trouble here, folks. We are in
trouble. We're seeing wildfires. We're
(16:26):
seeing droughts. We're seeing flooding.
We're seeing tsunamis. We're seeing
earthquakes. Volcanoes are increasing and
that could be linked to climate change,
which I'll cover in the next episode. We
are seeing some problems and it's not
going to go away. So we need to do
something about it. If you love coral reefs, we need to do something about it.
We need to reach the way they are. If you
are a diver, if you are a surfer, if you
just love the ocean and you want to see
(16:46):
more of these corals, we need to act by
speaking to your government
representatives as a community, as a
region, as a country, as a world
population. We cannot take these
governments that are in that are not
doing anything about climate change. In
fact, going backwards and making it
worse. That's what we have to do and it's
(17:08):
on us to make sure our governments do it.
We need to vote them in and if they're
not listening to us when they're voted
in, get them out the next time you vote.
I know it's a long period of time, but
you gotta get them out because we are in
peril. This is not a joke. This is not
exaggerating. These coral reefs, 80% of
them have died. Even the ones that are
(17:28):
remote that we actually thought, hey, a
few years ago, the ones that are remote
actually do okay because there's less
cumulative effects. I remember covering
them on stories. Nope, not anymore. It's
too much now. Too much, too
high, too long, temporary.
The temperature is just too much. So
that's what we have to do. That's the
call of action act. Speak to your
government representatives and that's the
(17:49):
episode for today. If you have any
questions or comments, leave them in the
comments below. If you're watching this
on YouTube, if you're listening to this
on audio podcast, which I love, because
this is the way I started and I just
continue to love it, please get ahold of
me either, go to speakupforblue.com, hit
the contact page, fill out the form that
goes right to my personal email or you
can go to Instagram. Hit me up on app,
(18:09):
how to protect the ocean. That's it.
That's it. I'm Andrew Lewis from the true
(18:32):
north strong and free. Have a great day.
We'll talk to you next
time and happy conservation.
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