-: Good evening, everyone.
We're pleased to have you join us
for our annual Seaside Chats speaker series
about ocean topics associated with Flower Garden Banks
National Marine Sanctuary and the Gulf of Mexico.
This year, we are also part
of the National Marine Sanctuaries Webinar Series,
which is hosted by NOAA's Office
of National Marine Sanctuaries.
And we are also part of the NOAA Science Seminar Series.
During the presentation, all attendees
will be in listen-only mode.
You are welcome to type questions for the presenter
into the question box at the bottom of the control panel
on the right-hand side of your screen.
This is the same area you can let us know
about any technical issues you may be having.
We will be monitoring incoming questions
and technical issues, and we'll respond to them
as soon as we can.
We are recording this session and we'll post the recording
to the National Marine Sanctuaries
and Flower Garden Banks National Marine Sanctuary websites.
We will notify registered participants via email
when these recordings are available.
And for those of you who are educators,
we have provided a Coral Spawning Globe activity,
a Splitting Coral Polyp diagram,
and a Predator-Prey Interactions in the Ocean activity
in the handouts pane of the control panel.
Simply click on these items to download them.
The Seaside Chats speaker series began as a way
for Flower Garden Banks National Marine Sanctuary
to share current research and management efforts
in the Gulf of Mexico in an informal setting.
These chats started in 2012 with presentations
in the gift shop of the Galveston Fishing Pier.
From one year to the next, we moved around
the Galveston community, hosting presentations
at Moody Gardens, Texas A&M Galveston,
Texas Seaport Museum, and Sea Star Base Galveston.
In 2020, we brought the presentations home to our offices
at historic Fort Crockett just before the world shut down
for the pandemic.
And although we have offered webinar connections
during our live events for many years, it wasn't until 2021
that we went completely virtual and joined forces
with the National Marine Sanctuaries webinar series.
In all that time, our Seaside Chats only missed one year,
2019, which makes this our 10th year of presentations.
We've chosen to recognize this milestone
with a brand new graphic that you see here.
We hope you agree with us that this comfortable chair
by the sea at sunset captures the essence of our program.
Hello, everyone, my name is Kelly Drinnen,
and I'm the education and outreach specialist
for Flower Garden Banks National Marine Sanctuary.
I'll be facilitating today's webinar from Dickinson, Texas.
Also with me today is Leslie Whaylen Clift,
our constituency affairs coordinator,
and Leslie will be helping me with back end administration
of this webinar.
50 years ago, the United States ushered in a new era
of ocean conservation by creating
the National Marine Sanctuary system.
Since then, we've grown into a nationwide network
of 15 National Marine Sanctuaries
and two Marine National Monuments
that conserve more than 620,000 square miles
of spectacular ocean and Great Lakes waters.
That's an area nearly the size of Alaska.
These marine protected areas
are somewhat like national parks
and national forests, but underwater.
In celebration of this 50th anniversary,
we are running a Save Spectacular campaign
across the entire sanctuary system, a way to remind everyone
just how special these places really are.
The National Marine Sanctuaries Act gives NOAA the authority
to designate special areas of the marine environment
as National Marine Sanctuaries.
It also mandates that the Office
of National Marine Sanctuaries conduct research, monitoring,
resource protection, education, outreach,
and management of America's underwater treasures
to preserve them for future generations.
In addition to being places for recreation and research,
National Marine Sanctuaries are also living classrooms
where people can see, touch, and learn
about the nation's Great Lakes and ocean treasures.
This webinar series is just one part
of that national education and outreach effort.
Today's Seaside Chat series is hosted
by Flower Garden Banks National Marine Sanctuary,
the only National Marine Sanctuary in the Gulf of Mexico.
This sanctuary consists of 17 banks,
or small underwater mountains, that are home
to some of the healthiest coral reefs in the world,
amazing algal and sponge communities, and deep reef habitats
featuring an abundance of black corals.
The original sanctuary designation took place in January
of 1992, so just a few weeks ago,
we celebrated our 30th anniversary.
As you can see, 2022 is turning out
to be quite the anniversary year.
Today's presentation focuses
on the Sex Lives of Corals, which exhibit some
of the most fascinating reproductive behavior
in the animal kingdom.
Once a year, they release their eggs and sperm
into the water column for external fertilization,
a strategy that enables corals,
which are usually stuck in one place,
to disperse to new reefs.
This spawning behavior also allows coral researchers
to study a variety of different topics
to better understand coral symbiosis, dispersal,
and responses to climate change.
Our speaker today will share some
of the exciting research her lab is doing,
including some of the ways this research
might inform coral conservation.
Today, we welcome Dr. Sarah Davies,
assistant professor of biology at Boston University,
to talk about her work with corals.
Sarah earned her Masters of Science
from the University of Calgary in 2009
and her PhD from the University of Texas at Austin in 2014.
In 2014, she worked as a post-doctoral researcher
at the University of North Carolina, and in 2016,
she became a Simon's Foundation Fellow
of the Life Sciences Research Foundation.
Sarah is an integrative biologist
and her expertise includes ecological genomics,
population genetics, physiology, and marine biology.
Her research largely focuses on how corals respond
to climate change.
She's also deeply passionate about mentorship
and its ability to facilitate increased representation
of marginalized scholars in STEM learning,
which is science, technology, engineering, and math.
Sarah has worked at the Flower Garden Banks since 2007,
and although she has spent time on many reefs
around the world, the annual coral spawning event
at Flower Garden Banks remains one
of her field work highlights to this date.
Welcome, Sarah.
-: Thanks, Kelly.
I'm gonna share.
All right.
So thanks for- -: Let's go, I can-
-: Can you hear me?
-: Yes, I can.
-: Cool.
-: And we're prepared to show your screen.
-: All right.
Okay, so sharing, okay, so first off,
thanks so much for the invite today.
-: Sarah, it's not quite, it's not in full screen,
there we go, now it's full screen.
-: Okay I think there's a little bit of a lag,
so I'll apologize in advance.
But yeah, so Kelly, thanks so much
for the invite to talk to everyone tonight.
You know, I think COVID has taught us that virtual learning
is really effective, so hopefully,
I can teach you something about the sex lives of corals,
thinking about coral spawning and coral conservation.
For any of you out there interested in following me
on Twitter, I share a lot of our lab's research
and talk a lot about mentorship and being a mom,
so if you're interested in any of those things,
feel free to give me a follow on Twitter.
So yeah, I'm an assistant professor at Boston University
and we work a lot on Flower Garden Banks coral,
so I'm excited to talk to you about that tonight.
So I have three sections of the talk.
The first is kind of like a Coral 101,
so we're gonna talk about corals, are they animals,
rocks, or plants, and talk about how they're in peril.
The second part of the talk
is gonna talk about their very intriguing sex life.
And the third part is thinking about more of my research,
from coral spawning to coral conservation.
All right, so we'll start here, so corals.
Whenever I talk to people about corals,
they're always like, have opinions about,
whether they're animals, rocks, or plants.
And the answer is they're all three and you're not wrong
if you think they're an animal or a rock or a plant,
but if you think they're all three, then you win a prize.
And that prize is just that you get a high five.
But corals are animals, so this is a picture I took
of a coral in Micronesia in 2010,
so when I was a budding marine biologist.
And this is a branching coral, quite beautiful.
And if you zoomed in on this,
you would see what coral nerds call polyps.
So this is a single coral polyp, this individual here,
so these are two polyps, and they're genetically identical.
So all of the polyps on this coral reproduce asexually
to make these colonies. But these are animals,
they look kind of like anemones, and that's because
I'll tell you in a second they're related.
So when we think about the tree of metazoan life
or animal life, we have everything
from sponges all the way up to humans.
And corals are here, so corals are in the phylum Cnidaria.
So they are related to jellyfish and anemones,
so like Finding Nemo's home.
So here is the coral, and they're distantly related to us
and these lovely women here who won the Nobel Prize.
So corals are most definitely animals,
but they're also most definitely rocks.
So when you look at this, if you were to touch it
on the reef, which you shouldn't
because it would hurt the coral,
but you would feel that it is rough and feels like a rock.
And that is because if you zoomed in
and took off the coral layer, you would see
these beautiful structures of calcium carbonate.
And this is the structure that the corals actually accrete.
And when they grow, they accrete on top of,
I'll show you in a second but,
and this is this beautiful lattice structure
that's made of calcium carbonate.
And when you take a cross-section,
so now this is a cross-section of a coral polyp,
and one interesting fact about the coral here
is that its mouth is also its butt.
So they only have one opening here to the outside world.
And here, we have the polyp and it's integrating here in
with the calcium carbonate skeleton,
and this is where the coral will accrete
that calcium carbonate skeleton.
So the coral literally builds this structure itself,
so this animal literally builds this beautiful structure,
and these structures have fascinated biologists forever,
you know, finding little pieces of coral on the beach,
they come in these beautiful variety of forms.
And when we think about it on a reef scale,
you have all of these beautiful shapes made
by all of these different species to produce coral reefs.
So they're most definitely rocks.
But they're also plants, or actually algae, to be specific.
So if we zoom in here, now we're looking
at a single polyp again.
But if you look at this, this polyp has this coloration.
And these are single-celled algae
in the family Symbiodiniaceae.
Don't try to spell it, it's a new word in our world
that's quite challenging.
But all of these little brown smudges are algal symbionts.
And these algal symbionts actually live inside the coral
in a vesicle called the symbiosome, so it's intracellular.
And so this is a brain coral now, but if we look in,
now we're looking down at the coral's mouth.
And this yellow and green part here is,
we're looking in a fluorescent microscope.
So the yellow and green are innate fluorescence
that the coral actually makes itself.
And then every single red dot you see
is a single algal cell.
So the algal cells are fluorescing in the red color here
because of chlorophyll fluorescence.
So this is what algae look like in culture.
So they're pretty cute, but maybe not as charismatic
as the corals, but when we think about
the symbiotic relationship, the majority of tropical corals,
this relationship is actually mandatory or obligate.
So when we think about what the corals get
from the symbionts, well, just like trees,
the algae will photosynthesize
and they give the coral, 'cause they're intracellular,
they give them their carbon sugars.
So it's a byproduct of photosynthesis,
the algae doesn't need it.
And in return, the coral will actually give the algae CO2,
which it needs for photosynthesis,
and also, it gets a free home,
so it's a pretty good deal for everyone.
But these corals are in peril, so this reef on the left,
you'll see all the beautiful colors,
the browns and the greens and the yellows,
that's all healthy coral.
And then this reef on the right is called bleached.
So the reef on the right is quite sick.
So why is it sick? Well, I'm gonna tell you.
So this is our Earth. We're somewhere,
I'm not sure where you are, I'm somewhere up here,
and it's very chilly.
I think some of you all are down here in Texas
where it's a lot warmer today than, I know you think
it's cold, but you should be in Boston right now.
And the Earth is beautiful, but why is it habitable
where our other planets are not?
It has these greenhouse gases that make up the atmosphere.
These gases are water vapor, carbon dioxide,
methane, nitrous oxide, and together,
these gases make up our atmosphere.
And so what happens when the sun is shining,
the sun rays will come in and some of them will bounce off,
like you can see happening here,
but some of them will make it in.
And they serve to warm up the Earth,
and actually, our greenhouse gas
is what makes it actually habitable on Earth.
But what's happening now is that we are increasing CO2
or carbon dioxide into the atmosphere.
And like I told you,
this CO2 is one of the greenhouse gases,
so this is serving to have more gases
in this greenhouse layer.
So this is data from January 11th,
this is from Scripps Institute of Oceanography,
and this is looking through pretty deep time
through ice-core data, looking at the CO2 concentration
in parts per million on the Y axis
through time on the X axis.
So as you can see, CO2 levels in the atmosphere
were under 300.
And then since the Industrial Revolution, just after 1950,
we see this really strong increase in CO2 in the atmosphere.
And this was, you know, I guess a month ago now,
but for reference, when I, in 2010, when I started my PhD,
this number was under 400.
So just in this short amount of time,
we've been able to see this quite large increase
in CO2 in the atmosphere.
And what this means is that that's more
of these gases in our atmosphere,
so that means that more of the sun's rays
are getting stuck inside.
And what that means is that it's getting hotter.
So now we're looking at thousands of years ago,
so this is today.
So this is today's CO2 level, so this is above 400 here.
And so the orange is CO2 and the blue is temperature.
And what we can see
is that they're tightly correlated through time.
So when there's high CO2, there's high temperature,
and when there's low CO2, there's lower temperatures,
and they're tightly correlated through time.
And so what we're seeing in today's world when CO2
is at levels we haven't seen for hundreds of thousands
of years, we're seeing increases in temperature.
So this is looking at the 20 hottest
and 20 coldest years since 1880.
And what we can see is that the 20 hottest years
have all been since 1995.
And this is from 2018, but 19 and 20 and 2021
were all also now in the 20 hottest.
And so what does this do for corals?
This causes what I'm sure many of you have heard of
is called coral bleaching.
So this is that healthy coral,
where we can see its little polyp
with its algal symbionts inside.
And this is in its healthy symbiosis.
But when it's too hot, lots of researchers study why,
but the corals' symbiotic relationship
with this algae is lost.
And these are all the algae being expelled from the coral,
and the coral now just looks like a jellyfish,
so it's see-through and all you see
is the coral's calcium carbonate skeleton.
So it looks white, hence the name bleached.
And this process of coral bleaching can,
corals can recover from this if the stressor
like the high temperatures like go back down
or whatever stress was causing the bleaching,
and they can recover their symbionts.
However, like I told you, corals get their food
from their algae.
So if they're in this bleached state for too long,
they will die of starvation and then they'll be covered
in turf algae, and the rest is history.
So coral bleaching
is becoming a very massive problem globally.
It's been referred to as the coral bleaching crisis.
This is looking at the Great Barrier Reef,
and there's been back to back bleaching,
mass bleaching events along the Great Barrier Reef.
So in 2016,
one of the biggest bleaching events ever happened,
and anywhere you see a red dot is severe bleaching
and a green dot means there was no bleaching
or negligible bleaching.
And we can see that in 2016, it was most
of the northern Great Barrier Reef that gets hit.
And then in 2017, there was another bleaching,
so the next year, where we see the inner reefs in the north
were hit and then the central reefs were.
And then in 2020, we saw that all of the in-shore reefs,
all of the center of the Great Barrier Reef
and then the in-shore reefs again, were hit by bleaching.
So very few reefs on the Great Barrier Reef
have not experienced a bleaching event
in the last five years.
So what can corals do in response
to these variety of stressors?
They can bleach and die like we talked about,
which is a major bummer.
Or they can acclimate or adapt.
So this is an individual coral that we are working on
and this is a piece of the same colony,
so all of these are genetically identical,
and we put these pieces into a variety
of different environments and watched what they did.
And what they did, so some of them bleached,
so this one's a little bit bleached.
This is our control fragment, some of them turned
to this like crazy pink color, crazy purple color.
But the point is that corals can modify their physiology
to match their environment and try to survive
until the stressor leaves.
And they can also move away to a new place,
so disperse away to a new reef that may be
where the temperatures are a little cooler.
And you may say, well, Sarah, you just told me
that corals are like rocks.
So how can they move?
Great question.
So yes, in their adult stage, the corals look like this,
so this is a beautiful coral on the Great Barrier Reef.
And while the majority of their lifecycle is spent stuck
to the bottom of a reef, I'm now gonna tell you
about the intriguing sex lives of corals.
So corals do this really incredible
and fascinating activity that's actually
the reason I became a coral biologist.
So I was a student out at this marine station
and this professor was presenting on coral spawning
and I was like, I can't believe this is a real thing,
I need to go and see this.
And the rest is history.
So as an adult, when they're sexually mature,
corals spawn once a year.
And this is so crazy because when we think about the tree
of life, corals are quite basal.
So we think of them as they don't have brains,
they only have a nerve net, but still they coordinate
this, like, very intense and captivating behavior.
So as adults, in the warmest month of the year,
eight days after the full moon,
a certain number of hours after sunset,
depending on what species you are,
you will release your gametes.
And for most of the corals, they're hermaphrodites,
so they release these bundles of eggs and sperm.
And a single coral can't self-fertilize,
so they can't like make babies with themselves.
But what they do is they produce
these really cool spawns slicks at the surface.
And this is where external fertilization happens.
So the gamete bundles go to the surface,
explode, all the eggs and sperm are everywhere.
And they fertilize to produce these very cute
and very charismatic little coral larvae.
And these larvae can swim
and they have cute little behaviors.
So they live in the water column for weeks to months,
at which point they receive cues emanating from the reef
that say, hey, coral, you've like arrived at a reef,
you should like come live here.
And they do these very fun behaviors,
so this is a coral that has already chosen to settle.
This is another coral that has chosen to settle.
And all of this bright pink stuff or orangey stuff
is crustose coralline algae, which is one of the cues
that corals use to detect the reef.
So this larva here, it has a red butt,
so they swim with their butt forward.
And they're sensing their environment
and deciding on a place to settle.
And once they do, they find a place that they like.
This is what a coral recruit looks like,
and this is like after metamorphosis,
so they sit with their butt down.
And then the green part of this coral will become its mouth.
Remember, we saw on that picture the green mouth.
And then at this point, the coral
will start secreting its calcium carbonate skeleton,
it will acquire its algal symbionts.
So this picture here, there's its fluorescent protein.
And this is where it establishes symbiosis.
Then it will, oops, it will reproduce asexually
to produce the big colonies we see on the reef,
and once it's a certain size, it will also participate
in the annual coral spawning event.
So quite fascinating.
I'm gonna show you video, it's probably gonna be
a little bit laggy, but we're gonna give it a go.
So this is a coral spawning video, this is a male,
so I told you that there are mostly hermaphrodite,
but this species here has male colonies.
So this is what, what you're looking at here is sperm
and the sperm is inundating the water column,
so it's just fully saturated, cloudy.
It's like you, all of a sudden,
you go from being able to see really far away
to not being able to see your dive buddy next door.
And now this is the female, so the female receives cues
from the male with sperm in the water,
and these are eggs that are being released.
So these eggs are probably instantaneously fertilized
to produce larvae.
So this is what we call gonochoric,
where they have different sexes.
And the next one here, this is a hermaphroditic colony,
and you can see the synchrony of this coral
when it releases its gametes.
And we know the exact, like, to almost the minute
when these corals are gonna release,
we're gonna span out this, this footage
is from Flower Gardens, just to get an idea
of just how massive the amount of gametes
in the water column is during a spawning event.
We're gonna span out one more time here
and then you'll get to see how big these colonies are.
So it's quite, it's on your bucket list, people.
You should just, if you're not a scuba diver,
you should learn just to go experience
the coral spawning event because it's by far
the coolest thing in the world.
So with that, I'd like to pivot to kind of
what our lab has studied at the Flower Garden Banks.
So just a reminder from Kelly's introduction,
the Flower Garden Banks are a National Marine Sanctuary.
It's located, there's lots of banks in it now,
but the main banks that I've worked on
are Stetson, West Flower Garden Bank,
and East Flower Garden Bank.
And the two Flower Garden Banks are about 100 miles south
of the Texas-Louisiana border.
And I've had the complete luxury and privilege to go aboard
the Flower Garden Banks National Marine Sanctuary's vessel,
RV Manta, where we're fed like queens, I love it.
As a grad student, I loved especially just being fed.
And then we go out for the coral spawn
and it's such an adventure.
So why are Flower Garden Banks so special?
So the reason why they're so special,
one of the reasons Kelly alluded to in her introduction.
So this is looking at the percent coral cover globally
is in black and the blue line is the Caribbean.
So what we've seen is that historically,
coral cover was about 50% on most reefs
in the 1970s and 1980s.
But since then, what we've seen is rapid decline
in coral cover, and the Caribbean is particularly low,
sitting at about 10%.
So we've lost about 40% of reef cover
in the last maybe 30-40 years.
But Flower Garden Banks, so these are data looking
at a bunch of different things on the reef,
but I want you to focus on the red line here,
'cause the red line is the coral.
And this is looking at the East Flower Garden Bank,
so just one of the banks, through time,
so since 1989 when they started monitoring,
and these are data until 2019.
So what you can see is that mean percent cover,
so same axis here, we see that it's hovered around 50%.
So we're talking like 1970s levels
for like every other reef in the world.
So there is something very special and very fascinating
about Flower Garden Banks corals that allow them
to maintain this high coral cover in spite of global change.
And we think one of the things that might facilitate this
is that Flower Garden Banks corals
maintain very high genetic diversity.
So the more genetic diversity you have,
you can think about it as your repertoire
of ways in which you can respond.
So maybe some individuals aren't very good at something
and then something happens and then they get, they die,
but then there's all of these other individuals
that have all of these other things they're good at.
So diversity is great when we think about global change.
And so this is a study we published back in 2017.
So we sampled corals from the Flower Gardens, Florida Keys,
The Bahamas, Puerto Rico, US Virgin Islands,
Barbados, Curacao, Panama, Belize, and Mexico,
so across the wider Caribbean.
And then we profiled their genetics.
Essentially, it's like a massive paternity test.
And we asked how related corals are to each other.
And you don't need to know how to do genetics
to be able to read these graphs.
What these graphs are looking at
is if there's lots of different colors,
that means there's lots of different genetic backgrounds.
If there's fewer colors, like for example, in Mexico,
it's really dominated by this tan color in this graph.
Or for example, Puerto Rico is mostly dominated
by this dark brown color here.
Belize is mostly dominated by this teal color.
But when we look at Flower Gardens,
it has a little bit of all of the colors that you see,
so it has all of the colors represented in Barbados,
all of the colors represented in Curacao,
and all of the colors represented
at all of the places we sampled.
So what that means is that Flower Garden Banks
is really special because it houses all
of this genetic diversity, and that's gonna be important
as the climate changes because it offers corals
more opportunities to evolve as climate change progresses.
The second thing we've looked at
is the resilience of Flower Garden Banks corals.
So I've told you that they're very genetically diverse.
And now some of the work by these amazing students
that you see pictured here,
so these are Boston University marine program students.
This is a picture that was taken in December this year.
And we did some experiments looking at Orbicella franksi
and Orbicella faveolata or the great,
I think it's called the great star coral,
from the Flower Garden Banks,
both of these species are endangered species.
This is what it looks like,
so cute with its little polyps and its little tentacles.
So we have these corals on these dishes,
and when we put them into these different treatments
and ask, how do these corals respond
to a variety of different stressors?
So this is what the corals look like,
so this is one of our hot tanks.
So we can see all of our different,
we call them coral nubbins.
And these are them chilling in the hot temperature.
And what we need mean by hot here
is that we have a control condition here,
so this is an 11-day experiment
this is all done within a class at Boston University,
so we do this in a, it's a teaching moment for all these,
all of these students get to participate
in real-world research.
And so we have a control condition that's maintained
at the 26.5C, which is where these corals really like to be,
this is where they've been grown for the last couple years
in the lab, they grow really well, they love it.
And then we took one set of tanks
and we slowly heated them up over the 11 days.
And we heated them up all the way
to 35 degrees centigrade, which is a temperature
that Flower Garden Banks corals never experience.
So it's well outside the historical temperatures
that these corals would've experienced on the reef.
And then we also took these corals all the way down
to about 16, or actually, no, we didn't get,
we were hoping to get to 16, but we didn't.
We got down to about 17 and a half degrees Celsius,
so pretty cold for these corals,
we consider about 18 degrees to be a thermal minimum
for corals, so it's about at their threshold.
And I don't have data to show you
because we just did this experiment,
but I will tell you that we didn't see any bleaching,
which is super crazy because these temperatures,
both the lower and the upper,
are well outside what these corals experienced
on the reefs that they came from.
So this suggests that these Flower Garden coral
are actually highly resilient, which is really good news.
So the other cool thing that we've done
is during the spawning, we've collected gametes
from these corals as they're spawning,
and then we've cultured their larvae,
and then we've asked questions about their larval biology.
So one of the things, one of the experiments that we do
is we take these larvae and we ask them to settle.
We offer them that crustose coralline algae
that I showed you in that little GIF where,
and we ask them, are you ready to settle?
And we do this every day since they're born.
So we start at one day post fertilization,
so when they're one day old, and progressively all the way
until 120 days, until they're 120 days old,
and we asked, will you settle for us?
And what we found is that this species of coral,
this brain coral, Pseudodiploria strigosa,
it was willing to settle for us at three days.
And it settled for us all the way to 20 days.
This species here, Orbicella franksi,
which is the one that we showed previously
that was really resilient, it was, it didn't settle at all.
It was not willing to settle until 20 days,
it needed to spend 20 days as a larva until it was ready
to receive that cue and settle.
And then we kept them in the lab until 120 days
and then offered them settlement again
to see if they would settle and they still did.
And then, so we modeled out with ocean currents
and asked, how far can these larvae go?
And so what we found is that the species
that has the short duration mostly just chills
and stays and comes back to Flower Gardens
or goes off into the abyss and probably the larvae
are just eaten in the water column
'cause there's no more reefs over here.
But what's very fascinating is that,
here's the Flower Gardens, is that if we model out 120 days,
we see that there's a decent chance that these larvae
will be taken over here all way through the Florida Keys
up along Florida and out up to Boston,
we don't have corals in Boston,
but that's where the model's predicting
that the larvae would go.
So what we found is that there's a probability
that Flower Garden Banks can provide baby coral
to Florida reefs as well as Cuban reefs.
So this is very exciting,
this idea that these resilient corals
with this huge amounts of genetic diversity
could move throughout places like Florida
where their reefs are very degraded.
So when we think about this from a conservation perspective,
we have these adult populations of corals at Flower Gardens
that exhibit this very high genetic diversity.
And then we've also shown that these corals
are able to be very resilient.
And then, so we could imagine that these resilient, oops,
sorry, these resilient and genetically diverse corals
are moving between reefs.
So this is to say that Flower Garden Banks absolutely
should be a priority for conservation
because what we're seeing is that it's a genetic sink
and source, meaning that it has a lot of genetic variation
and that this genetic variation can move between reefs.
So it could source other reefs
that are less healthy and give them babies.
The second thing we've seen is that the percent coral cover
at Flower Gardens is really high.
And so what that means is that potentially,
the Flower Garden Banks could be a source
for restoration material for other Caribbean reefs
that are more degraded, for example, Florida.
I tend to use Florida because their reef cover is very low.
So with that, that's kind of a snapshot into our research.
I'm always happy to nerd out and talk in more detail
about any studies, but I just kind of wanted
to give you a smattering of some of the work
that we've done at Flower Gardens.
So with that, I'd like to do some acknowledgements.
So I'd like to acknowledge the people up in Massachusetts,
where Boston University is and where most of our work
has been done, just a land acknowledgement.
And the second thing, I'd like to thank my lab,
so this is a little bit outdated photo,
we have more people now, but these are all the people
that do all the hard work.
I'd like to thank all of our funding sources,
including NOAA, who's funded some of our work
at Flower Garden Banks.
I'd like to thank the University of Texas
where I did my PhD, and it was really the place
that allowed me to be close enough to Flower Gardens
to really get an obsession with these reefs.
I'd like to thank the sanctuary, like I said,
I've been going out with them for many years now,
and I'm always grateful to be offered the opportunity
to sail with them out to Flower Garden Banks
and dive with their amazing scientists that work there.
And lastly, I'd like to thank Fling Charters,
which is a dive, a recreational dive company
that offers divers going out to Flower Gardens.
So if you have a chance and you're interested
in seeing the Flower Garden Banks reefs,
the Fling is a great way to go out there
and they also have a lot of tasty food.
And with that, if there's any questions,
I'd be happy to take them, or I guess you put them
in the chat and then, yeah.
But thank you so much for listening.
Kelly: Thank you, Sarah, that was great.
Folks, we will take questions right now,
if you do have questions, please type them
into the question box available
in the control panel of the GoToWebinar system.
And we have about 25 minutes to take questions for Sarah.
And we'll start with a few that have already came in during
the course of the presentation.
Sarah, are there coral anchor type environments
that can help grow coral independent of higher temperatures?
-: Coral anchor?
Kelly: Yes, that's what it says,
coral anchor type environments.
-: So I think we're thinking about like,
are there residual like places
where we can find resilient corals, is that maybe?
So I think when we think about, we've thought a lot about,
so I'm part of the Coral Restoration Consortium.
And we're trying to think a lot about
where should we pull corals from
for these restoration programs. These restoration programs,
just for a little bit of background,
are taking corals off the reef and fragmenting them.
So having these kind of like repositories
of coral genetic diversity and then outplanting them
to different places to try to increase artificially
through humans, like, and usually with adults,
but they're also trying to do it with larvae too,
the genetic diversity on a reef.
So when we think about, are there places
that we should source those corals from?
I mean, Flower Garden Banks is a great idea.
But it might be a permitting nightmare.
But also, we've shown that corals
that are from more thermally variable environments,
so environments that experience higher highs and lower lows,
tend to be more resilient, so those could be like sources
of resilient corals.
And then as far as, can you make corals more resilient?,
there's been a little bit of work trying
to like prime corals to be stronger.
So one of the things you can do
is you can kind of like hit them with a stress but not like,
kind of like, I mean, think about
the way the COVID vaccine works,
it's like totally different mechanism, but you know,
you get this vaccine and it mounts this immunity response,
so like you get this memory of how to respond to this virus.
It's like, you could imagine the same thing
with heat stress, it's a totally different mechanism,
but where you hit the coral with a slightly hot temperature
and then that should prime it to be better
when it sees that temperature again.
So these are some of the ways that people are thinking
about restoring coral populations
and like priming them for resilience.
Kelly: Okay.
Next question.
Why do corals spawn after sunset?
-: That's a great question, it's probably,
I don't know the, like the why.
But I imagine that it's like, so at the Flower Gardens,
you know, there's probably, I don't know,
half a dozen to a dozen corals that spawn on the same night,
so it's not as crazy as far as like species diversity.
But you really need to make sure that you're going
at the same time as everybody else,
because I told you that you can't self.
So it's not like you can,
you can't make babies with yourself.
So you need to make sure that other corals are going
at the same time, so I imagine that it's been evolved
because light is a very clear cue
and we know that corals can,
even though they don't have eyes,
that they can perceive light.
So it's probably a way for them to ensure
that they're all spawning at the same time.
But I don't know why they wouldn't do it like in the morning
because we know that like some sponges spawn in the morning,
like a certain amount of time after sunrise.
So yeah, I'm not sure why it evolved this way,
but the nighttime spawning is consistent for all corals.
So although I don't know brooding corals,
brooding corals do something a little bit different
where they go off of lunar light,
but they spawn several times a year,
I know less about brooding corals.
But definitely for the broadcasters,
I don't have the answer for the why,
but that's a fascinating question.
Like why didn't they decide to spawn in the morning?
Maybe it's like to avoid predation in the water column?
I don't know, that's a good question.
Kelly: Okay, hopefully, we've got some more good ones
for you.
Why do you put the coral aquariums with UV light?
Is there a correlation between the resistance of the corals
to extreme temperatures and the size of them?
So two questions in one.
-: So two questions, so the first one
is why do we put them under UV light?
Kelly: Yes.
-: So it's not actually UV light,
it looks like it, it's actinic light.
So it looks very blue in the aquariums,
but it's actually similar to the wavelengths
that they would get on the reef.
So we have lights that are programmed to be similar
to the spectral qualities of a reef,
so for anyone out there that's dove,
one of the first things that you'll notice is that,
as you go down in depth, the light is attenuated.
So shorter wavelength light, which are more red colors,
red, oranges, yellows, those get attenuated first.
And that's why, when you're in the ocean,
everything, especially when you're deep,
everything looks blue or purple.
But if you took down a light,
what you see is that there's actually a variety of colors
that you've missed because those light wavelengths
got dissipated early as you were moving down.
So that's why shallower reefs
can sometimes look more colorful.
But in reality, they're both just as colorful
as like a shallow versus a deeper reef.
It's just that we don't see the light
because all that light's attenuated.
So the light that we're giving our corals like,
for example, in this picture here, it looks pretty blue,
but that's actually pretty similar
to the light that they would receive on the reef,
which is actually pretty blue light
because even in the first 10 feet of the water column,
the majority of red light's actually attenuated.
So if you put them under UV light though,
they'd be very stressed.
So that would elicit a stress response for the corals.
Yeah, what was the second part of that question, Kelly?
Kelly: The second part was,
is there a correlation between the resistance
of the corals to extreme temperatures and the size of them?
-: Hmm.
So like an age, so size generally correlates with age.
So is there correlation, so definitely,
I don't have an answer for that.
So one of the, like the only thing I can think about
to sound smart, so I actually don't know.
My feeling is that an older coral would have,
I sound like a grandma or something,
would've experienced a more diverse set of experiences
'cause some of these corals can live for hundreds of years.
Like they're definitely, like if you see this giant coral
in the reef, it's older than you for sure.
So you could imagine that that coral has like seen its time.
So when you think about that priming idea,
my feeling would be that bigger corals would be what's left.
So if you were young and resilient
and you made it through like a couple bleaching events
and you were still there, well then,
you're like pretty resilient.
Whereas little ones, it could be that like individuals
from like that little population on the reef,
like let's say all the juveniles, not,
like maybe there hasn't been a bleaching event yet
that like knocked out the kind of losers.
So we can think of the biggest ones on the reef
as being like the long-term winners,
like they've won so far.
And the other really interesting thing to think about
is that, when they establish the symbiotic relationship,
so they settle and then they don't have any symbionts.
They establish symbiosis.
But if they're very small, they're like very confused.
So they're just like testing the waters,
they'll like associate with any algal symbionts.
But as they grow up, their immune system,
so they actually have innate immune systems.
So we have innate and adaptive immune systems,
but corals have an innate immune system.
The coral will kind of like grow up,
its immunity kind of turns on,
you can think of it like puberty or something.
And then that immune system will kind of chuck out,
so get rid of the algal symbionts
that are like not the best ones.
And then eventually, when those baby corals grow up,
its algal symbiont community will be very similar
to the algal symbiont communities
of the big corals on the same reef.
So in that way, I could imagine
that if you had the wrong algal assemblage,
wrong meaning like you haven't weaned it out yet,
you might be more susceptible
to a stressor than maybe a bigger coral
that has a more established symbiotic relationship.
But I don't actually know the answer to that question,
so that's just me kind of thinking about what I know
and how it might relate to what you asked.
It's another great question.
Kelly: Okay.
Next question. Wwhat are actions you would recommend sharing
with the public to help protect coral reefs?
-: Yeah, that's a great, so I don't like to get political,
but the best thing we can do is vote people into power
who are actively pushing for mitigating CO2 emissions.
So that's the most direct way that we can make change.
You know, obviously, there's lots of small little things
we can do in our lifestyle, Kelly and I were chatting
about it before we started, before we got
on the official webinar, you know, driving less,
so just ways in which you can reduce
your personal footprint.
But at the end of the day, these personal footprints
are so small in the grand scheme of the CO2 problem
is that it's really we need like broad policy change
to be able to reduce emissions at a rate
that we think is gonna be required
to maintain healthy coral populations.
I think investments in fun technologies that are pulling,
like crazy stuff like pulling CO2 and making,
like we've thought about making like coral biofilms
on roofs where like you could accrete this biofilm
that like pulls CO2, 'cause CO2 is used
in the calcium carbonate process.
So funding research into these sorts of things
is obviously a way that people can do personally.
You know, divesting your investment portfolio away
from fossil fuels is a great way to make a personal impact.
So I really believe that as people, as part of society,
we can. Shat we spend our money on says a lot
about where our values are.
So making sure that we are supporting companies
and businesses that represent our values.
So those are kind of like tangential ways.
There's obviously more direct ways, so you can,
there's lots of coral restoration happening actively,
throughout the Caribbean especially.
Pacific Islanders are. Like coral restoration
is happening everywhere, it's kind of mind blowing
how much coral restoration is happening.
And so getting involved with one
of the restoration consortiums
would be a great way to be active.
But yeah, so those are my,
they're kind of more opaque things but, you know,
I don't know that, you know, there's lots of small things
we can do in our day-to-day lives
that I think make an impact.
But as far as corals, it's really CO2.
We need to reduce CO2 in the atmosphere like yesterday.
So that's the main thing we need to think about with corals.
Kelly: Sarah, you just reminded me
of something I heard on TED Talk the other day
by researcher Phil Dunstan.
He said the ocean begins at your front door.
So what you do at home matters.
-: Yeah, I mean, I think about that a lot, so, you know,
but then I have like devil's advocates
that are always calling me out 'cause I live in Boston,
but my family lives in Canada on the west coast.
So I fly to see them.
I fly to Flower Gardens, or not fly there,
but I fly to Texas to go there.
So I don't, I have like a philosophical problem
with like putting it on individuals because I think that
it's meant to make us feel personally guilty.
But at the end of the day,
what's brought us to this problem is policy.
So I do think individuals, like we should feel accountable,
but we should push our representatives to represent us.
So if corals are something that you are passionate about,
then, you know, if Flower Gardens are a place
that you wanna visit and you wanna see these healthy reefs
in the future, then I think that telling your politicians
that is great. Like the expansion
of the National Marine Sanctuary was amazing.
And that happened with a lot of pushing,
so I think that these personal actions are very effective.
Yeah.
Kelly: Thank you.
Next question, what is the lifespan for larval disbursement?
How long can larvae live
in the water column before settling?
-: So that's an awesome question.
So one of the things I like didn't touch on yet that I think
is something worthwhile is that, when we culture corals
in the lab, they are in a little bucket.
And they just live there, there's no predators,
there's nothing, they just chill.
And we change their water and they just,
it's like the safest environment, like kind of like a zoo.
So there's no predators.
Coral larvae are lecithotrophic,
which means they don't feed,
so they just have their reserves
from the maternal egg mass that they had.
They can essentially go into like a form of diapause
where they don't really do anything, they just chill.
And so the longest I've been able to keep larvae
in the lab was 120 days, but that was
mostly 'cause I was like tired of keeping them in the lab.
They would've, I think, lived longer
if we'd offered it to them.
That said, the plankton is a very different environment
than these culture dishes with no predators and, you know,
no UV, so one of the questions earlier was talking about UV,
so UV can have a negative impact on larvae
'cause they're right at the surface.
And so that can cause strong damage,
so really like the plankton is not a cool place to be
if you're a coral larva, because it's not like
you can like run away from like, they have cilias,
they can swim, like I showed you their behaviors,
but it's not like they're, like they're not faster
than like a copepod or something.
So whatever wants to eat them kind of can eat them,
and this like whale shark sitting right here
would totally eat all sorts of larvae.
So my guess is is that, you know,
I don't think that you would see coral larvae
beyond a few months in the plankton, in the real world.
That being said, when, you know,
I showed you those probably billions of babies
at the surface in that surface slick.
99.9% of those will die.
They'll be eaten, they'll die, genetic load,
all sorts of reasons why they die.
So the majority of them don't survive and come to the reef,
so it's really like sweepstakes.
Like it's very rare that a recruitment event happens
just because of everything. Like you have,
to have successful fertilization.
You have to, the larva has to survive,
it has to actually find the reef.
So the currents actually have to take it to the reef.
It has to find the reef, it has to settle,
then it has to not get eaten by all the stuff
that wants to eat it on the reef.
So really, life of a larva is quite intense.
they should probably make a movie about it.
I bet it would be good.
Yeah.
Kelly: That's wonderful.
There's another question about the eggs themselves.
Are the individual eggs visible to the naked eye
or are they microscopic?
-: Amazing question, and a funny story with this one.
So yes, you can totally see them with the naked eye,
unless you age.
I've noticed with age that I have a harder time.
Like I think I need to start wearing reading glasses
when I do coral spawning work now because, you know,
we do a lot of counting, like egg counting, in our work,
and I'm finding that I'm squinting and, anyways.
And it's funny 'cause I used to make fun
of this woman I collaborated with in Australia
and she was like, she'd say, oh, here's this thing,
all the wells are, each have one in them.
And I'd look in there and there was just like, I don't know,
just like totally off like what she said it was.
And then I found out
it's 'cause she, like, needed reading glasses
and I, like, made fun of her at the time and this is,
you know, 15 years ago or something.
And now I'm like in the same state, so,
but yes, to the naked eye if you have good vision.
Kelly: Great.
And does the coral spawning here have any relation
to deep water corals, say, off the Mid-Atlantic?
-: I don't know about coral spawning up the Mid-Atlantic,
but one of the things I didn't touch on here
'cause I wasn't sure about at the time,
obviously, I would've.
So one of the cool things we did, what year was it? 2019.
It was actually funded by NOAA, we did a telepresence cruise
to the Flower Gardens and we used
a remotely operated vehicle, so an ROV, to go down
and monitor coral spawning at depth.
So we're talking like 45 meters, so quite deep.
So the same species can live quite shallow
all the way down to 45 meters.
So like at Flower Gardens, I think the top part
would be probably like 21 meters.
Sorry, let me do feet, 65 feet to like,
I don't know how many meters, 50, 150 feet or something.
And they do tend, they spawn around the same time.
So there does seem to be spawning synchrony between
the depths, but I can only speak from the Flower Gardens,
I don't know of any research actually
that's monitored deep water Caribbean coral spawning.
And I think the reason for that
is because, I told you, it's so predictable and it like is.
But you imagine, for anyone out there that's a diver,
even 65 feet is quite a challenging depth
to dive for a long time. Like, we dive with nitrox
and that gives us about 45 minutes underwater
at like 80 feet.
But if you wanted to dive the mesophotic,
you'd have to be a technical diver to be able
to monitor the coral spawning, otherwise, you'd get like,
you'd run out of air, you'd need a rebreather.
So you'd need a lot of like technical expertise.
And then you couple that with like doing tech diving
at night.
So it's, the spawning dives are quite intense
'cause you're going down in this Flower Gardens,
this blue water diving, 'cause you're going down 60 feet
until you get to the reef cap.
And then you lose all visibility because they're spawning,
so not a lot of people have done
deep water spawning observations
for these logistical reasons, but that's why the ROV work
was really cool.
And we did show that they spawn around the same time.
Yeah.
Kelly: Next question, do corals only communicate
with each other via spawning, are the signals planned,
and what conditions need to happen
to stimulate the spawning?
-: Can you read the first part of the question again?
Kelly: Do corals only communicate
with each other via spawning, or maybe only during spawning
maybe is what they mean?
-: Yeah, great question.
So we definitely think there's other things in the water
that cue spawning.
So obviously, it's like the lunar light,
so the daylight and the lunar light interact
to tell the coral ish when to spawn.
But what's interesting is that if you like hold your light
on a coral, like it won't spawn for you,
it's really annoying 'cause you're like waiting for it,
you can see that they're set, you can see the gametes
in its mouth and you're like waiting.
And then you take your light away and then it goes.
But some really fascinating work that was done
by Don Levitan from Florida State University in Panama,
where they like looked at corals up and downstream
from each other and when they spawned.
And there was definitely this, like, spawning
that happened through space.
So like, so there's some, I think,
queuing off of actual gametes,
so like maybe if one goes early,
the coral next to it's like, oh, that guy already went.
I should go too.
So I think there's some like cuing on spawn,
but I think there's also potentially like
water-soluble like hormone-like chemical,
some sort of chemical signature too that, like also tells it
to spawn, because one of the things we've noticed
is that when...You can do ex situ spawning,
so you can take a fragment of a coral
and take it to the surface and it'll spawn.
But if you do it like many days early, it's like
it didn't receive enough info or something,
so they often don't spawn.
So you almost need to like take the coral off the reef
like the day before or the day of spawning
to get them to spawn ex situ.
The other cool thing you can do
is when you're doing spawning ex situ
is that you can bamboozle them and cover them
with black plastic to like simulate like the sunset.
And then they'll spawn early, which is really nice
'cause some of those corals spawn at like midnight.
So then you're spawning all night and making cultures
and you're up to like five in the morning.
But this way, you can like bamboozle them
and they'll go a little bit earlier for you.
So that's, I think I answered the first part
of the question.
Kelly: The other part of the question was, you know,
what are those cues that tell corals to spawn,
so I think you kind of answered the whole thing.
-: Okay, cool.
Kelly: Folks, at this point,
we are nearing the end of our time,
but Sarah has agreed to stay on for a little bit longer
about another 10-15 minutes past our scheduled end time
to continue answering questions.
We have a whole list still going for you, Sarah.
But what I'm gonna do now in the interest of people
who do need to leave at 7:30 is I'm gonna wrap up
the presentation and let you know the final details
that you need to know about what's coming up next.
And then we will come back to Sarah
and the question and answer period,
so if you'll hold on a second,
I'm going to start showing my screen again.
And there we go.
So for those of you who do need to leave
and for all those of you who've been here all this time,
thank you so much for attending this Seaside Chats
about the Sex Lives of Coral: From Spawning to Conservation.
This is the first in a series of four presentations
we are offering this month.
We invite you to register for the remaining chats
by visiting us on the web at flowergarden.noaa.gov.
We promise the other topics will be just as engaging
and informative, and you can see them listed here
on this slide.
Next week, we'll be talking about the future of fisheries
in the climate-driven Gulf.
The following week, we'll be discovering climate history,
in the skeletons of living corals.
And on the 23rd, we're gonna go to Hawaii
and talk about how humpback whales feed the ocean
around Hawaii, not how it feeds the people.
It's not about people eating whales,
so please don't get confused, but how those whales
are important to the overall environment
around the Hawaiian islands.
If you have, we welcome any feedback on this
or any questions you have, please submit them by replying
to the follow-up email you'll receive after the webinar
or by emailing us at flowergarden@noaa.gov.
Today's presentation has also been part
of the National Marine Sanctuaries Webinar Series,
as I mentioned earlier.
And while Seaside Chats last just one month,
our national webinar series continues throughout the year
to provide educators with educational
and scientific expertise, resources, and training
to support ocean and climate literacy in the classroom.
Be sure to check the National Marine Sanctuary's website
for recordings of past webinars
and the schedule of what's to come.
As a reminder, our recording from today will be posted there
and a link to that will also be posted
on the Flower Garden Banks
National Marine Sanctuary website.
Following this webinar, all attendees
will receive a PDF copy of a certificate of attendance
that provides documentation for one hour
of professional development for today's presentation.
This includes our Texas CPE provider number
for those of you who are Texas educators.
If you are an educator outside of Texas,
please use this certificate to help get your hours approved
in your district.
If you require additional information,
please feel free to contact me at flowergarden@noaa.gov.
There will also be a short evaluation that has questions
for you to answer following today's presentation.
Please complete this survey immediately
after signing off the webinar.
It should only take about three minutes to complete
and we really appreciate any feedback
you are willing to share.
Thanks again to Sarah Davies for a great presentation
about the Sex Lives of Corals
and their implications for coral conservation
in Flower Garden Banks National Marine Sanctuary
and the rest of the world, and thanks to all of you
for taking the time to join us.
This concludes the official part of the webinar,
but we are going to stay on for about another 10
to 15 minutes to continue answering a few more questions
that people have for Sarah.
All right, Sarah, are you ready for some more?
-: Yeah, I'm ready.
Kelly: Okay.
Next question.
How possible is it to grow corals in tanks in the classroom
and have them transplanted to reefs for restoration?
-: I wish I could say it would be really a great idea.
So all the aquaria are challenging,
so it's probably one of my biggest stresses in my job,
is making sure that I don't like kill all the corals.
So we have a system that's like automated through WiFi
that sends me a text message whenever the temperature
is like, so the temperatures need to be maintained
at very consistent happy temperatures,
and if it gets too cold, they bleach,
if it gets too warm, they bleach.
So all of our systems are on like backup power.
So my feeling is that
it wouldn't be a great classroom activity. That being said,
I didn't talk at all about corals
that live up here in New England.
But there are some facultatively symbiotic corals,
which means they can live with
and without their symbionts naturally.
We just dive for them off the coast here,
which is a lovely little system, and during COVID,
we really studied these corals a lot.
And they are much more resilient than the tropical corals
and much easier to keep in aquaria.
That being said, they're not actively used for restoration,
but if you wanted to use them for like teaching,
you could monitor their growth.
They have really big polyps, so those like anemones,
so you can like feed them brine shrimp.
So those would probably be like the best option.
There's also, we use a model for coral bleaching,
this Aiptasia anemone.
If you Google Aiptasia, it's A-I-P-T-A-S-I-A.
And it's like a pest, so that you could definitely keep
in a classroom, and they also bleach.
So they have a symbiotic relationship
with algae in the same family as corals do.
And those are very, I use those for teaching a lot.
And students love them, you can like feed them
and they can like, they're fun too.
But I wouldn't suggest tropical corals
in a classroom setting, the tanks are quite a lot of time
for upkeep.
Kelly: Okay, next question.
Oh, when the algae leave corals during warming events,
is the algae that decides to leave
because they would die inside the polyps
or is it the coral that expels it?
-: Yeah, so that is like the best question
and that's like really the crux of what our lab
is really interested in, is like, what's the mechanism
of what's called dysbiosis, when the symbiotic relationship
is lost.
And there's hypotheses, so we think that what happens
is that when algae get angry, so when it's too hot,
their photosynthetic apparatus starts malfunctioning
and produces something called reactive oxygen species.
And these reactive oxygen species, or we call it ROS,
will infiltrate into the coral and it's toxic.
So it actually poisons the coral.
And then this hypothesis, this reactive oxygen hypothesis,
thinks that it's the coral that makes the decision
to expel their algae.
There's other hypotheses that think it's the algae
where they're, like this home sucks,
it's really hot and I don't like it.
The interesting thing about
the tropical coral algal symbiosis
is that the tropical coral, like I said,
without the algae, it will eventually die.
What I didn't tell you is that the algae can grow
in culture for like ever, they live in sediments,
they can infect other hosts on the reef,
like not just corals, they infect clams and sponges,
other little critters on the, like worms.
So they can live in a variety of hosts.
So they're maybe less obligate than the coral is.
So there is, but it's an area of active debate.
So I think that like, if you asked me
which like camp I sit in, I think it's like,
I think what happens, I know no one asked me
what camp I'm in, but I'm gonna tell you what camp I'm in.
I think what happens during bleaching
is that the coral loses control
of the symbiont's environment.
And then that makes the symbiont go crazy.
And then the coral is like bleugh
and then like spits it all out,
but I think it starts with like the coral not being able
to tightly regulate that symbiont's space and that,
because I think it's the variation
in how good a coral is at doing that.
That explains a lot of the variation
of bleaching we see between, like, species or populations,
like the questions about, like, which corals
are more stress-tolerant.
It's like, there's a lot of variation out there,
and I think how good a coral is at regulating
its symbiont's environment explains a lot
of bleaching patterns.
But we don't know.
If you knew that, you'd be like a very, very cool scientist.
Kelly: Cool.
Can corals be farmed or is the animal-plant symbiosis
only possible in a natural environment?
-: No, so, I mean, they're actively being restored,
so there's like, if you Google
like coral restoration Florida, for example,
they can totally be farmed.
They can be farmed ex situ, so where you have tanks
and you grow them up.
So Mote Marine Lab in the Florida Keys
does this really cool technique where they,
it's called micro-fragging.
So they cut the corals into like the tiniest little pieces
and then they grow super fast.
We don't know why, but it's super cool.
So that's like ex situ restoration.
There's also in situ restoration where they,
it's super cool, they have like little,
they call them coral trees, I think,
and they hang them out in the ocean like
above like a sand bar kind of thing,
like out in like really clear water,
they have like these white trees,
and then they hang all these corals,
and they grow super fast on them and they,
there's like, I mean, I wish I had a photo.
But it's fascinating.
So yes, you can do this and people are doing this
and it's an area of very rapidly evolving research.
Yeah.
Kelly: Wonderful.
Good question here.
While it's great that some corals are resilient
to warming temperatures that can be associated
with climate change, are there enough resilient species
to maintain sufficient biodiversity globally?
-: That's a tough one, so based on what we know,
which isn't everything, you know,
I feel like we've just scratched the surface
about how the mechanisms by which corals can evolve.
One of the things I didn't even touch on
is there's the coral host, there's the algal symbionts,
but there's actually also a consortium of microbes
that live in and on top of the coral and the algae.
So there's this, just like we have our human microbiome,
there's coral microbiomes, and those have been linked
to resilience too. So if we think about,
there's like these three partners and all of their,
and by three, I mean like the micro,
I'm lumping all of those thousands
of bacteria type into like one.
And so all of those possible interactions
create opportunities for evolution,
all of those in interactions between all
of those possible partners.
So my job, my lab jokes I'm like a serial optimist.
So I like to think that we just don't understand enough
about how these interactions might modulate evolution
of the coral holobiont, meaning like all of it together.
And I do think that there is reason for hope,
places like Flower Gardens are one of them.
But if you read the literature
and looked at the modeling studies,
I think that, based on the information that we have today,
the projections for business as usual are very bad.
Very few remnant reefs, only highly resilient species
of very low species diversity, and reefs not functioning
in the form that they function in today.
So as you get less species,
you get less structural complexity,
so you get less opportunity for other reef invertebrates
and larvae to like live and associate with the reef.
So that's like, structural complexity and species diversity
is like a really important thing for like the ecology
and function of the ecosystem.
And so we think that under a business as usual scenario,
the reef structure and the diversity
will be very low or remnant if we continue on our path.
That being said, I'm an optimist,
and I think that there's things that we don't understand
and ways in which corals might evolve
that we don't understand yet.
Kelly: Next question.
Are there ways that we could increase recruitment on reefs?
-: Yeah, and people are doing stuff like this,
like restoration things.
So people are doing like larval transplants,
so taking like big chunks of spawn and moving them and,
or like outplanting recruits onto there.
You know, crustose coralline algae tends
to be the major signal to settle in corals,
so this is this coralline algae, it's pink.
And it's kind of like the glue on the reef.
If you look at a reef aquarium, you'll see like pink stuff,
that's like what corals use to cue
that that's a healthy reef.
So I could imagine things that are manipulating
the crustose coralline algae on the reef,
that would be good.
We know that herbivore, so things that remove algae,
are very good for coral recruitment,
so things like controlling fishing pressures
can interact with coral recruitment.
So No Take Zones and things like that
can facilitate recruitment.
But I think the question that the listener is more asking
is like, more like engineering technologies.
And there's been a little bit of work into like biofilms
that can attract corals.
So that's like an active area of research,
or certain chemical signatures that attract corals.
Colors, so certain colors, like weirdly,
corals can tell different colors,
even though they don't have proper eyes.
And so that's an active area of research as well, so,
but yeah, I don't work in that area,
but these are all the things I've, like, heard about
that sound really cool.
Kelly: Okay, is there any fear that transplanting corals
may be detrimental to the current population
you're replacing them with?
-: Absolutely.
Yeah, so there's lots of fear, you know,
human intervention is, if we look historically, is not,
we tend to have very little foresight
into the types of bad things that might happen.
So the way that like I think about restoration
is it's a last option, right?
So the majority of reefs that are being restored
are very bad.
So they have very low coral cover.
So it's like the risk of, it's not, it feels like less
of a risk because there's really not a lot
of diversity there, so one of the things we worry about
in restoration is that you will bring a genotype, let's say,
so like a genetic background to that reef,
and then it will swap out all of the diversity
that was already there.
And the argument like against that is, well,
there was very little diversity to start with.
And the trajectory of that reef was so bad that like,
that genetic diversity that was there
maybe wouldn't be there tomorrow.
So, you know, I think the places
where restoration's being actively pursued
are areas where the reef is in very bad shape,
so there's almost more risk in doing nothing
than trying something.
So that's one thing.
We do worry a little bit
about inbreeding depression, so that's the idea
that you might get like weird genetic combinations
if like a certain genotype outperforms everybody else.
But in general, like we think
that more genetic diversity is better.
So I think there's risks, there's also like,
you can also reduce risks by like transplanting larvae
that don't have all of the consortium
of microbes that we talked about,
so one of the things like that we worry about
is like moving disease between reefs, for example.
So there's been conversations about like,
should there be a period of quarantine where the coral
is taken into captivity, grown in, I don't know,
sterile water, and then transplanted after three months
of let's say it looking healthy, something like that.
But there's no way to know because it might be
that it was healthy, but then something
in that new environment triggered something,
and then now that coral is diseased.
So it's really, we don't know enough about it,
but the majority of restoration practitioners kind of feel
that like, we're to the point with some reefs
where there's a bigger risk of doing nothing.
Kelly: Well said.
How long can corals live for and what percentage
of estimated total coral types have we lost forever,
as in extinction?
-: So we've, okay, I'll answer the first question,
so the first question is it varies depending on the species.
So some of the faster growing species
we think live like 50-100 years.
And then, one of the talks is actually on coral coring
where they can actually like age a coral.
So you should come to that next Seaside Talk,
I think it's like two from now,
where the woman's gonna talk about coral coring
where we can actually like age it.
And some of the corals that we've cored
have been hundreds of years old.
So the estimate is that there's like corals out there
that are like 500 years old, so they can live quite long.
And then the second part of that question, I forget already.
Kelly: And a percentage
of estimated total coral types we've lost.
-: Yeah, so I think that's a really hard question to answer
because I think we're just scratching the surface
of understanding the way that coral genetic diversity
is partitioned across the seascape.
So there's no question that we're losing populations
of corals.
But as far as species, I mean,
you can get into a whole rhetorical debate
about what is a species.
But one of the things that our lab keeps finding,
for example, is that when we profile the genomes of corals,
we find this cryptic genetic diversity
that we didn't even know was there.
These two corals that look morphologically the same,
when we profile their genome,
they're totally separate species,
they haven't interbred in hundreds of years.
And so there's, I feel, like this wealth
of kind of like underestimated diversity out there so,
you know, when we lose a population,
are we actually losing a cryptic species?
Like, I don't think we have the answer to that question.
But, you know, corals are going locally extinct,
like that's a real thing that's happening, in Florida,
I think there's one colony of Dendrogyra,
which is the pillar coral, like it's locally extinct.
It is elsewhere in the Caribbean.
And then also Acropora cervicornis and Acropora palmata,
there's so few individuals that naturally live on the reef.
So those are the two species
that are like very actively restored in Florida
that it's like, I mean, so few individuals that you'd,
you know, there's one individual left
in the population, like that, unless it has sex with itself,
I mean, that population's extinct.
So even though there's one genotype,
it's extinct because it can't have sex with itself.
So I think that's, I can't say
whether we've lost species, but I can say
that we've grossly underestimated genetic diversity.
And so I think that we're probably missing,
we don't even know what we're losing.
So I'm a big proponent of sequencing everything
and figuring out what's there
so we can at least understand what we're losing.
Kelly: All right.
Well, I just realized what time it was,
and we have already gone our 15 minutes over,
so that's gonna be the last question for this evening.
But folks, if you had a question that we did not get to,
I will look at it along with our staff here
and we will consult with Sarah as necessary to see
if we can't answer some more of those questions for you,
and when we get that accomplished,
we'll then send an email out to everyone
who participated with those responses.
And I know you've probably heard that before,
but we actually do it.
So you will get some kind of follow-up from us with,
'cause I can see a ton of questions there
that I know we can answer for you all,
and we'd like to do that as much as possible.
As a reminder, for those of you who are educators,
we have those two activities and a diagram
in the handout panel.
Download them now or forever hold your peace,
but if you didn't get them or it didn't work for you,
please email me at flowergarden@noaa.gov
and I'd be happy to send them to you,
or you can find them, at least the two Flower Gardens ones
are available on our website on the teacher page there.
That concludes our presentation for this evening,
thank you so much, Sarah, for your patience and time
in answering all those questions.
Thank you, everyone who participated,
for all of the great questions.
It's good to hear that you were really listening
to what she had to say and are very curious
about all different aspects, as are we,
because as Sarah mentioned, there's so much
we still don't know about coral and coral spawning,
even though many of us have worked at it
for a long, long time.
Thank you, everyone, for joining us, and we hope to see you
at the next Seaside Chat next Wednesday,
we'll be talking about the future of fisheries
in the Gulf of Mexico.
Thank you and have a great evening.