Hello everyone, thank you for joining,
and welcome to another edition of the US
Geological Survey Public Lecture series.
My name is Amelia and I will be
your host and moderator today.
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On April 27th at 6:00 PM Pacific Time,
we will have Jonathan Godt.
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for natural hazards and he is also the
USGS Landslides Hazards Program coordinator.
His talk is tentatively
titled Gravity Never Sleeps,
Landslide Science and Risk Reduction.
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And now I'd like to introduce to
you our speaker for this month,
Doctor Ilsa Kuffner.
She is a research marine biologist who
has been with the USGS for 20 years
and is part of the Saint Petersburg
Coastal and Marine Science Center in St.
Petersburg,
FL.
Her love of science came at a very
early age age, as a child and with
memories of exploring the Great
Lakes and the rivers of the Midwest.
She had her first swim in saltwater
on a coral reef at the age of 17.
After that, she was hooked.
She has received her undergraduate
degree at the University of New Hampshire
and her PhD at the University of Hawaii.
Her expertise is investigating the causes
and effects of coral reef degradation.
So,
without further ado,
let's give a whirl a warm,
virtual welcome to Elsa.
The floor is now yours.
Thank you, Amelia.
Can everyone hear me? We can
hear you. You're good to go, OK?
Thank you everyone for the opportunity
to share my science with you tonight.
I'm happy to be here today.
My talk is going to be in three parts.
1st, I'm going to talk about why coral
reefs around the world are in trouble and
then I'm going to talk about how there's,
I think there's some hope for these
threatened ecosystems and I will share some
results from a genetic rescue experiment.
And then I'll talk a little bit
about the success, what a successful.
Coral reef restoration could look like.
I don't seem to be able to advance my slides.
That's OK. There we go.
OK. Sorry. OK. So the USGS,
first a bit about us is the is the science
agency of the Department of Interior.
And a quote from our director,
David Applegate is we do science
that matters to the American people.
USGS is grouped into 5 mission areas,
but of course there's a lot
of collaboration among them.
And my program is nested within
the Natural Hazards Mission area.
But I also get some support and
there's quite a lot of collaboration.
With the Ecosystems mission area
and my talk kind of highlights the
connection between ecosystem health
and risk related to natural hazards
and in this case mainly hurricanes.
Another quote from our director is
that partnerships are our superpower
and in particular my team has worked
really closely with the National
Park Service for over the last 20
years and we're honored to work
with them to achieve their mission.
Of protecting and conserving
our nation's natural resources.
Other key stakeholders that I work
with include the state of Florida,
the NOAA Florida Keys National
Marine Sanctuary,
as well as the US Virgin
Islands and Puerto Rico.
So this is a photograph showing Floridians
looking at their damaged home and Isla
Mirada after Hurricane Irma in 2017.
So a lot of hurricane damage
of course comes from wind,
but even more so when the ocean
ends up in your living room.
And this is called inundation.
So when storm surge combines with waves,
you can get a lot of damage,
but thriving reefs can actually
help mitigate this damage.
Because reefs form underwater
ramparts that slow and decrease wave
energy as the waves reach the shore,
and thus coral reefs are very
important in protecting coastlines.
So our science on coral reefs focuses
on understanding the hazards to
coastal communities presented by coral
reef degradation because as reefs
degrade the lives and infrastructure
and economies on the coasts.
Are increasingly at risks.
So what is coral reef degradation?
So this is a USGS time series by
a researcher named Gene Shinn
who's now retired,
and he started photographing the
Florida Keys reefs over 60 years ago.
So this is 1960 up in the left corner,
and you can see a thriving coral reef with
many giant boulder corals and brain corals.
Here's about 10 years later.
In 1971 you can see some
staghorn coral growing here and
still the big boulder corals.
But then starting in the 1980s we that
we started to see a lot of degradation
or loss of those live corals.
So you can see most of the coral
surrounding that big coral is dead
and the coral is much diminished.
And then here in 1998 the same Petro reef
showing almost no live coral at all and.
Basically the the bottom of the ocean
is covered with with algae and sea fans.
So what used to be reforming corals
have slowly been replaced by non
calcifying fleshy algae and soft
corals that do not produce that
rock like sea fans and sea whips.
So the coral reef crisis is really
is is symbolized by this loss,
this shift from calcifying organisms
that are habitat forming on the left
picture to a scenario where the reefs are
dominated by this fleshy non calcifying
organisms and this produces flatter reefs
that are that decline in their delivery.
The ecosystem services that I mentioned,
like Shoreline Protection,
but also food security
from fisheries and tourism.
And so why is this happening?
Why are reefs in trouble?
So here's my interpretation of the scientific
consensus on the top five stressors
causing coral reef ecosystem degradation,
and I highlight here and we'll explain
the top two global climate change.
and coral disease.
But there are others that are also important,
like overfishing and land use
change and nutrient pollution.
And but these are more localized and
and can be important in certain places.
One thing I'd like to point out is
that there's two components to global
climate change that impact reefs.
One is ocean warming and the
other is ocean acidification.
I'm not going to have time to go
into ocean acidification tonight,
but I do want to point out that ocean
warming is the primary issue because.
It causes coral bleaching,
which leads to coral death and coral
and and ocean acidification on the other
hand doesn't cause coral mortality per se,
but it does decrease the amount.
That or the the rate at which
corals can calcify and build reefs.
And it also can increase the
rate of reef erosion,
which is important when you talk about
the physical resilience of the reef.
So first, the global climate change.
This is the Keeling curve,
which are observational data showing
the the atmospheric pressure of carbon
dioxide in the atmosphere at Mauna
Loa Observatory in Hawaii since 1960.
And you can see that it's going up. And.
What's happening in as a result of that
is with more CO2 in the atmosphere,
we get warmer atmospheric temperature.
This is, these are observational data
or measurements. Looking at this,
the temperature at the Earth's surface,
including the oceans.
And as you can see,
the the nine years between 2013 and
2021 rank among the ten warmest
years of the instrumental.
Record.
So what does ocean warming
look like on coral reefs?
And this is is an example of some data from
the Florida Keys that I published in 2015.
And these were historic,
comparing historic data that
were taken by lighthouse keepers.
These are lighthouses off the Florida Keys,
and they're about 10 miles from the shore,
and lighthouse keepers
used to live out there.
To turn on the lamps, um and.
TW Vaughn, who was actually a USGS
employee at the turn of the century,
commissioned the Lighthouse board to get
their lighthouse keepers to record daily,
daily ocean temperature by
throwing a bucket over the rail,
pulling it up and sticking
a thermometer in it.
And I found these data,
and I compared them to data.
So once the light keepers were gone in 1990,
Noah put automated sensors on
the legs of these structures.
So we had ocean.
Temperature for two decades back
in the 1800s and then we have ocean
temperature from recent decades.
And so the graph that you're seeing here.
So the Y axis is temperature
and the X axis is month,
so January to December.
So winter,
summer,
winter and the black bars are
the average temperatures from
that two decade period that was
100 years ago and the Gray bars.
Are the temperature averages
from the recent decades.
And So what you can see is that
the the Gray bars are first of all
all higher than the black bars.
And what's most significant for coral
reefs is that these three summer months,
so this is July,
August and September.
This this box,
these boxes are shaded red
because that is the temperature
above 29 degrees or about 85.
Degrees Fahrenheit that can
cause coral bleaching.
And so I'll explain what that is.
So coral bleaching is the breakdown of
the symbiosis between coral and their
algae that live inside their tissues.
Corals are very complicated animals,
believe it or not.
They are a colony of connected
polyps like sea and like tiny
little sea and enemies.
And here's the inset photo.
You can see a coral polyp.
And they have.
Symbiosis with these single celled
dinoflagellates called zooxanthellae
which you can see here in the up close
microscope picture and there's no sense.
So this is a a mutualism where
the zooxanthellae get a nice place
to live with a steady supply of
certain nutrients and in turn the
zooxanthellae supply the corals
with the sugars that they make
from photosynthesis as food.
And so this is a great mutualism,
but it is it breaks down in
higher than normal temperatures,
and if weeks go by the coral can die.
So basically it starves to death
because it doesn't have that
that source of food.
And even if it does survive
while the coral is bleached,
it the calcification rate or the the
production of its skeletons stops and
the reproduction completely stops.
And so here on the left.
You can see what a normal coral
looks like in normal temperatures.
It has a nice population of these
zooxanthellae living inside its tissues,
and then when the temperature gets
above about 85 degrees Fahrenheit,
the zooxanthellae get kicked out.
And what you see,
the reason it looks white is because
all the color is imparted by the
zooxanthellae and once they're gone,
all you see is the bright white skeleton
shining through the clear tissue.
So coral disease is the other
major problem right now.
In recent decades,
that has caused a lot of coral mortality.
And this is a time series of the
same coral this these photographs
were taken in Biscayne National
Park off of Miami in 2015 and 2016.
Same coral a year later left one shows it
infected with this disease and a year.
Later, it was completely dead.
You can see these two Christmas tree
worms in the same place in the colony,
just showing you that it's
it's indeed the same colony.
And Stony coral tissue loss disease
is a really virulent disease that
affects over 20 species of corals
and but there's been other diseases
that have been equally as bad
that affect only a few species.
And this is just a quick slide to
show you some more disease impacts
that I documented in my work.
These this is the a species of
brain coral 1 coral here you can
see survived the disease and this
guy completely succumbed to it.
He's got one little patch of tissue
right there and this is from Buck
Island Reef National Monument in Saint
Croix and so the majority of this.
Species of brain coral has been wiped out,
probably about 75% of some populations.
But the exciting part,
and this is where I tried to try to
get into the hope part of my talk,
is that not all of them have died,
so some have survived and this
is significant.
So this brings me to the next
part of my talk,
which is the hope I mentioned and the
fact that in chaos there is opportunity
and reefs have persisted in some form
or another since the Silurian period
that's over 400 million years ago.
And this is a photograph of a
reef in Florida after Hurricane
Irma just to to demonstrate that
disturbance events happen on reefs.
Reefs are are.
Are adapted to dealing with hurricanes,
but the disease and the temperature
stress seemed to be coming at
rates that they haven't experienced
in a really long time to to our
knowledge anyway and but these,
these,
these disturbance events can also
be opportunity for population
and community reassembly.
And so this is a slide to point
out the role of disturbance
in the process of evolution.
So there's two main theories
as to how evolution proceeds.
On the left, evolution is depicted
by happening continually and this
is known as phyletic gradualism,
where one species slowly
evolves into the next overtime.
And then on the right,
this model is called punctuated equilibrium.
Showing evolutionary events
where new species pop up closely
or quickly and and in response
usually to disturbance events.
So there is fossil evidence
for both of these mechanisms.
But my main point in this slide is that
evolution is not necessarily a slow
process and it can happen arguably
with greater effect very quickly in
response to disturbance and this
can include rapid climate change.
Disease epidemics et cetera,
and these events cause evolution by
through the process of natural selection,
which is basically after disturbance event.
Whoever is left alive to reproduce then
passes their genes on to subsequent
generations and you can get a very,
very quick change in the population.
So this one slide summarizes very
well why I have optimism about corals
and why I think these ecosystems
could survive this century and why I
think humans might be able to help.
So these are two corals of
the exact same species,
this is the mustard hill coral,
and they're experiencing the same
environment, the same temperature,
the same nutrients,
the same everything about their environment,
but one is completely bleached.
Here on the right,
and it's starving to death, and it has
none of its algal symbionts anymore.
And this one here is
apparently completely healthy,
it has all of its zooxanthellae
And So what in the world is
causing this disparity?
And so the hope here is that this
that there's a considerable amount
of heterogeneity in the response
to stress apparent on reefs today,
and this suggests that there's
enough genetic diversity.
Remaining in the population for
natural selection to act upon,
and thus humans might be able to
help through reef restoration,
so restoration could help.
Coral reefs bridge this gap
between now and when CO2 and
temperature increases level off,
either because we run out of them or
we we mitigate fossil fuel emissions.
So what is coral restoration?
20 years ago, no one had really
heard of coral restoration,
and those that did kind of marginalized it,
they said it was too hard, too expensive,
too difficult to scale up to the point
of making a real difference for reefs.
And there was a lot of focus back
then on marine protected areas.
And scientists did show that marine protected
areas increased fish stocks and increased.
The biomass of fish.
But what we were also hoping to see from
MPA's is that it made life better for corals.
But it didn't. Corals kept dying
and kept disappearing from reefs.
So this led people from mainly the aquarium
industry and nonprofit conservation
organizations to start coral farming,
to start restoring reefs.
And so this was first done in Florida,
this kind of ground.
Zero for coral reef degradation in
a lot of ways and but over this,
the last two decades the scientific
community has really come to the
consensus that it's time for
bolder interventions to save reefs
and that includes restoration.
So what you're looking at here is
this is an offshore coral nursery
established by the Coral Restoration
Foundation and these are other agencies
that are involved in restoration
and and what they do is they.
They take cuttings of corals,
very similar to what people do with plants,
and they grow them out on these trees
offshore and they'll increase in size
and grow really fast and and then a
year or two later they'll take those
corals off of these trees and plant
them on a reef and start new colonies.
And so USGS's role in this is to
conduct science to help guide
restoration strategies for our partners.
And so the next part of my talk is
talking about capitalizing on this hope
and our science to guide restoration.
And one of these the ways that we
do this is through what we've called
the calcification assessment network.
And so since 2009,
we've been directly measuring
calcification rates of coral in the
field and this is a new approach to
coral reef monitoring or assessing
their health and so traditionally.
People trying to figure out if MPA's
were doing any good for corals used to
for photography based approach where
you visit a site with you scuba dive,
you take pictures of the reef and
you measure what percentage of the
sea floor is covered by coral,
algae and other benthic living organisms.
And so our work adds to that
toolbox because it moves beyond this
percent cover approach.
And actually quantifies coral
calcification or the amount of
calcium carbonate skeleton added by
the coral in a given amount of time
in a given amount of space.
And calcification is a fundamental
process to coral growth of course,
but also reef accretion.
And so it's essential to this process
of to it's an essential process to to
providing or delivering the ecosystem
services that I mentioned such as shoreline.
Protection.
And so now we're quantifying the
spatial patterns in coral growth
along environmental gradients and
through natural stress events
with multiple species of coral.
And how in the world do we do this?
Well, we have a very simple approach,
excuse me, where we basically glue corals
to these discs and the discs have a
bolt coming through the bottom of them.
And these are our calcification assessment
stations where these are secured to the
bottom with stainless steel threaded rod
that's drilled and epoxied into the reef.
So these don't go anywhere during
hurricanes and we wing nut the corals
onto these onto these cement blocks
to grow and then we measure them over
time using the buoyant weight method.
And so basically this is
a simple application.
Of Archimedes principle where you can
measure the weight of an object in
air or you can calculate the weight
of an object in air by knowing its
weight in water and then adding
the weight of the water displaced.
So you can easily calculate the
dry mass gained each time you
buoyantly weight weigh the coral.
And this allows for very precise measurements
of the amount of skeleton added.
And this is this is kind of the.
Procedure that you're basically
hanging the coral in a bucket of water.
So over the past two decades,
we've looked at 5 species of
coral and published the results.
And you know, these are the first
calcification rates measured directly in
the field rather than retrospectively
by looking at the skeletons,
umm, and, you know,
killing a quarrel to look at
how much it it gained.
And So what we've found is that there
are spatial and seasonal and species
specific patterns and calcification,
but kind of the most.
Exciting result is that we've seen that
four out of the five species we've looked
at calcify faster in the Dry Tortugas.
So these these yellow stars are
sites where we've had calcification
on network stations and they so most
of them calcify faster in the Dry
Tortugas National Park compared to the
main key sites except for this one
coral that did pretty well in Biscayne
National Park, but I'll come back.
That in a minute so um species
specific differences are also marketed.
So here this is the staghorn coral or sorry,
Elkhorn coral, staghorn coral.
These are the two threatened
species of coral. And.
In kilograms per meter squared per year.
So this is kind of like a like
a square yard and a kilogram.
So.
So this is 30 kilograms of of skeletal
mass that this coral is growing per
year in a meter squared and this is
kind of a a visual aid for what 66
pounds looks like and this is a well
stocked beverage refrigerator so.
It's a,
it's an incredible amount of rock
that these corals can produce in in a
year and Elkhorn corals and its congener,
a staghorn corals build reef really fast.
And so this one in particular is the
Elkhorn coral and I'm going to focus on
that species for the rest of my talk,
so.
The Elkhorn coral is the most
important species in the western
Atlantic for shoreline protection
because it's the only species
that creates the reef Crest zone,
which is where the waves crash.
And so that's where you get that rampart
effect or that wave dampening effect.
And this photo is showing the
species growing as it used to.
Decades ago, this was in the Bahamas.
It was a nice outcrop that was left.
Doing pretty well and these
colonies get huge.
They are like 10 feet high,
20 feet long,
kind of the size of city buses or train cars.
Here's another photo just showing
you this impressive species.
Um this photos from 1970 at Buck Island
Reef National Monument in Saint Croix.
And unfortunately these reefs and
most like it are largely dead from
a disease epidemic that happened
in the 1970s and early 80s called
white band disease.
And then later from bleaching there
was quite a lot more mortality so
populations were greatly reduced
and disappeared.
Completely in some locations.
And they've failed to recover
since that time,
despite marine protected areas
and despite all kinds of other
management actions.
So that led to the this species
of coral being
the first listed under the
Endangered Species Act.
So that leads to where we are
now and I'm going to share you
share with you the results of our
genetic rescue experiment that we
did in Dry Tortugas National Park.
Umm, just a quick detour to
tell you about the Tortugas.
They're here at the end
of the Florida reef track.
It's a very well studied area
because of the Carnegie institution
had the Tortugas Marine Lab
operating between 1905 and 1939.
Um, what you see in this inset
picture is Fort Jefferson,
which is a civil War era Fort that's
basically built on a sand spit
out in the middle of the ocean.
If you get a chance to go to this
National Park, it's one of my favorites.
It's just absolutely stunning.
But so this this colony of what
you see here in the picture here,
so there is some Elkhorn coral that is
growing wild in dry Tortugas National Park.
But in 2015 we found through genetic
testing that all of the colonies and
this covers almost an acre are of 1
genetic clone meaning they can only
reproduce through fragmentation.
And I'll I'll talk a little bit
more about that in a minute.
So first.
We we set out to do an experiment to
advise the park on whether managed
relocation and restoration of this is.
This threatened coral species would work.
So our experimental design was to
relocate coral fragments from a
nursery that was roughly around here.
That was the Coral Restoration Foundation.
Our partner and we were given 5
unique genetic strains from them
and we brought replicate corals
from their nursery and place them
or translocated them to these
five sites all the way from Miami.
So these are all offshore reef sites,
Crocker reef down to sombrero and
then two sites in the Dry Tortugas.
And so our questions.
Were can Elkhorn coral transplant in
300 kilometers away survive and grow?
Will corals do better at some
sites than others?
And will some genetic strains grow
better in some places than others,
or better than just better in general?
So our results were pretty clear cut.
All of the coral fragments moved to Dry
Tortugas did fantastic and this didn't
matter what genetic strain they were.
And but the same genetic strains
brought to the northern Keys and
the middle keys did not do as well.
So what you're seeing here in this inset
picture is a time series photograph.
So this is spring 2018.
All the corals started out the same size,
like around the size of a chicken nugget and.
And then we left them to grow.
We measured them every six
months and took pictures of them.
And and so this coral,
these corals started out there,
the same genetic strain.
But the one that was brought to
Dry Tortugas here you can see was
nearly as size of a dinner plate
by the end of 18 months.
And the other one was barely bigger
than the disk that we put on.
And so that was the pattern that
we saw with all the corals and
so basically we answered.
More questions.
Yes, these these corals have brought
from the northern Keys will grow
absolutely great in Direct Tortugas.
Yes,
there are sites that are better
than others and that's the two
in the drive through two goes.
So this goes from West West to east.
So these are the two dry Tortugas sites
and X axis is calcification rate here
it's broken down into the coral strain.
So the different colors and symbols is the
different genetic strains that we tested.
So you can see.
This West East kind of gradient,
um.
And then there also was a
subtle genetic effect.
So I don't know if you can see this too well,
but like the two red dots are close together
here and they're two there and there.
So you see they kind of pair with their,
with their clone mate in their
response to being moved.
So that was really interesting too.
We didn't really expect to be
able to see that genetic effect,
but that points back to that
hope that there's enough.
Genetic variance in the wild populations
for for natural selection to act upon.
So, uh, then this is an example
of some serendipity in science.
This experiment had to be ended,
had to be ended six months
early because of COVID.
So, you know, we we had our
our last time period planned,
but then we couldn't go because
of the travel restrictions,
and we didn't get back to our corals
for a full year after we had seen them.
And during that time they had
completely overgrown the blocks
in Dry Tortugas and and and so you
know our experiment was a success.
We went ahead and had clear enough
results to publish just the 1st 18
months of it and that was great.
But an unexpected outcome because we
couldn't get back to them was that
the corals claimed their blocks and
and so there was no way to remove
them and so this resulted in the
accidental establishment of what
we are now calling a spawning.
Orchard and so.
But first I have to explain what
what coral spawning is so corals
can reproduce in two ways.
One is vegetative fragmentation or
asexual budding and this happens a
lot during hurricanes when a colony
will be broken and then it can
really you know stumble along on
the bottom and and find a crevice
and and just get caught there
and start growing again.
But this type of reproduction.
Doesn't allow for adaptation because
all of the daughter colonies are clones.
And then there's sexual reproduction
or spawning,
and this is an annual event where
corals release their gametes
all-in-one synchronized event.
They create these buoyant egg sperm
bundles that are positively buoyant
and they float to the surface of
the water and form this slick,
and that's where fertilization occurs.
But the gametes must not be
from the same colony.
Umm that that they cannot be clones.
And so Elkhorn,
like most reef building
corals are hermaphrodites.
So they produce both eggs and sperm,
but they cannot sell,
fertilize and and so umm but
any if they do fertilize,
if there's two different clones available
and they they mix and they fertilize,
then what is it that the gametes form into
develop into a forming embryo which.
Develops into a free swimming larva here,
and this is about 1/2 a millimeter
long and they're capable of swimming.
They have cilia and this species
carries its zooxanthellae with it.
That's where all the polka dots are in
the in within that little coral larva.
And so these guys swim around in
the plankton until they find a good
spot to settle on the sea floor,
and then they start a new baby coral colony.
So here is just a picture of coral
spawning what it looks like when
they release their egg sperm bundles.
And here's the coral a picture
of coral recruits once they've
metamorphosed onto a hard surface.
And so here's the last part of my talk,
and this is is some thoughts on what
successful restoration would look like.
And successful restoration would
help corals reproduce sexually again.
And so why is getting corals to sexually
reproduce again key to restoration success?
Well, because the ocean is changing,
it's warming, it's becoming more acidic,
and the recombination of genetic
material is necessary for corals to
adapt to these changing conditions.
So one explanation for why sexual reproduction
has become so rare and difficult in this
species and others like it that are
threatened is called the allee effect,
where corals of different genetic
strains are just too far apart for
their gametes to mix during spawning,
and so they produce no viable
larvae if they are spawning.
And so reproduction or sorry so restoration
if completed with genetic diversity in mind.
Could alleviate this Allee effect,
allowing to allowing corals to live close
enough to sexually reproduce again.
And so that's the idea behind
these spawning orchards and that
there is an opportunity for corals
to reproduce naturally,
but they also could be used as
sites for assisted reproduction.
But I'm not going to go into
too much detail about that.
And so this is just showing that
these two colonies that overtook our
blacks are now thriving and they.
We're living within a couple meters of uh.
There's six genetic clones within a
very small radius where they can mix.
So successful restoration,
excuse me.
Restoration would also connect reefs
and the larval phase as I showed you.
Here is the mode of transport for
coral species that allows them to
colonize new areas and the plant.
The planula can swim in the plankton
for months and the record was set
by my lab mate in grad school.
He reared one for 350 days.
Umm,
so they can live for quite a
while in the plankton.
And um,
So what do I mean by
connecting the black dot?
Here is Dry Tortugas National Park placed
on a map of the prevailing ocean currents
which you can see the Yucatan current,
the loop current.
Which hooks into the Florida Straits
and becomes the Gulf Stream and uh,
these these currents,
these ocean currents are extremely dynamic.
But in general you can see that Dry
Tortugas is is both on the giving end
and the receiving end of these currents.
And so larvae that were
spawned in Dry Tortugas,
if there was to be a a restored
spawning population could potentially
reseed the rest of the the
downstream northern Florida Keys.
So not only are corals calcifying
faster in Dry Tortugas,
but the but a restored population there
would be well connected to downstream,
downstream reefs.
So lastly,
uh restoration for ecosystem
recovery would connect reef awasis.
And what this is what we call in
this paper that I wrote with some
some colleagues is what we refer to
as pockets of reef that are still
doing better than their neighbors,
looking better than expected
given all of the stresses they've
experienced and this paper focuses on.
How to predict where we can find them?
Because to connect these reefs
we first have to find them and or
create them through restoration
if there aren't any left.
So you know,
finding places where ecosystem
functions are still viable and
conditions are favorable in helping
them reproduce on their own.
Or even intervene through
assisted reproduction.
This could result in an opportunity to for
corals to evolve to changing conditions
faster than they could without our help.
And so that concludes my talk and I
just want to acknowledge my whole
team and all my collaborators.
It wouldn't be possible to do all
this work without a whole bunch of
people and and the support that I get.
And I do want to also acknowledge
that I love my job.
I feel so fortunate to have the
opportunity to do the work that I do.
And so thanks for listening and
I hope to answer some questions.
That was fantastic.
Ilsa, thank you so much.
I learned a great deal myself
today because it was just cool.
So cool to hear how you,
how new corals are formed and
colonies and just kind of seeing all
that research that you're doing.
Just fantastic. Yeah.
So just to remind everyone,
we have reached our portion
of the Q and A session.
And if you do want to ask a questions,
feel free to click on the Q and A icon
on the upper right hand corner and
go ahead and ask your question.
We do have several questions
here that I'm going to read off
to you that I've come through.
And let's start off with the first one.
We had one really early in the talk.
They had asked, uh,
what coral reef is in crisis,
and I think you covered a great deal of that.
But I think it's kind of tied
into another question that kind
of came in that they're wondering,
do you find more coral issues in
some oceans more than others?
Are they dying in certain areas,
for example,
issues of the Atlantic versus
versus the Pacific?
That's a great question,
so.
One of the,
one of the things that's very
different about the Atlantic
compared to the Pacific Ocean is
the the diversity in corals at all.
Like there's about 60 species of corals,
you know throughout the entire Atlantic,
but there's hundreds in the Pacific
and so reef degradation has happened
faster and and and kind of more.
Clearly, in most of the western Atlantic,
because of that,
there's not a lot of redundancy.
If one species is having a hard time,
there's not five other species that kind
of live in that same niche to fill it.
And so the Atlantic is kind of at a
disadvantage when it comes to that.
But it's a great question.
And and you know the Pacific used
to think that they weren't going
to be seeing coral diseases,
but then all of a sudden now they do.
So I think the same global
stressors are happening,
definitely coral bleaching.
We've seen that all over the world.
Global coral bleaching events
are happening more and more.
So the Atlantic might be a little ahead,
but the Pacific is also the Pacific reefs
are also having the same difficulties.
All right, thank you for that.
Jamie asks.
What would you equate the reassembly
of coral to a controlled fire on
land to then replenish the soil?
Hmm, that's a good question.
Well. I think uh,
like a a fire climax community.
Like they've evolved to have disturbance
events like fires where you know seeds
like plants have evolved to have
certain seeds that only that only
break and sprout after after fire.
We, I don't, we don't see like that.
Same sort of mechanism in the
ocean hurricanes is probably
the best analogy with fire.
Because it is a natural disturbance event,
um, that you know corals
have evolved to experience.
You know they've experienced for.
You know, as long as they've been around.
Um, so.
I mean there are there are certainly
species of coral that are early
successional species like weedy and
have evolved different reproductive.
Strategies and so yes we we do see that
there's like an early succession after
disturbance we get a lot of small brooding
corals that that internally fertilize
them and and brewed their larvae.
So. So yes the answer is yes it is
similar in some ways. OK, great.
Carl wants to know what causes the
breakdown of the coral calcification
when the coral dies?
When the coral dies, well, so the coral.
The coral creates rock by combining calcium
ions with with carbonate ions and umm.
And it precipitates this with
the help of its zooxanthellae
And there's a lot of complicated chemistry
that goes on within the coral's tissues,
but basically as core as corals,
calcium as the zooxanthellae photosynthesize,
they train.
They changed the chemistry inside
the coral and help it.
Help it um precipitate the skeleton
and with so when bleaching happens
all those zooxanthellae are gone and
the coral starving because it it
actually takes a lot of energy to
calcify as well and and so it stops
calcifying when it's bleaching but then
when it dies it completely stops you
know there's there's no live tissue
there's no Organism there at all to
be precipitating the the skeleton.
OK.
Someone is asking if the genetic diversity
is as or more important than human diversity.
I guess you're wondering about
inbreeding issues as a comparison.
That's a really good question,
and that's one of the reasons why
there's there's a huge community
of geneticists that are bringing
their expertise to these issues.
I'm actually part of a review paper.
That's being put together right now
and so I'm not a geneticist but but
what but it's very important yes to
have a a genetic management plan when
you're planning to restore reefs
because you don't want siblings to
be mating with other siblings and
things like that.
Just like in human you know in in the
human system and outbreeding is much better.
So you know that's why these large.
Translocation type of experiments are
important to do just to make sure
that it's going to work before we advise.
But you know,
the longer the distance apart is usually
the longer distance genetically also.
So yeah,
the you know when you have these
remnant populations you want to
gather as much diversity as possible.
OK, great.
Francisco had the kind of a two parter question.
I'm going to ask one at a time.
He was wondering if any relation to
where the coral reef is on the edge
that the location of the reef has
any relation to tectonic plates.
Um.
Well, I mean,
coral corals of different species have
different requirements for habitat.
So there's some species that are so
Hardy that they can live in little pools of,
you know,
like pools of hot water,
but but most like a very offshore area.
They also require hard substratum.
So like they can't,
they can't settle on the sand.
Um, they can't settle on the
rubble that's being rolled around
a lot because they, you know,
once they pick a spot to settle,
they've got to stay there.
I mean they're,
they're sessile organisms.
So I'm not sure I mean like about the as far
as the tectonic plates and things I I think.
You know the where where volcanism
is actually happening,
you can get fresh lava flows and you
know like in Hawaii it does take a
long time for corals to collimate
volcanic flows just kind of because
you know it's the same as plants.
It's just not really ready yet
to to have things growing on it.
But yeah, I hope I answered that question OK,
OK.
He also wanted to know what percent
of the polyps form reproduction,
reproduction versus sexual reproduction?
That's a good question.
So the asexual fragmentation can
happen with any chunk of the coral.
You know,
you can take a piece off the the the
trunk on the bottom or the very tip and
it'll it'll vegetatively grow just fine.
We we do find that the the very
tips of the growth edges of
the Elkhorn coral at least and
and the staghorn coral also.
They're very focused.
On producing skeleton and so probably
would not have reproductive polyps
so and I've I've seen coral spawning
and with the Elkhorn coral you know
it's it's pretty amazing though
the coverage like all through I
mean it releases all its eggs per
bundles at the same time and so
it's like an underwater Blizzard you
know it looks like it's snowing in
reverse and it's it's a good part
of the colony that that usually is.
Releasing the egg sperm bundles,
except for maybe the tips.
OK. Jamie wants to know.
He has several questions,
but I'll kind of break break
those down a little bit.
But he wanted to know how long in your
research does it take for coral to
adapt to temperature change in the water?
So that's a good question.
Um, there there is a certain amount of.
Basically there's a threshold that
anything above about 85 degrees,
they're just not going to adapt to,
or I should say acclimate too.
But if you look at where coral reefs
are distributed throughout the world,
we do see that over evolutionary timescales,
corals have evolved to live in in higher
temperature areas like the Red Sea,
which can get all the way up
to like 90 degrees.
In the summer, so, um, there,
that's also a source of hope that,
you know, if you look over long,
you know, generational time periods,
multiple generations,
you can get adaptation for corals
to tolerate higher temperatures.
But as an individual coral, they're kind of.
You you can try to ramp them up but.
They're they're they're just
gonna cook when you get past
their their temperature that they
have evolved to live in,
OK. He also wants to know, does one type
of coral reproduce faster than others?
If so, can these types of coral
be placed by humans in order to
curb the effect of climate change?
Very good question, um.
Yes, there are a.
Corals are very creative when it comes
to sexual reproduction strategies.
There are some species that have
separate males and females that still
manage to spawn all at the same time.
Umm. But as you can imagine there,
you know it's it's tough because
you might have a whole reef with
just males and no female and so,
so those are probably bad
candidates as far as.
Trying to get them to reproduce on their own,
like those species will probably
need need more assisted reproduction.
And then there's others that are weedy
and we'll produce larvae all year long.
And those are the brooding
species that I mentioned.
But unfortunately, most of the
brooding species tend to be small,
so, you know, like golf ball size,
so they're not exactly growing
reefs and protecting shorelines.
So, so far I haven't heard of a brooding.
Massive coral?
Um,
that would would really be a good candidate.
Good question.
Yeah, no,
we're getting a lots of good
questions here from everyone.
Patrick wants to know why were
the dry Tortuga sites so much more
successful than the sites to the east.
I was hoping somebody was going to ask that.
So I have some unpublished research
that I'm really excited about,
excited about.
It was collaboration with the
Ohio State University,
Andrea Grotowski and Leila Chapran and
we're we're just about to publish it.
So I can't really show you the
results yet that I can verbally
tell you that and so their their
expertise is looking at basically
like the same as humans.
When you go in to get your blood work done,
you can do that to coral,
you can look at their levels of
cholesterol and sterols and fatty
acids and basically look at all of
the the the health metrics that
we look at when when we go to the
doctor and what they found in.
Sampling all of our corals is that
the ones in Dry Tortugas have
evidence that they are eating more,
that they have more more evidence
of heterotrophic feeding.
So I didn't really mention this in my talk,
but corals are also predators.
They have stinging cells on the
ends of their tentacles and they
capture zooplankton and and food
from the water column,
and that's how they get their
nitrogen to feed the zooxanthellae
And so when corals feed more,
they are more resilient to
temperature stress,
to diseases and they're just
in general fatter,
happier and more resistant to
to all kinds of stress.
So that's what our new research
shows is that the corals in Dry
Tortugas are getting more food
and we think that's because of
the ocean currents that will spin.
They spin up these eddies that basically
result in upwelling events where.
Nutrient rich water will come up onto
the platform and that and that generates
a bunch of primary productivity or
or explosion in food for the corals.
So that that is yes, it's,
it's exciting, it's a new.
So that's a new hypothesis that we we have,
we have evidence to support.
OK, great. Because someone had asked
sort of a related question to that.
Laurie had said,
why are the Dry Tortugas so successful
for coral versus other key locations?
And I think you pretty much answered
it because I think there's more
dry Tortugas out there though,
like more dry Tortugas like places.
And you know places where you
have those dynamic ocean currents
and you know so I think,
I think we can find them but and
for example we found that our
corals in Saint Croix grew at
rates equivalent to Dry Tortugas.
So that also seems to be a really
good place for for coral growth.
You know and and we might find the right?
Genetic strains that can grow well in
the Florida Keys northern parts too.
So yeah,
it's definitely not worth giving up hope.
Right. Very cool. Umm.
Terry wanted to find out.
Are you finding reefs thriving
in previously stagnant areas
due to global warming,
much like the wind industry relocating to
Southern Oregon from Northern California?
Great question.
So there are,
there are some species of coral
that we're seeing creeping up the
coast and this is happening with
the Kuroshio Current in Japan.
There's a western current in Australia
that's showing migration of tropical
species a little bit further toward
the equator and and we also see have
seen that a little bit in the Florida
Keys and that staghorn coral have
started to grow a little bit further.
North than they used to so it's
it's tempting to you know think that
Oh well corals it can just migrate
and you know maybe that will play
a role for certain species but as
in the case of the Florida Keys
anyway they run out of habitat.
There's there's a there the the
shelf is very narrow there and the
water gets trapped it's it becomes
temperate very fast so there are limits.
But,
but yes,
we have seen some of that.
Jamie had one other question.
Do reefs provide oxygen to the planet,
or are the main benefits for humans to
provide protection to the coastlines?
I would say the latter.
Corals are there.
The chemistry of corals is actually
really complicated in that they you know,
they're skeletons.
They use CO2 to build their skeletons,
but it actually ends up being a net
source of CO2 to the atmosphere,
which is really counterintuitive
and hard to explain, but.
But generally they're they're
like on a on a human timescale.
They neither produce nor.
Consume CO2 or or oxygen,
it's it's a like a diurnal cycle
and it ends up being a net zero.
So.
So yes I would I would say shoreline
protection and habitat provision.
I mean these are these are species
that are ecosystem engineers.
So they're like the trees of a
forest you know they create habitat
that all kinds of other organisms
live in and so without those.
Foundation species.
You don't have the ecosystem. OK.
And one final question from Jess,
which I love because it's kind of a doozy,
but it just sounds so amazing.
Something to think about here.
If you were the queen of all coral
reefs and you could work with or
combine corals between nations,
what would be your dream
international experiment be?
Ohh wow, I told you it was a doozy.
That's a great question.
You know, it's a it's a very uh,
I mean there there are a lot of risks
that we need to think about when we
think about moving organisms from
1 ocean to another, but I if if.
In uh some like alternate universe
we could take away all those risks.
I would love to take some
of the Pacific a crop rids,
the Pacific Elkhorn corals
that you know they have.
They have 100 species of acropora
in the Pacific and we only have
two in the in the Caribbean.
So I would love to do that experiment
and I don't think I would ever
get the permits to do it but.
The thought is nice, isn't it?
Yeah. But that said,
we thank you so much everyone.
You know,
they've sent in feedback about
how wonderful your talk was.
They were so grateful that you answered
all of their questions and we're
very grateful to have had you today,
but that is it.
A huge thank you again to you,
Ilsa for your talk today and for taking
the time to educate us on the coral
reef restoration and what we could do.
And also thanks to all of you
out there for joining us.
In case you want to watch this again
or share this lecture with others,
ilse's lecture will be available
in about a week for on demand
viewing on our website at WWW.
Dot
usgs.gov/PLS you can also find videos of
our previous lectures that go back 20 years,
as well as our lecture schedule
for the for the rest of 2023.
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Finally, we hope you will join us
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6:00 PM Pacific Time for Jonathan
Gott's lecture on landslide hazards,
Gravity Never sleeps.
Thank you again and for joining us
and you have a wonderful evening.
Goodnight.