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Six years, 22 countries, close to 200 scientists, and one exceptional research vessel. The Global
Reef Expedition is on a mission to study coral reefs around the world.
Coral reefs are undergoing a worldwide crisis, and we are trying to understand where the
healthiest reefs remain, what sort of factors make those reefs healthy, and reefs that have
been degraded, how we can help them recover and persist into the future.
To do so, expedition scientists conduct a number of studies in the field.
We are applying a standard protocol that was developed through a consortium of scientists
and we think this will be incredibly beneficial to the world of science, and management of
resources, because now we can truly scientifically compare one reef to another, from one region
to another. We operate under this banner of "Science Without
Borders." It is basically because there are no political
boundaries between the oceans. It is all connected. And what you do in one location, can affect
another location. Every country we go to, we work with the government
agencies and whatever universities are there, to identify local participants.
And we bring them out with us, first to get them to places that they cant normally get
access to. Second to show them what we are doing. We try to provide training to them
so that they pick up some of our methods, and carry it on.
It is a two-way street because the local knowledge is immeasurably important to our research.
And then the local scientists benefit by interacting with world renowned scientists from very prominent
universities and organizations. What every single country says is that their
biggest limitation to really enacting sound conservation strategies, is lack of scientific
information. Our ultimate hope is that the research will
influence action on the ground. And so we are acting as a catalyst, we are
an accelerant to change. Major funding for this program was provided
by The Batchelor Foundation, encouraging people to preserve and protect America's underwater
resources. And by Divers Direct, inspiring the pursuit of tropical adventure scuba diving.
Tahiti, Bora Bora, the islands of French Polynesia evoke visions of an exotic, tropical paradise.
Located in the South Pacific, about halfway between South America and Australia, the island
nation is made up of five archipelagos. French Polynesia has hundreds and hundreds
of islands. And it is spread out in a massive geographical range.
It is the size of Western Europe basically. These islands, some of which have been studied
extensively, others have never been surveyed by scientists. And it is really exciting to
go research areas that you know for a fact no other human has visited, and certainly
never conducted any systematic scientific research.
We are trying to compare reefs that are in a similar region across what I call gradients
of human disturbance. And what I mean by that, is going from very populated areas to very
unpopulated areas. And it will help answer a lot of the questions
that we have about resilience and how that is related to human impacts.
The Global Reef Expedition is organized and funded by the Khaled bin Sultan Living Oceans
Foundation, a US based non-profit established by His Royal Highness Prince Khaled bin Sultan
of Saudi Arabia. Prince Khaled became a scuba diver and really
fell in love with the ocean and particularly coral reefs.
While he was diving in the Red Sea, and he had one reef that was his favorite dive. And
so he went back there a couple years later and he saw the deterioration of the coral
reef first hand. And so that really gave him the initiative to do what he could do as a
single person to try to help preserve these beautiful coral reefs.
In 2011 the Global Reef Expedition got underway in the Bahamas. Since then, a dedicated team
of researchers has worked its way across the Caribbean, the Galapagos, and to the South
Pacific. In each location, science divers conduct a
rapid environmental assessment to collect baseline data.
We want to know what corals are there, what fish are there, what the bottom looks like,
what other types of organisms are found there. Right now we are on Rangiroa, which is the
largest atoll in French Polynesia. And there is about 450 different atolls around the world.
And French Polynesia has more than any other country. They have about 85 of them.
Atolls are ring-shaped coral reef islands that surround a lagoon.
On these atolls, we look inside the lagoon, and we look outside the lagoon on the fore-reef.
At each site, the divers work in a 100 square meter area. Dive buddy teams collect different
types of data. One team collects information on fish.
We lay a 30 meter transect line. This is attached to us as we swim along the reefs.
As the divers work their way along their transect lines, they identify and count all of the
fish species they see within a four meter radius.
We try to do as many as we can. Typically we would be able to cover maybe four transects
during one dive. Around Rangiroa, we find a lot of sharks,
which is typical for the area. At the same time we also find a lot of herbivores, such
as surgeonfishes, and rabbitfishes, or parrotfishes. These species occur in large schools that
swim around the reef. And they are also very significant in they have important roles on
the reef. Another team of divers is conducting benthic
surveys, which means they are studying what lives on the sea floor.
I lay out a ten meter long transect line, and every ten centimeters I record what is
directly underneath that point. And I do this to accurately record what is on the bottom
of the reef. And that helps us determine how much of it is coral, how much of it is sand,
how much of it is algae. And then we do this at different depths, at every single reef,
multiple times. And then that really helps us to assess what each reef looks like.
And then the third survey approach focuses specifically on the corals. And we again use
a transect. We lay out a line that is ten meters long and we assess every coral that
is within one meter of that of that line. So we are looking at a ten square meter area.
And for all these corals we will identify what type of coral it is, we then measure
its size, and then we record information on how healthy that coral is.
By measuring size, it gives you information on the current status of that reef, the past
history of the reef, and the direction it is likely to go in the future.
And so an ideal reef would be one that has a lot of different species together, and it
also has a wide range of sizes. Other divers conduct what are called photo-transects.
To do so, they use a one square meter quadrat made from PVC pipes.
And we will put that quadrat down and we just flip that over ten times and take ten pictures.
Because we are limited on time you can only do so many belt transects in there. We get
the same information from these quadrats. We can get cover and we can get size of the
corals. The reason we collect all this data is because
the more you know about the reef, the better you can manage the reef.
We know that one of the major factors responsible for the global coral reef crisis is climate
change. Sea water is getting hotter than it has ever
been before. And so it is causing corals to bleach and die. Storms are getting more intense,
there is a growing threat from where the oceans are getting much more acidic.
That is a global problem that its its hard for reef managers to really tackle. But while
that is a problem, what they can do is make sure that other factors are not a problem
to the reef. If we address a lot of those, if we improve
water quality in areas where a lot of people live, if we address some of the fishing pressure
issues, if we do coastal development in a more environmentally friendly way, I think
we could reduce those human impacts and make the reefs more likely to persist in light
of climate change. Fortunately for French Polynesia, its coral
reefs are doing fairly well compared to reefs in other parts of the world. While they have
been impacted by coral bleaching, intense storms and other natural factors, human impacts
are very low. One of the biggest challenges to marine research
is access to remote locations. Conducting research at sea is very expensive, which is
why many areas are understudied. To make the Global Reef Expedition possible,
Prince Khaled bin Sultan donated the use of one of his yachts, the 220 foot M/Y Golden
Shadow. The Golden Shadow really has an amazing suite
of capabilities. There is a large stern elevator that operates
on hydraulics and that stern elevator can lower right down in the water. And, its purpose
was to recover and launch a Cessna Caravan seaplane, and that 12-ton stern elevator can
also be used to launch some of the bigger tenders, the the dive boats that we use. The
principal dive boat is a 36 foot catamaran that we can put up to 18 scuba divers to do
our surveys on the coral reefs. The ship has a very large dive locker where
we can fill our dive tanks and in the event of decompression sickness, we have a recompression
chamber which really is useful when we are in remote locations of the world and we do
not have medical facilities readily available. Also, one of the assets of the ship is extremely
long endurance, and so we can travel about ten thousand miles with one filling of fuel,
which allows us to access remote areas of the world.
In recent years, many of the traditional funding sources for scientific research, such as large
government grants, have declined. I am seeing more and more private individuals
start to engage in things like oceanographic research. So when you see these foundations
stepping up and filling this void, it is very encouraging.
Another important aspect of the Global Reef Expedition involves the creation of large
scale maps of the sea floor. And the way we do that is we start to acquire
satellite imagery about a year before we come to the location with the ship. So that's a
very long process to acquire pictures of the earth, which are not confounded by clouds.
It is a very high resolution and new satellite, and the imagery allows us to differentiate
the character of the sea floor. So we can separate sea grass from coral from sand to
all the typical benthic habitats to you find in a coral reef environment.
The mapping project is spearheaded by Dr. Sam Purkis and his team from Nova Southeastern
Universitys Oceanographic Center in Ft. Lauderdale, Florida. Once they have all the high resolution
images of an area in hand, they begin groundtruthing on location.
We come in to the field on the ship to start to relate what the satellite is seeing from
orbit to what is really happening on the coral reef itself, on the sea floor.
We can then start to get even finer resolution differentiating between areas of coral which
are live and vibrant and healthy versus those which are in not such good shape, or perhaps
even completely dead. So we can make a snapshot, large scale, regional-scale audit of the state
of the coral reef at this point of time. One of our primary instruments is an acoustic
depth sounder. And that is this instrument here. And he is set up so that he can swing
in to the water, as I am doing now. And this instrument pings a couple times a
second, as we are moving along. And you see he is pinging quite quickly right
now. And right now it is about 14 meters deep. And here you can see the surface. It is quite
flat, so that tells us that we are over sand. Here you have the position, the latitude and
longitude of each depth sounding as it is being recorded.
So what I am getting ready to do is to drop this camera into the water, it is a high resolution
video camera with a weight on the bottom and a fin to keep it stable on 50 meters of cable.
So what we can do, is we are going to lower this into the water down to just above the
seafloor and fly it along. The camera is linked in to a very accurate GPS at the back of the
boat so we know exactly where it is, and the bearing and the speed that it is flying. And
that is the the information that we are collecting to validate what we see from the satellite.
Sam, when you're ready. All right then, neutral.
That means neutral. Here we go.
How's that Jeremy? Hold there!
Holding. We can see where we are on the satellite image
live, and we can see the video feed coming from the tethered camera on the sea floor
as well. So we know exactly what is going on.
All right, done. Coming up!
Okay, that's done. The last piece of the puzzle, is we have a
very low frequency acoustic sounder, and we use that to examine what is going on beneath
the sea floor itself. So we can see how thick a coral reef framework is. And that gives
us some idea as to whether, if we see a reef today, which is not very healthy, we can see
how well that reef has been faring over the last ten to six thousand years of growth.
And then we can see whether it is anomalous, whether the reef today is unhealthy or not,
or really is it just not a very good area for a reef to be developing.
The technique of mapping the ocean floor from satellites is routinely used but not at this
scale. Typically we look at areas of 100 square kilometers or so per year. We are now covering
25-thousand square kilometers. And so these are the largest applications of the technology
to date. And that is very exciting to be involved with.
When all of the fieldwork is done, the scientists work up their data at the universitys lab
in Ft. Lauderdale. That is a fairly lengthy process involving
computer programming and so there is a mathematical manipulation of the data set.
Using a variety of different computer programs, the experts link the depth values collected
in the field with the light values depicted in the satellite imagery to create accurate
bathymetry, or depth maps. We use the bathymetry that we gathered in
the field to train an algorithm that then says this amount of light is an estimate for
this type of depth. The groundtruthing becomes our training set,
is what we call it. So this says, we know in these areas this is what is here, this
is the water depth. And from this, now I need to extrapolate to all of these other polygons
and pixels in my area to make sure that I am um estimating things properly. Our field
efforts tend to be intense, because we need to get as much information as possible out
there, to make sure that when we come back and do the statistics and the math, we have
a strong set coming out. The team also creates habitat maps by assigning
groups of pixels in the image to different habitat classes, such as corals, or sand.
And in this program, I use the drop cam videos and some of my own knowledge to assign classes
in the image. So here I just select a bunch of sand. And
then classify it, so now it is marking it so that I know that he has been called sand.
And I do that over different depths so that we have quite a range. And here I will just
assign some reef. Using algorithms and a variety of software,
the computer can then extrapolate habitat classes for the entire image.
It uses spectral values or depth values to then group the pixels together saying this
should be a reef, this should be sand, this should be land.
What this allows us to do is to use only a few examples from the image itself to classify
the entire image. Once the process is complete, the experts
have created two kinds of maps that can be combined to make a three-dimensional map of
the seafloor. The fantastic thing about the maps is they
are digital. And they can be tendered to the public through the Internet. They can be housed
in government computer systems. Or they could be printed in to very large format posters
or or atlases. You can see there is a bathymetric map on
the left, a habitat map on the right. Here on the the water depth, the red are the shallower
areas uh with blue being moderate depths, and blue being the deepest areas that we can
see. And on the right when the habitat yellow is sand, the reds and oranges are different
coral frameworks. Green is algae or seagrass.
The data is very powerful because the maps we are producing set a baseline which can
then be revisited through time to look for regional-scale ecological change.
Another science component that will be incorporated into the mapping process is a study of the
sediments found on the sea floor. What this is able to kind of show us is a
is a spatial pattern. You can make sediment maps using the sediment
composition dataset. So we are able to map the different gradients of sand and how they
are correlated with the coral cover, algal cover and any sort of storm disturbance.
Nova Southeastern University graduate student Alexandra Dempsey collects sediment samples
on each dive. We try to sample around three to five vials
of sand. Collecting sediment on the coral reef is a
little bit like taking a blood sample for a human. With a blood sample you can tell
the condition of the body and the health and so on and so forth. A coral reef by the way
it grows and decays, it produces sediment. And by collecting that sediment we can start
to understand the history of the reef. It may seem like a rather mundane thing to sample,
but we can gather great insight about the coral reef and its history by examining it.
When we return back from the field after collecting sediment samples we go ahead and we wash them
and dry them in this lab, and we run them through this machine called the CAMSIZER.
What a CAMSIZER does is measure each individual grain to the shape of the grain, its actual
dimensions and area. And it is able to tell us what percentage
of the sample is a certain grain size. You can tell a lot by how large the grain
sizes are in a sediment sample. Where they come from, if they are from a specific type
of coral, or from an algae. Or from sponges. Alexandra can also take a closer look at sediment
samples under a microscope to better understand what may have happened in a certain area over
time. If most of the reef is dead and we really
do not have an explanation for it, we can go ahead and look into the sediment sample
and you can see what factors have contributed to the downfall of that specific site.
One of the big threats to the reefs in French Polynesia is Crown of Thorns sea stars, which
can eat large amounts of coral in a short amount of time.
If we can see crown of thorns spines we can say that's one of the factors, or the main
contributing factor to why a reef is no longer healthy.
All of the data collected on each mission is combined into a geographic information
system that is available online. And that is also handed to the country itself.
So we are trying to provide them all these geospatial tools, that they can then use to
implement conservation. The Global Reef Expedition is really only
the start of things. We are gaining great advanced knowledge of how these ecosystems
function, and how healthy they are. But people will be able to use these data, I say hundreds
of years in the future. I really hope this research that we do and
and all these resources that we are providing to the country, that they are going to be
used. That these maps can help create better management for the reefs, and that the reports
we give them helps the local stakeholders here know their reefs better, and therefore
protect them better. We have had a few success stories already,
where some of the science that we have collected, they needed the information, in order to take
some sort of conservation step. That is what is really rewarding. When I see
that we have done this work, it is good information for them. But when they take the next step,
and then do something that is really going to protect these reefs for the future.
Major funding for this program was provided by The Batchelor Foundation, encouraging people
to preserve and protect America's underwater resources. And by Divers Direct, inspiring
the pursuit of tropical adventure scuba diving.