- This video was supposed to be
about the role of sulfur in reef tanks.
Sulfur can be used to reduce the nitrate
in our tank's water
by converting it to nitrogen gas
and you do that using a sulfur reactor.
The end.
Hope you enjoyed the video,
don't forget to subscribe.
What I actually discovered though,
is way more interesting.
Sulfur compounds released by coral
can actually change the weather.
Hi guys and girls, I'm ReefMan,
and this is all about the sulfur cycle in reefs
and its influence on the climate.
Coral reefs are just of the coast
of more than 100 different countries
and they contribute
over $375 billion every year to those economies.
Reef systems like the Great Barrier Reef
are so big that they can be seen from space by astronauts.
The Great Barrier Reef in particular
is made up of thousands of individual reefs
and as a whole, it's home to about two thirds
of the world's coral species.
The Great Barrier Reef
contributes over $5.8 billion annually
to the Australian economy,
and most of that's from ecotourism,
diving, that kind of stuff.
Now we usually think of changes in climate
as being driven by major events,
things like volcanoes,
human activity, that sort of stuff.
But it's much more complicated than that,
and anyone who says that there is just one thing
that impacts our weather is really just being dishonest.
Everything works together in the overall climate system,
and it turns out,
coral reefs can play a big role
through their production of a chemical
called dimethyl sulfide or DMS.
Dimethyl sulfide is produced by the breakdown of chemicals
which are in turn produced by both plankton
and also the dinoflagellates that live inside coral.
From the water, DMS escapes into the air via waves
and bubbles and things like that
and you can actually smell it.
You know that smell that Acropora has
when you have it out of the water?
Or the smell that you have at the beach?
That is actually largely DMS.
It's got a very distinctive smell to it
and we can detect it at very low concentrations.
So how does DMS change the weather?
Well, as it's brought into the atmosphere,
and creates a fine aerosol
which combines with water vapor and it produces clouds.
You've probably heard of cloud seeding before
just spraying fine aerosols into clouds
to provide a nucleus for rain drops to form around.
Well the same thing happens here,
only it's just all natural.
As DMS rises into the atmosphere low clouds are formed
the kind that you often think of
when you imagine a tropical island.
With enough time and the right conditions,
they'll even produce rain.
And indeed, some of the rainiest parts of Australia
are in locations where wind blows onto land
after nearly the entire distance
of the Great Barrier Reef has been crossed.
And these locations measure their yearly rainfall in meters.
As clouds are formed more and more light
is reflected back away from the water's surface.
This leads to a small
but measurable impact on sea surface temperature.
As coral reefs produce DMS,
clouds form, they limit the impact of the sun
on the surface of the water,
and that, in turn reduces the temperature.
Acropora produces more DMS than nearly any other coral
and you can verify this
by smelling your own coral.
What one smell more like the sea?
It's gonna be your Acropora.
It's actually the dinoflagellates inside the coral
that produce the compounds that lead to DMS,
but we can think of it as just the coral itself
since the overall reef
almost all of those dinoflagellates live in
or around coral tissue.
It's also released in coral mucus, films,
things like that, that are carried away
by the ocean current.
Coral expels about half a percent of their dinoflagellates
every day just as a normal function of its life.
Over an entire reef
this ends up being a huge amount of DMS
that is liberated every day.
Birds use DMS and its characteristic scent
to locate feeding grounds,
and it's even thought that the earliest people
living in the Pacific
might have been able to use that telltale scent
which can carry for miles and miles on the wind
to navigate between coral reef-fringed islands.
So, as coral grows and releases DMS
it sort of regulates sea surface temperature
by increasing the cloud cover.
That's pretty cool.
There is a limit to this though
when the temperature of the water
goes over about 30 degrees celsius
Acropora starts using DMS as an antioxidant
rather than releasing it.
This means that as ocean water temperature increases
for whatever reason
this coral-cloud temperature regulation cycle
will shut down,
leading to more sun because of less clouds
and higher sea surface temperature,
which cause less and less DMS to be released.
You can see how this might turn
into a self reinforcing cycle,
and how that might be bad news for reefs
that are temperature sensitive..
I thought this was really cool.
Who would have guessed that coral reefs
are able to change the weather?
I had certainly never heard of this.
I started just looking for information
and studies about Sulfur in reefs
so that I can give you guys
an interesting video all about sulfur
but I came across this incredible system
where coral reefs produce these chemicals
which produce clouds and rain.
The world is just such an incredible place,
I thought this was way more interesting than,
you know, sulfur reduces nitrate, yay.
I hope you found this as interesting as I did.
Thanks for watching, have a fantastic day,
stay safe, stay healthy.
And I will see you next time, bye.