>>NARRATOR: They are an ancient
species of flowering plants

that grow submerged
in all of the world's oceans

from the latitudes
of northern Alaska to the tip

of South America.

Sea grasses evolved during
the age of the dinosaurs

nearly 100 million years ago
and are found toda

in bays and estuaries
around the globe.

In shallow tropical
and subtropical waters,

these "prairies of the sea"
link the offshore coral reefs

with coastal mangrove forests.

They provide food and shelter
for many marine species

that will one day inhabit
the reefs.

Sea grasses and mangroves
stabilize coastal sediments

and create buffers against
storm surge and flooding.

They remove carbon dioxide
from the atmosphere,

filter contaminants
from coastal waters,

and add value
to local economies.

But sea grasses are in decline
globall

and mangroves are being lost
to coastal development.

>>These areas are degrading
right now.

It's not 50 years from now
or 100 years from now,

but it's occurring right now.

>>The rate at which
we're losing sea grass habitat

globally could result
in an ecosystem collapse

from the bottom of the
food chain all the way up.

>>NARRATOR:
Will restoring sea grass

and mangrove communities
help sustain the ecological

and economic values of the
ocean's bays and estuaries?

And how will rising sea levels
impact their survival

in the future?

>>Major funding for this
program was provided

by the Batchelor Foundation.

Encouraging people
to preserve and protect

America's underwater resources.

>>NARRATOR:
Over the last few decades,

worldwide human populations
have increased dramaticall

along coastlines.

At the same time, sea grasses
have declined at a rate

of nearly 7% per year--
a rate higher than the loss

of coral reefs
or tropical rain forests.

Storm water runoff from coastal
communities and human activities

along the shoreline contribute
to the decline.

Boat groundings and anchor
damage add to the problem.

Unlike the more recognizable
icons of the seas,

the value of sea grasses
and mangroves

can be easily overlooked.

>>If you just casually read
newspapers in places

that science stories
are published,

you often read about
tropical forests,

you often read about
coral reefs,

and occasionally you'll even
read about mangroves,

but you almost never read about
sea grasses.

Sea grasses are the
Rodney Dangerfield

of coastal marine ecosystems.

They really get no respect.

>>NARRATOR: But researchers
have discovered that sea grasses

and mangroves deserve
a great deal of respect

for their many values
in the ocean.

>>Sea grasses keep erosion
down, they lock sediments

into the bottom, and they
actually remove sediments

from the water column.

When that happens, it maintains
a clear water column

so a lot of light
reaches the bottom.

If sea grasses were to
disappear, then all of a sudden

they are no longer holding
these sediments in place.

Sediments get up in the water
and the water

becomes very, very turbid.

>>That's really important
when you're thinking about areas

that are heavily populated,
where folks like to recreate

where sediments
can be stirred up.

They kind of root them down
and keep them stable.

And they provide some hurricane
protection,

much like mangroves do
on a global scale.

You've got sea grasses
and mangroves

that break wave action
when storms come,

and that also provide
nature's way of stabilizing

the shoreline.

>>We live in an area
of the world where we get

these catastrophic storm events,
hurricanes and tropical storms

and, where they hit the coast
they can definitely create

erosion problems.

And what we find is that areas
that are protected or buffered

by mangrove forested wetlands
tend to do much better.

And then we lose a lot
of coastline in areas

where we removed mangroves
and replaced them

with things like seawalls.

>>NARRATOR: Still, some
of the most important values

of these resources
are less obvious.

>>It's been shown that about
a hectare of sea grass,

which is equivalent
to a soccer field,

can use the same amount
of nitrogen that would come

from treated sewage
from 800 people in one year.

And then, if you're looking
at the carbon numbers,

sea grass can fix the same
amount of carbon

per meter squared in a year
that you would produce

by driving your car 7,500 miles.

Just the amount of nitrogen
they pick up is worth

$19,000 a year for that
one little spot of sea grass.

And you start to look
at everything else

that is associated with them.

You're not talking a monetary
amount for fisheries

because you've got the shrimp
industry down here

in South Florida, you've got all
of the sports fishing,

as well as most of the fish
from either the mangroves

or the coral reefs having
some sort of connection

with sea grass.

>>Sea grasses and mangroves
provide the nursery habitat,

the foundation
of our ecosystem,

and without having
a healthy nursery habitat

where fishery industries
can survive

and our tourism industry thrives

because we've got this industry
that depends on having

nice clear water and habitat
where fish can grow

both for sustainability
and sustenance for people to eat

and also for our tourism
industry where people

like to recreate.

From the basic part of that
food chain up through

human consumption you'd have,
really, an ecosystem collapse.

>>It certainly is a crisis.

Sea grasses are very valuable
for the ecosystem services

they provide, besides being just
hotspots of biodiversit

and beautiful places to visit.

>>I'm fascinated by sea grass
habitats.

On the surface you look
at a sea grass habitat

and you see a bunch
of green grass,

essentially, that doesn't look
too different from your lawn,

for example.

But sea grasses,
or the habitats,

are incredibly complex.

There are so many different
organisms that live there,

there are so many different
bio-geochemical cycles

and processes that are going on
in there.

If you put your face up close
to a sea grass habitat,

you'll be amazed at the number
of different things

that you'll see
on the small scale.

>>NARRATOR: In the sub-tropical
waters of southeast Florida,

neighboring metropolitan Miami,
Biscayne Bay Aquatic Preserve

manages nearly 70,000 acres
of submerged land.

Nearly three-quarters of that
is covered by sea grass.

Mangrove forested islands
and shorelines grow adjacent

to these sea grass communities.

The most common variety,
red mangroves,

are found growing
at the water's edge.

Behind them, black mangroves,
and farther upland,

white mangroves.

Historically, Biscayne Bay
received freshwater

from the Everglades,
but in modern times

the hydrology has been altered
by drainage canals,

channelized rivers,
and changes in the flow

of ground water into the bay.

The diversity of species
has also changed,

but it still remains an estuar

where freshwater
and saltwater meet.

>>One of the things we do
is form partnerships

with local resource agencies,
universities,

researchers who are looking
at what the resources are

in Biscayne Bay so that we can
get a better understanding

of what's there now, but also,

how have things changed
and how are they changing?

>>NARRATOR: Marine biologists
are monitoring

salinity, sediments and
organisms that live on

sea grasses found in Biscayne
Bay with a long term goal

of determining what effect
a new freshwater canal

flowing into the bay will have
on the ecosystem.

>>This project
is directly related

to the Everglades
Restoration Project,

and what's going to be
happening is,

the freshwater regime of south
Florida is going to be changing.

And everybody that's involved
wants to try to get an idea

of what and how these changes
are going to be affecting

what's already here.

Overall, if you have
salinities changing

on a much larger scale,
then you start getting into

chemistry a lot more:
how warmer waters are going

to be acidifying with
higher levels of CO2.

That's going to be affecting
how the sediments actually work

or don't work.

It starts to get pretty ugly
pretty quick.

We don't know exactly
what's going to happen.

>>NARRATOR: Photo archival data
of the sea grass beds

is recorded with a
specially designed boat

and shallow water positioning
system known as SWAPS.

>>We've got a glass bottom boat
so that you can see the stuff

that's out there.

We've got a digital camera
attached to the glass bottom.

We can move that around
as we need to.

That runs directly through
a computer,

goes straight to a hard drive.

We've got GPS, so it codes every
photo with exactly where it is.

Even if we're doing a straight
line or just trying to sit

in one spot, each one of these
is tagged so precisel

that we can follow it around,
because sea grass doesn't grow

all the time as just
one big meadow like your yard.

There's going to be
little patches of it.

This gives us a nice snapshot
of the community as it is

right up against the mangroves,
and how that changes as it moves

into a little bit deeper water.

We're going out,
and year after year,

taking photo quadrants,
basically, and so that wa

in the future we can always
come back if we need to check

for any specific organisms
or any specific changes

that we may have missed
on our preliminary analysis.

>>NARRATOR: Sea grass
and mangrove communities

in Biscayne Bay nurture
juvenile fish

and marine creatures that feed
and find shelter here.

Some will make their way
offshore to the coral reefs.

Others will live out their
entire life cycles in the bay.

More than a hundred bottlenose
dolphins reside in the bay,

stalking fish around
the sea grass beds.

Sea grasses are a primary
food source for manatees,

but as opportunistic feeders,
they will consume

low hanging mangrove leaves.

Sea grasses in tropical and
subtropical bays and estuaries

around the world have
a relationship with mangroves,

like prairies do to forests
on land.

>>A good example of this
is along the mangrove fringe

down in the southern part
of the aquatic preserve

near Chicken Key
and the Deering Estate.

You've got an expansive
mangrove forest right adjacent

to the shoreline and then out
from that for a few miles

you've got dense sea grass beds.

>>NARRATOR: The prop roots
of mangrove trees suppl

food and shelter to some
of the same marine organisms

and fish that are found
in sea grass beds.

Because many near-shore
and offshore species rel

on mangroves as a nursery,
when mangrove habitat is lost,

fisheries soon decline.

Human impacts on these
ecosystems are a clear challenge

for resource managers.

In the 1960s, developers
acquired a section of shoreline

in the northern tributary
of the ba

and cleared the mangrove forest
to dredge and build a marina.

Years later, the site
was acquired to form a part

of the Oleta River State Park.

Today, it's being restored
to its natural condition

as a mangrove wetland.

>>This is a red mangrove
propagule that has just started

to put out some roots
and some leaves.

As you can see, they are about
six to sometimes nine inches

in length and they come off the
tree as a very cigar shaped--

some people say
it's pencil shaped--

very long sort of
propagule seed,

and they float in the system
until they find

some substrate, and the one end
is a little bit heavier

than the other end
and it tends to take root

and get in an upright position.

And again, you have to remember,
the water is going up and down

as this is all happening.

Then once it starts to establish
some root into the substrate,

it will start to grow
and the mangroves grow

about two feet a year.

They differ from one location
to another,

but that's a pretty good
average.

The red mangroves
will grow up to 150 feet

if they didn't have impacts
as far as storm impacts.

And in this area we see them
from 80 to 100 feet tall.

Unfortunately, we have
our frequency of hurricanes here

is great and as a result
our mangroves are not as tall

as some of the ones
in southeast Asia,

where they have a lower
frequency of storm events.

These channel ways feeding into
the site were designed

minus three feet.

It's really been exciting
in our restoration plans.

We not only just have
a plain of mangroves,

but we also have these
tidal creeks and channels

and tidal pools.

It's amazing to see the life,
the abundance of life

that comes in and succeeds
through time.

We've seen fisheries that have
come into areas,

and just the species' richness,
or the number of different types

of fish or crabs or shrimp,
have just gone right off

the graph as far as
the number of individuals

and the diversity--
the different types that come

into an area once it gets
established.

My biggest thrill about
all of this is pretty much

at a stage that we're at now
with this project here,

where we're pretty much
concluding the construction,

we're starting to plant the site
with volunteers,

and that's another big part
of this effort,

is to get the community in
to obtain a sense of ownership,

stewardship with the project.

And families come out
and can plant these mangroves,

and come back and see
the abundance of life

and what they've done,

and feel a part of the overall
restoration.

>>NARRATOR: But balancing
resource management

and restoration with
recreational use

is a steady challenge,
particularly for specialists

in Biscayne National Park,
located at the southern end

of the bay.

It's a shallow water environment
with submerged resources

like sea grasses
and coral reefs--

a popular recreational area, but
one that's frequently impacted

by boat groundings
and propeller scarring.

>>We're trying to put
the sediment back in the holes,

or the scars themselves.

Sea grasses cannot grow well
in the water column itself,

they need sediment to grow in,
so until we replace that,

those injuries take years
and years and years to recover,

if at all.

We're putting in sediment
that's very fine

and it can cause a very large
turbidity bloom in the water,

which is not a good thing.

We're actually required through
state water quality standards

to control that turbidity
very carefully.

So we will put up
the yellow construction boom

around the site
that we're going

to be working at and make sure

that there is really very little
option for leaking.

Then we'll bring the sediment
in on barges.

Sometimes we use
containerized sediment,

for example, in a burlap bag.

Sometimes we put the sediment
that's loose.

We use a crane--
some kind of crane--

to actually put it in the hole.

We have divers in the water
feeling out the surface

with their feet to figure out
where we need to put more,

you know, so we can
kind of place the sediment

exactly where it needs to be.

And the other thing
the divers are doing is

collecting water samples
for turbidity water monitoring.

>>NARRATOR: In the final phase
of this restoration,

healthy sea grasses will be
transplanted to the site,

a method having great success

in the Channel Islands
National Park

off the coast
of southern California.

>>All right, I'm in.

>>NARRATOR: The rich sea grass
habitats of the Channel Islands

sustain an abundance
of marine life,

offering food for some
and shelter for others.

Some of its species are found
nowhere else in the world.

Here, resource managers are
harvesting healthy sea grasses

to transplant in damaged areas.

This five-year old restoration
project has expanded

the sea grass beds
up to a mile away,

adding new habitat
for a diversity of species.

But, it takes an informed public
to share the responsibilit

for sustaining these ecosystems,
and resource managers

want to engage people as well
as local governments

in promoting the best ways
to enjoy the bays

and estuaries while protecting
the resources.

>>On behalf of Miami-Dade
county and this community,

do hereby proclaim March 2010
as Sea Grass Awareness Month.

>>Very good.

(applause)

>>NARRATOR: But will human
intervention be enough?

And in time to make
a difference?

>>One of the things
that is at the forefront

of everyone's mind is,
we're managing these areas,

but what does that mean
in 25 years, or 50,

or 100 years?

We'll be...
this will be underwater,

this island that we're sitting
on right now.

So it's a quandary.

>>NARRATOR: In southwest
Florida's Ten Thousand Islands,

bottlenose dolphins
corral their pre

in one of the most productive
mangrove estuaries in the world.

From the air, the islands look
much the same as they have

for thousands of years,
but today they are ground zero

for researchers trying to solve

one of the great scientific
problems of the future:

predicting sea level rise.

At Rookery Bay National
Estuarine Research Reserve,

scientists are trying
to determine how changing seas

will affect the Ten Thousand
Islands' mangrove forests

and low lying coastline.

>>We know without a doubt that
sea level rise is increasing

and it's actually an accelerated
increase.

That puts communities
in southwest Florida at risk,

not just here
in southwest Florida,

but I would say particularly so
here because people live

on Marco Island and Naples
and the surrounding areas

are living in communities
in these built landscapes

in a very low lying elevation.

>>A lot of the mangroves
we have around Rookery Ba

are actually growing
on living oyster reef,

and if the water quality
conditions are good,

and in most cases in Rookery Bay
that is the case,

as the reef slowly expands,
then we can also see

an expansion of mangroves
that occurs at the same time.

Oysters have a tendency
to grow up at a certain rate

off of the sea floor,
and if those oyster reefs

are growing faster
than sea level is going up,

the oyster reefs become
emergent.

They come out of the water
and then they become areas

for recruitment for mangroves.

So what was an oyster reef

becomes a mangrove-forested
island,

and those mangrove-forested
islands

have snaking-like shapes,

dendritic kinds of patterns,
and it's those islands

that give the Ten Thousand
Islands their name.

Now that sea level rise
has accelerated,

that rate of sea level rise
is faster than oysters can grow,

so that balance will shift
and has already shifted

and it's quite possible,
I would venture to say likely,

that the Ten Thousand Islands
will disappear given

the current rate
of sea level rise,

which will completely change
the configuration of the coast

and completely change the
estuarine ecology of the coast,

because those Ten Thousand
Islands also serve

as entrapments
for fresh water that create

the brackish water
that serves as the nurseries,

serves as the place
for sea grass development,

serves as a place for other
oyster reef development.

That's all likely to change.

>>NARRATOR: Researchers
are studying sediment samples

from the Ten Thousand Islands
to determine changes over time

in the mangrove communities as
a consequence of sea level rise.

These sediments indicate
a shoreward retreat

of southwest Florida's
mangrove coastline.

They're also finding evidence
of saltwater intrusion

in the freshwater marshes
of the Ten Thousand Islands

National Wildlife Refuge.

Arrays of circular sub-tidal
ponds have been photographed

from the air.

Patches of mangroves
are taking root

where only freshwater plants
once grew,

another sign of sea level rise.

>>Since humans have become
industrialized,

since humans have been recording
history in history books,

we've been around during times
of modest sea level rise rates.

And we have barrier islands and
bays, and Ten Thousand Islands,

and Biscayne Bays
and Florida Bays.

Those are all there because
a modest rate of sea level rise

has allowed those features
to develop.

Now, again we see
that in the sediments

over the last 5,000 years.

Now flash forward
to industrialized world

and climate change
and enrichment of CO2

in the atmosphere,
there's clearly a record

in those sediments that
sea level is accelerating.

>>NARRATOR:
Scientists project the retreat

of southwest Florida's coastline
if sea level should rise

from its current level
one meter at a time

up to an additional nine meters.

>>Projections for much faster
rises in sea level

over the next 100 or 200 years
would suggest to us

that the area we're standing in
now will soon be under water.

So one may ask the question,
why bother protecting

the sea grasses here
if the coast is going

to migrate away from here?

One reason is because there will
always be a coast

and sea grasses will continue
to respond and move shoreward

as sea level goes up, as long as
humans don't armor the coast

to such a point that a wall
is built around human cities

and they continue to go up
as sea level comes up.

>>NARRATOR: But how fast
will these changes occur?

And will sea grasses
and mangroves continue to yield

their many ecological
and economic values

with the changing seas?

For today's researchers,
these questions are part

of an experiment in progress,

with the answers waiting
somewhere in the future.

>>Major funding for this
program was provided

by the Batchelor Foundation.

Encouraging people
to preserve and protect

America's underwater resources.