Florida.
It s an angler s paradise.
Florida likes to think that we are the sport
fish capital of the world.
The value of recreational fisheries in Florida
overall is around $12 billion a year.
Tarpon and snook are two of the prized game
fish the sunshine state is famous for.
There s a couple of reasons that tarpon
are so enticing.
One is their massive size.
They can grow upwards to 250 pounds, almost
over seven feet long.
It s a fish that migrates great distances.
They live for a really long time.
He s big.
He jumps, it s kind of like almost the perfect
fish.
The adrenaline rush of it just really makes
it super exciting.
And a lot of fun.
The great thing about snook is that they re
ambush predators.
So no matter what you re using to fish,
you re going to see a show.
It s so much fun to catch a snook, you ll
see the bite and then they ll be airborne
just like a tarpon.
Without them Florida wouldn t be the same.
When they are young, both tarpon and snook
rely on murky mangrove-lined tidal creeks
and backcountry ponds.
I would call them essential fish habitat.
Clearly as more and more people come here
and it gets more and more developed, these
kinds of areas are going away.
Mangrove forests are inhospitable to humans,
and with nearly a thousand people moving to
Florida every day, many have given way to
coastal development.
The biggest threats to coastal fisheries are
habitat loss and degradation.
Even with snook and tarpon being mostly catch
and release, we re still seeing declines.
What that tells us is it s much more than
people fishing.
Habitat is absolutely crucial.
How do scientists study the habitat juvenile
snook and tarpon need to thrive?
And can habitat restoration help ensure the
future of the fisheries?
Major funding for this program was provided
by The Batchelor Foundation, encouraging people
to preserve and protect America s underwater
resources.
Additional funding was provided in loving
memory of David G. Parrot, by the Parrot Family
Endowment for Environmental Education
In Charlotte Harbor, on Florida s southwest
coast, tarpon is king.
Charlotte Harbor is home to Boca Grande, which
is the world-renowned tarpon capital of the
world.
We have so many fish.
In 2010, there was an economic study that
found that just locals fishing for tarpon,
so not including guides or people coming in
from other states, equated to $110 million
annually that was put right into this community.
And it s not just Boca Grande Pass that
attracts anglers to this area.
Miles of shallow mangrove creeks and flats
are a favorite with fishermen as well.
It s just a phenomenal place.
If you close your eyes for 30 seconds, you
could be completely lost if you don t know
where you re going.
And that to me is what I really love is getting
in the back country like this.
And just being in that raw Florida.
Since 1989 biologists with the Florida Fish
and Wildlife Conservation Commission, or FWC,
Charlotte Harbor Lab have tracked the abundance
of recreational sport fishes and their prey.
This Fisheries Independent Monitoring Program
consists of year-round, monthly sampling in
Charlotte Harbor.
We are a long-term monitoring program.
Our sampling protocols stay the same so that
we can track trends in populations over time.
In Charlotte Harbor every month we re pulling
roughly 120 nets.
Since 2015 the scientists are also setting
seine nets in tidal creeks that are important
nurseries for juvenile snook and tarpon.
We set the seine net in a semi-circle along
the shoreline with one person at one end,
and then the other person at the other end,
they will walk along the shore until they
meet.
And then they will pull that net in and we
will see what we ve caught.
We have snook here, this fish is probably
about a year old, we measure in standard length
which is to the end of the vertical column
right here, so this fish is 306 millimeters
standard length, fork length is 352 and the
total length is 387.
We will identify all of the sport fish and
select invertebrates.
And then we will measure most of them, and
we release them.
Our sites are randomly selected.
We re not going out to spots where fishermen
know that there s snook or that there s
no snook.
We are trying to cover the entire estuary.
And then we re stratifying by habitat type
to make sure that we re sampling in a variety
of habitats that these sport fish are using.
This includes remote mangrove-lined ponds
which are difficult to reach.
We caught 11 tarpon and 6 Mayan cyclids.
All the tarpon were all young of the year
fish.
What we do at each site is record the type
of mangrove and how inundated these mangroves
are at the time of sampling.
The juvenile fish find their way into these
backcountry waters in the summertime after
the adult tarpon spawn offshore, and the adult
snook spawn along beaches and the inlets to
the estuaries.
That s when we have our rainy season and
that s when we have our highest tides.
So, the larvae will ride those tides up the
tidal creeks, and then they will swim to the
headwaters of the tidal creeks.
And they will swim around the mangrove roots
to get into these back ponds, pretty much
as far back into the landscape as they can
go.
There s a vast mangrove forest that separates
these ponds from the creek.
So, there s just a small amount of water
that connects these coastal ponds to the tidal
creeks.
They re looking for shallow habitat with
protection from predators and an abundance
of prey fish.
They also, when they are juveniles, can tolerate
low oxygen water.
Some of these remote ponds are completely
cut off from the estuary during the dry season,
giving juvenile fish a chance to outgrow predators
that await them once access to the creek is
restored.
Another group studying tarpon and snook in
the backcountry is the Bonefish and Tarpon
Trust.
It s estimated that we ve lost about 50
percent of our mangrove habitat in Florida.
So, when you put it in terms of juvenile habitat,
you ve lost about 50 percent of your juvenile
habitat.
To the extent that overall population of tarpon
and snook is dependent on the amount of juvenile
habitat, we ll never, ever have as big a
population of those species as occurred a
hundred years ago.
We ve been spending decades managing the
fishermen and we ve been losing habitat,
and that s why fisheries are declining.
You could take every human out of here, take
every boat out of here.
If you lost the habitat.
You ve lost the fishery.
One of the things that a lot of people don t
understand about fisheries management is that
it s entirely about how many fish are harvested,
what their growth rates might be, and how
many are left in the water.
There s a real recognition of the need for
habitat management as a part of fisheries
management.
It just hasn t been implemented.
And we re at the point where if we don t
implement it, the game s over.
There are many steps that would need to be
taken to make the leap to ecosystem-based
management, and we re currently at the beginning
phases of that.
We are collecting the fish data.
We re also collecting data on the types
of habitats they are using.
We are relaying that information to the fisheries
managers.
We think that working with FWC on snook and
tarpon, because we know a lot about their
habitat use, will teach us how to do that.
So as new development happens or as different
zoning happens, it can incorporate the importance
of the fisheries.
In the meantime, the scientists are focusing
on restoring impaired habitats.
One such project focuses on an area known
as Coral Creek on the Cape Haze peninsula,
just south of the community of Rotunda.
This particular location was developed as
residential community with saltwater access,
which is why the footprint looks like a canal
system that you would see in any other coastal
community.
The development project started in the 1960s
and ran out of funding.
So the canals were left abandoned.
Currently the state of Florida owns the land
and it's managed by our Florida Department
of Environmental Protection or DEP.
The initial restoration plan was to fill in
the canals and return the topography to pine
flatwoods.
But then a group of state employees discovered
tarpon rolling in one of the abandoned canals.
Knowing this, the Southwest Florida Water
Management District, which is the agency tasked
with carrying out the restoration, encouraged
the biologists to come up with a new restoration
design that would be beneficial for the fish.
We brought the biologists together with the
engineers.
Everybody realized that this was a really
unique opportunity, we could set the different
canals into an experimental design to test
what characteristics of the habitats were
better for juvenile snook and juvenile tarpon.
Because we had six different canals to work
with we decided to go with three different
design treatments and duplicate each of those.
So two of the three designs have what we are
referring to as a sill mouth.
This means that the mouths of the canal are
built up higher than the elevation of the
rest of the canal.
So that water is only flowing through during
higher tide events or during storm surge events.
What this does is prevent larger predators
coming into these nursery habitats when the
juveniles are coming in as larvae.
We also wanted to look at depth of the water
body because snook and tarpon tend to utilize
slightly different sections of the ponds.
The tarpon tend to hang out in the deeper
holes and the snook tend to hang out more
at the edges of the marsh.
So in one of the sill mouth treatments, we
included a deep hole right after the sill
with a shallow meandering creek behind it.
Now, the reason that we have the deep hole
is because tarpon
as the water gets colder on the surface, they
can find warmer water down at the bottom of
the hole, and vice versa, as it gets hot in
the summer, they can cool off in the deep
hole.
Also there is some data that exists to show
that they can go down into that deep hole
kind of to evade the wading birds from picking
them off.
To test that deep hole theory, we created
the second treatment to have the sill mouth,
but without the deep hole.
So it's shallow throughout with the meandering
creek system on the tail end.
The third and final treatment lacks that sill
mouth.
So the water is open and flowing year round.
It also does have that deep hole again with
the meandering creek system.
To see how well the restoration is working,
the Bonefish and Tarpon Trust scientists capture
and tag tarpon and snook in all of the canals
each month.
Each snook and tarpon that we capture we scan
to see if it previously has a tag implanted.
This one doesn t so we then measure the
standard length, 251, which is to the end
of the vertebral column, we measure fork length,
this guy is 280 millimeters, since this guy
doesn t have a tag we ll go and put one
in.
First, we pull a couple of scales, make an
incision, pop the tag right into the abdominal
cavity and then we let them go.
These pit tags work just like the microchips
used in pets.
Each tag has a unique ID number which the
scientists record.
By tagging the fish over a period of two years,
the experts can determine how many tarpon
and snook are present, if they survive, and
how much they grow
So, if we recapture a fish we are able to
see how much it has grown from the time that
we tagged it to the time to recapture.
Growth is arguably one of the most important
characteristics for a juvenile fish.
As they get bigger, the more things they have
available to eat and the fewer things are
able to eat them.
Past research has shown fish grow faster when
they have access to a diverse diet.
We do lavage, or as we like to call it in
the field, puke them, pump their stomachs.
We can look at what they are eating and compare
to what s in the creeks and see if they
have a particular preference.
Because what we ve found in the past is
that altered habitats have fewer prey available
and the snook in the natural habitats are
eating twice as diverse a diet.
So right here we have a sailfin molly, but
there are also some larger scales here.
We take all this back to the lab, we can look
at the scales and figure out what type of
fish it came from and we can use that to recreate
the diet.
The scientists also use the pit tags to track
the movements of the fish.
Inside the entrance of each canal is an underwater
antenna array that can detect the implanted
pit tags and identify fish as they swim by.
Think of it as an automatic tollbooth system.
These antenna arrays, they track the fishes
movement in one canal, out the other canal.
We ll be able to see if it s more productive
for them to be secluded or if they need that
ability to swim in and out through the open
mouths of the canals.
We also have an antenna array system that
connects to the open estuary, which gives
us the final tally on emigration.
While the Bonefish and Tarpon Trust science
team is targeting juvenile snook and tarpon
in these restored canals, the F-W-C biologists
count and measure all the fish found at the
site.
We have a couple different species of mojarra,
we have some stripped mojarra, some Irish
pompano, we caught a Gulf killeyfish, sailfin
molly, gambusia holbrooki.
These are all important forage fish for juvenile
snook and tarpon.
And we also got a juvenile snook in here as
well.
He is a new recruit, young of the year juvenile
snook.
Prior to the restoration, the Bonefish and
Tarpon Trusts scientists conducted fish
sampling for 16 months at each of the canals.
That way we can compare it before and after
restoration to see which specific treatments
are more successful for nursery habitat.
While it is too soon to say if the restoration
is successful, the biologists are already
seeing encouraging signs.
From the beginning juvenile snook and tarpon
have recruited to these habitats.
And there is an incredible amount of prey
fish for them there.
We're seeing all of the same forage fish in
the restored ponds as we're seeing in the
natural habitats.
We're catching a lot more juvenile snook and
tarpon than we were before the restoration.
So that suggests that it is successful.
But it's not about the number of juvenile
tarpon and snook you see in those creeks,
it's how many survive to leave for the next
life stage.
So, if we see a lot of those fish going past
the antenna and leaving those back country
spots to join the adult population, then that's
a success and that'll take a couple of years
to figure it out.
Tarpon and snook also occur on Florida s
east coast, where the juveniles encounter
a unique set of challenges.
There s very, very little left of a natural
ecosystem in the Indian River Lagoon.
Compare this to Southwest Florida where a
lot of the habitat is still relatively natural.
The Indian River Lagoon most of its mangroves
something like 85 percent are in impoundments.
This entire area before the 1950s was known
as mosquito country.
It was unlivable for most people.
Before the impoundments were here the saltmarsh
mosquitoes made life very challenging.
They would come up in literally in the billions.
Starting in the 1950s berms were built around
the salt marshes and mangroves in this part
of the state to help control rampant mosquito
populations and make the region more habitable
for humans.
They have these circular impoundments, when
the water levels start going down they fill
them up with water.
The salt marsh mosquito needs exposed mud
to lay their eggs and to reproduce.
And by having water in these impounded areas
year-round, it essentially interrupts the
life cycle of the salt marsh mosquito.
And it did a really good job of inhibiting
mosquitos from breeding.
There are well over a hundred mosquito control
impoundments on the Indian River Lagoon.
By the 1980s several scientists and managers
realized the impoundments were nurseries for
much more than mosquitos.
They are nurseries for tarpon, for snook,
for all different kinds of fish species and
isolating all of these nurseries was not good
for the fish populations.
So they came up with a project of putting
culverts in and connecting these impoundments
back to the lagoon system.
This made it possible for fish to move back
and forth in the wintertime, when water levels
are high.
Then in the summertime, they'd close off the
gates, pump the impoundment full of water,
and now they could control mosquitoes.
And they just assumed that as long as they
had the impoundments open for much of the
year, they served a perfectly good nursery
function.
About five years ago, we decided to really
test that and see when and how do juvenile
fish leave these impoundments and go back
and join their regular population.
To do so, the scientists teamed up with the
Indian River Land Trust, which owns many of
the mangrove shorelines where mosquito impoundments
can be found.
To date the Land Trust has protected 1200
acres and 12 miles of lagoon shoreline.
Probably about seven or 800 acres is in mosquito
control impoundments.
And each impoundment is managed by the Indian
River Mosquito Control District.
They're a great partner because they understand
that science should always be looked at so
that we can try to manage these impoundments
the best way we can for the fish and wildlife
habitat.
Past research is unaltered mangrove creeks
showed that snook tended to leave their juvenile
habitat after a year.
Which is the next summer after those larvae
came into the creeks.
They didn t leave the creeks during the
winter.
So that means that the impoundments are disconnected
from the estuary when the juveniles needed
to come and go.
Knowing this, the scientists set up an experiment
at the Indian River Land Trust s Bee Gum
Point Preserve.
The basic idea was to let's catch a juvenile
fish.
Let's put little tags in them.
And let's track their movement in and out
of these impoundments.
And much to our surprise, even though we tagged
hundreds and hundreds of juvenile fish, very
few of these fish left the impoundments during
the fall, winter, early spring when the impoundments
were open, but shortly after they closed off
the impoundments pumped them full of water,
now we're getting all kinds of detections
on our antennas on the inside of the culvert
saying, Hey, I'm looking for a way out
of here and they couldn't get out.
They were stuck.
So we were perplexed at first what to do,
and we talked to mosquito control and they
agreed to open up the impoundment, open up
the gates, allow water to go flooding through
for a week.
And then they close the gates off again, pump
it full of water, and go back to controlling
mosquitoes.
And it was amazing within the first 24 hours
of opening these flood gates, we had massive
numbers of juvenile snook, juvenile tarpon,
all flooding out of the impoundment.
Once the juveniles reach out to certain size
after about a year they can no longer grow
well in this mosquito control impoundment.
So it's time to move on.
Given the success of the experiment, the research
is now being expanded to other areas.
We're repeating it in Bee Gum, we re going
to do it in two other mosquito control impoundments
here in Indian River County.
And if it's effective in all three impoundments,
now we've got something we can go to the managers
and say, Hey, look, this is really worth adding
to your management strategy playbook.
And the Mosquito Control District is willing
to work with the Land Trust, to open these
culverts periodically in the summer to allow
for the fish emigration.
The sunshine state s unique coastal ecosystems,
and the fishing opportunities they provide,
are unrivaled in the continental United States.
One of the things that brings a huge number
of people to Florida is a quality of life.
Certainly, you come to Florida for the weather
and for the water.
But as more and more people head south to
experience the Florida lifestyle, many of
the natural qualities that attracted them
in the first place are in decline.
That lifestyle is entirely dependent on a
functioning ecosystem.
So, as those habitats are degraded our quality
of life declines as well.
We want to be able to protect it and keep
it going for generations.
Major funding for this program was provided
by The Batchelor Foundation, encouraging people
to preserve and protect America s underwater
resources.
Additional funding was provided in loving
memory of David G. Parrot, by the Parrot Family
Endowment for Environmental Education.