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This week on Waterways.
The effects of the 2010 Cold Front;
and Tamiami Trail Reconstruction.
January 11th, 2010; water temperatures in Florida Bay
register 41 degrees Fahrenheit; the coastal mangrove
zone of Florida Bay shows temperature readings as low as
34 degrees Fahrenheit; the result: millions of fish dead.
This is the largest fish kill resulting from cold weather to
hit south Florida in more than 30 years.
The bay side shore lines of the Upper Keys
here were just filled, covered with dead fish.
Within Everglades National Park, some of the shallow basins,
North of Flamingo, where a lot fo the fish were seen,
The boat basin at Flamingo; I estimated a little under five
thousand snook and tarpon alone in the boat basin at Flamingo.
In one back-country lake alone where I did a detailed count,
this is just north of Flamingo, I counted through estimating in
groups of ten, thirty-nine thousand, eight hundred combined
snook and juvenile tarpon dead.But widespread death did
not stop with fish.We observed approximately 140 dead
crocodiles, really large animals, some of which were 6 to
10 feet long that had been around for a while and they
succumbed to the cold.
This is another species that recently had been considered a
conservation success story.
They had been reclassified from endangered to threatened; a
great success in the endangered and threatened species world in
regard to management.What killed these animals was extreme
cold temperatures not normally seen in south Florida winters.
But south Florida and the Florida Keys have had these cold
temperatures in previous years without the massive loss of
life.
So what was so unique about this cold snap?
The durationnot only was it extremely cold, it also lasted
many, many days.And we do see cold related fish kills every
couple of years.
But this was a much more significant event than what
we've seen in the past thirty.
This seemed to be maybe a thirty or a forty year event.
The last time we saw an event like this was 1977 was fairly
similar to what we saw in 2010, just based upon the amount of
dead fish that were observed.To document what was
happening, resource managers and environmental scientists sprung
into action.So we got up in helicopters and did aerial
surveys of most of the marine and estuarine areas in the park
to try to better describe the extent and magnitude of the fish
kill and the impacts on other wildlife.Throughout the next
few days and weeks, the dead were counted and data were
analyzed.
Pete Frezza documented 54 different species of marine fish
that died.Now a fish like a snook and a bonefish and a
tarpon, they begin to start losing their life functions at
around fifty, fifty-two degrees.
And we had that water temperature for four or five
days in a row and when I was out there trying to document this
event that second week of January and what you would see
was the snook, they lose their equilibrium first, they can't
stay upright.
So they start going upside down.
That's the first signs of what you see with a fish in trouble
is them starting to lose equilibrium and turning
upside down.
So I saw that for a couple of days, about two days with the
snook and the juvenile tarpon before they actually died.
Fish kills and dead manatees are hard to miss.
Wind and currents tend to push floating dead fish and other
animals towards the shoreline where they are readily observed.
However, what about those species whose impacts weren't as
obvious because they took place below the surface and further
from shore?Corals really like to live in tropical water, in
tropical weather; where water temperatures, they thrive in
water temperatures that don't really get below in the 70s is
about the coldest they like and into the upper 80s for the warm
side of things.
The water temperatures we actually saw, readings that went
down to as low as 48 degrees on parts of the reef.
And this is very important because the corals that live
here don't do well once the water temperature gets below
about 52, 54 degrees.
And what happens when they get exposed to real cold water is
they die off.By mid-January there were many reports of coral
bleaching, a stress response in corals normally seen in the
warmest months of the year when temperatures increase; however,
corals also become stressed when temperatures dip below the
corals preferred temperature threshold.
Science divers from 13 different agencies responded to these
reports in a two-week monitoring effort lead by The Nature
Conservancy.
During that timeframe, divers conducted 80 surveys all the way
from Key West through Florida Keys National Marine sanctuary
and north through the reefs of Palm Beach County.
How were they able to get these surveys done so quickly?
Turns out that rapid response teams were already in place
through the Nature Conservancy's Florida Reef Resilience Program
that has been conducting late summer reef monitoring along the
Florida Reef Tract annually since 2005.
Divers discovered that many of the corals weren't just
bleached, but dead from the acute stress of rapid
temperature declines.When a coral first dies off that tissue
is gone but that coral structure is really there and you can see
all the details within the coral skeleton.
Over time, over a period of about three months, that erodes
and you can no longer see that detail within the structure of
the skeleton.
And that's how we can determine if it recently died or if it
died in a longer timeframe.What Byrne and the
multi-agency monitoring team discovered was that coral deaths
from the cold snap were not uniformly distributed across the
entire reef tract.
Some colonies fared better than others, and it depended on their
location.
The shallow waters of Biscayne Bay and Florida Bay, as well as
the nearshore patch reefs, showed the greatest coral
losses, at times greater than 10 percent.
Coral loss had everything to do with proximity to cold water
pulses.
In certain locations near channels, corals within 300 feet
of each other experienced 10-to-15-degree
temperature differences.
On a positive note, the reefs found in deeper waters and those
off-shore were spared thanks to the warmer water influence of
the Florida Current.And we also had the Gulf Stream in
pretty close and that was actually over the fore-reef
which is the main barrier reef system that is real popular with
diving and all the tourists go out to.
That area was buffeted by the Gulf Stream and never got the
cold water effect in it.
So we didn't see any effects on those sites out there.
But the inshore areas, the reef areas that are real close to the
islands and those mid-channel reef areas is where the cold
water came out.Until 2010, a widespread cold-water coral
die-off hadn't occurred in Florida since the late 1970s.
And never before has a cold-water event been as well
researched and documented, thanks to the existing
monitoring infrastructure of the Florida Reef Resilience Program.
This rare cold-water data allows researchers to learn more about
coral responses to cold stress, and provide resource managers in
south Florida with information to better understand and protect
these critical habitats.So in terms of managment after an
event like this, you know of course we can't control the
temperature but we certainly can do things to protect the
resources out here after we have an event like this.
And the state, the Florida Fish and Wildlife Conservation
Commission did a great job of protecting the snook; you know
they did a detailed survey of the loss of snook based on
estimates from surveys and realized, hey the numbers show
what the people were seeing.
The snook really took a big hit.Snook probably took one of
the hardest hits from the cold event we had in January 2010 of
all the species in the park.
They're a fairly tropical species and we had really
widespread mortality as a result of the cold.
Resource managers at Everglades National Park
have been meticulously collecting data from fish
surveys for years.
By interviewing anglers coming in from a day of fishing, they
determine the catch per unit effort.
Which means: how hard and how long are anglers attempts to
catch a specific species.So after collecting all the
information that indicated that the productivity of the fishery
dropped dramatically relative to the prior twenty years, we
worked very closely with the Florida Fish and Wildlife
Conservation Commission.
They are the state agency that regulates fisheries here in the
state and after working with them, sharing data with them,
they made a recommendation to the commissioners in the state
to keep snook harvests closed for an additional year.South
Florida, the Everglades and the Florida Keys provide habitat to
a unique mix of tropical and temperate fish species.
Snook, bonefish and tarpon like warmer, tropical waters; while
species such as redfish, spotted sea trout and black drum, like
cooler, temperate waters.Now if you were a snook fisherman or
a bone fisherman you would have thought this was a terrible
event.
And that's completely understandable.
However, if you were into red fishing this is a fantastic
event.
Because something very interesting, what we're seeing
out here in terms of the fishing in Florida Bay is we've seen an
incredible increase in the numbers of redfish in Florida
Bay, particularly juvenile redfish.
There's just a mass of these small redfish came in, and don't
know if it was lack of predation or lack of competition from
tropical fish species, but the redfish population here in the
southern Everglades has done fantastic after this cold
event.The red fishing has been off-the-charts.
People have been catching red fish like they've never caught
before in the last 20 years.
And we're so happy to see a silver lining as a part of the
result of the cold impact.Another group of fish
that benefited from the cold snap of 2010: native fresh water
and salt water prey-fish.
Monitoring indicates there was a noticeable increase in the small
native prey-fish populations that form an important link in
the food chain for birds and other fish.
These native prey-fish have been suffering from the infiltration
of non-native fish that have overtaken their habitats.We
have about sixteen species of non-native fish that live in
Everglades National Park and throughout the Everglades.
And those fish species are typically very tropical.
They come from South America, Southeast Asia and they don't
tolerate cold temperatures well.Unlike many native fish,
non-native tropical prey-based fish, like the Jewel cichlid,
can't survive cold weather.
This was good news for south Florida's native species.This
event really turned out to benefit these native fishes
because, really for two reasons; first of all, there was a
release of competition with these cichlids that had become
really over-run in the southern part of the Everglades and
secondly it was a lack of predation.The January 2010
cold snap highlighted another issue that, thankfully, is being
addressed: the need for long-term monitoring.
Pete and his team at Audubon's Tavernier Science Center were
able to accurately measure the effects on fish communities
because of their vast database going back 30 years.Just a
thirty year data-set that we have here at Audubon, you can
clearly see that the deviation or variance in temperature over
the course of a year is increasing.
So the cold is getting colder and the warms are getting
warmer.
It's absolutely true.And what we know from working with some
of the best scientists that are studying climate change and sea
level rise in Florida is that we may actually be expecting more
extreme temperatures, not only on the warm end but also on the
cold end.
And if that's the case, there's some possibility that what we
experienced in January 2010 was related to climate change
although we really can't be sure.
What we can be sure of is that scientists are telling us to
expect more extreme temperature swings both on the cold end and
on the warm end.Like hurricanes and wildfires, the
extreme cold experienced in January 2010 was a natural
event.
The south Florida and Florida Keys' ecosystems have evolved to
tolerate conditions such as thesefor short periods of time.
But, if these recent weather events can be attributed to
climate change and begin to occur more frequently, what
then?
Will plants and animals be able to adapt to these rapidly
changing conditions?Climates change; they're cyclic
throughout the time of the earth.
We've had lots of different times where the climate has
changed.
What makes this time frame different than those is the time
that it's taking.
Normally climates change on a geological time scale where
we're talking hundreds, thousands of years, for the time
to change, and the systems and the animals have time to adapt
to that; enable to still thrive and move to a different area
where they can survive and live really well.
But what we're seeing is those climates are now changing on a
much more rapid pace where the animals and the ecological
systems don't have time to adapt to that.Just as a person's
compromised immune system impairs their ability to fight
even a small illness, so too is a stressed ecosystem less able
to bounce back when faced with additional threats.
Our environment's resilience and adaptability to natural
stressors can be enhanced through the reductions of
human-caused stressors.
Such is the role of resource managers at the Environmental
Protection Agency, Florida Fish and Wildlife Conservation
Commission, Florida Keys National Marine Sanctuary, and
National Park Service.
Through projects and regulations that address human-caused
threats such as pollution, marine debris, vessel
groundings, and poaching resource managers work toward
building an environment better equipped to respond to climatic
changes and natural stressors.
An environment that will continue to support the economy
and quality of life in south Florida for ours and
future generations.
There are no other Everglades in the world.
They are, they have always been, one of the unique regions of the
earth, remote, never wholly known.
The miracle of the light pours over the green and brown expanse
of saw grass and of water, shining and slow-moving below,
the grass and water that is the meaning and the central fact of
the Everglades of Florida.
It is a river of grass.
There's a road in south Florida that connects Miami to Tampa.
Nearly one hundred miles of this roadbetween Miami and
Naples materials excavated during the
construction of the canal that runs adjacent to the roadway.
Completed in 1928, the Tamiami Trail effectively shut off the
natural flow of water into Everglades National Park.
At 2,400 square miles, Everglades National Park is one
of the nation's largest national parks.
However, the entire Everglades ecosystem was historically FOUR
TIMES this size and was covered by a slow-moving sheet of water
flowing from Lake Okeechobee to Florida Bay
Stoneman Douglas referred to as the "River of Grass."
In 1900, people weren't flocking to south Florida; in fact, it
was still fairly remote with a population of only 50,000.
The thousands and then millions more that did come over the
ensuing decades demanded protection from devastating
floods that accompanied the all-too-common tropical storms
and hurricanes.
At the same time, they also needed reliable access to fresh
water during the droughts of the winter dry season.
To do this, the historic Everglades was divided into a
series of impoundments to conserve and store water during
the dry season, as well as provide flood protection to
south Florida's growing population centers.
While these modifications greatly altered the natural
hydrologic conditions within the wetlands, they also affected
Everglades ecology.Used to be a really broad, over-land sheet
flow regime that extended all the way from Lake Okeechobee
down all the way to the terminus of Florida and Florida Bay.
It was an uninterrupted sheet flow regime.When the Tamiami
Trail was built, it essentially created a dam right across the
middle of the Everglades ecosystem.
While this hurt the Everglades, it was the building of over
1,400 miles of canals and levees that really damaged the natural
ecosystem.
The engineering that moves water and prevents floods now diverts
about 1.7 billion gallons of fresh water to the coast each
day.
This water no longer flows in a slow-moving sheet across the
south Florida ecosystem to Florida Bay; and evidence points
to the absence of sheet flow as one reason for the disruption of
plant and animal communities in the Everglades;loss of wading
birds; and fewer fish and pink shrimp in Florida Bay, the
Florida Keys and the Dry Tortugas.
Management of the water within the Everglades to meets human
needs wreaked havoc on the ecosystem.
And, while it caused some areas to be too dry, it caused other
areas to be too wet!In some of the areas that were not dried
out, we essentially had too much water; and this in fact
contributed to problems that we started noticing back in the
1960s as well as we started seeing a higher increase in
alligator nest flooding occurring and the populations
size of alligators plummeted.
We also have really good records now on some of the endangered
species such as the Cape Sable seaside sparrow that had been
dramatically affected by too little water in some areas of
the Everglades and too much water in other portions of the
Everglades.Many species suffered from the change.
The natural rhythm of wet and dry cycles that Everglades'
plants and animals evolved in over thousands of years
had suddenly changed.
Scientific data collected over many years were proving to
officials tasked with preserving the natural ecosystem that the
Everglades was in trouble.
In fact, the park was first listed as a World Heritage Site
in Danger in 1993 in part because of a marked
deterioration in water flows and water quality resulting from
agricultural and urban development. I firmly believe
that the passage of the Everglades National Park
Protection Expansion Act in 1989 was probably one of the pivotal
times in Everglades restoration, because it essentially allowed
for the use of all the information that had been
collected prior to that date and actually come up, or direct the
Corps of Engineers to come up with a concrete plan that would
allow for its restoration.The 1989 Everglades National Park
Protection and Expansion Act directed the National Park
Service to acquire 109,000 acres in northeast Shark Slough.
It also directed the US Army Corps of Engineers to make
modifications to roads and canals to restore the natural
hydrological conditions in Everglades National Park.Today
we've acquired 99% of those lands.
There's still a number of parcels that we're hopefully
working to get into, and at least purchase enough of the
real estate interest so we can affect the first stage of the
restoration process which is the project that involves the
construction of the one-mile bridge immediately adjacent to
us and the modifications to the remainder of the
roadway.Because of many constraints, mostly financial,
what started as an original recommendation of raising 10.7
miles of the Tamiami Trail ended with funding to build a one-mile
bridge and modifying the remainder of the roadway
corridor by raising and stabilizing it to the point
where the water level in the canal system next to Tamiami
Trail would permit increased flow south into the park without
damaging the adjacent roadway.We hope to be able to
discharge additional water from the Central and South Florida
Project into this canal system resulting in an increase in
water level approximately a foot higher that what it's currently
operating at and therefore allow for additional discharge.While
Dave has been working on the restoration for 30 years, the
first phase of the construction only began in 2010.
The schedule calls for the construction of the bridge and
the remainder of the road modifications to be completed by
the end of 2013.
This particular project actually is what I
consider a good, a really good first step.
Personally I would have preferred that we would have
made more modifications to the roadway that would have involved
a greater degree of bridging.
I think that as far as the future of the Everglades that
connectivity issue of marshes to the north and marshes to the
south and unrestricted flow has really great advantages in
restoring the ecosystem.Dave warns that reverting back to the
flow patterns of the past is not really a possibility.
The demand for the quantity of water needed for human
consumption is just too high.
So scientists and engineers are aiming to bring enough sheet
flow back to make the Everglades functional again.
But don't expect instant successwhat took decades to do
just may take decades to undo.We do believe that it is
a very wise investment largely because of the fact that it is
not just restoring an ecosystem; much of the changes that we're
actually envisioning for restoring the Everglades is also
going to serve as the basis for ensuring the future water supply
of Miami-Dade County.Just one small step along the way to
restoring the Everglades, the one-mile bridge on Tamiami Trail
is just one chapter in the Everglades restoration story.
Multiple stakeholders and agencies, including Miami-Dade
County, the National Park Service and the US Army Corps of
Engineers, continue to work together on numerous projects to
restore natural water flow, ecological connectivity and
habitat of the Everglades.
Perhaps years from now, visitors will be able to look out over
the wide expanse of sawgrass prairie
and see a much-restored Everglades.
They'll look out and understand just what Marjory Stoneman
Douglas was referring to when she called the Everglades the
"River of Grass."
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