December 20, 2014
Bookmark and Share Email this page Email Print this page Print

Might Our Ecosystem Crash?

A look at the dangers, as climate change takes its toll

Rising tides actually could mean drier Everglades going forward as climate change reshapes our landscape.

Rising tides actually could mean drier Everglades going forward as climate change reshapes our landscape.

 

When a ranger from glacier national park tried to paint her park as the poster child for climate change, Gary Bremen thought: au contraire. A ranger at Biscayne National Park—which has a high point of just 6 feet above sea level—Bremen insists that few national parks will be affected the way his will. Glacier National Park may lose its glaciers, but Biscayne National Park may cease to exist. Regardless of whether you believe the warming of the earth is caused by human activities or other uncontrollable factors, there is a well-documented record of increased median temperatures over the past two decades. That spells big trouble for low-lying areas like South Florida.

Last May, the planet reached an ominous milestone as researchers noted the amount of carbon in the earth’s atmosphere had reached 400 parts per million. The last time this happened was 5 million years ago, when mastodons ruled North America and global seas were 25 meters higher than they are now.

Indeed, if scientists had marked this milestone with a party, the ice sculpture on the buffet may have melted. Which is exactly what is happening to our glaciers and polar ice sheets. In the last 100 years, the tidal research station on Key West has seen the ocean surge almost 9 inches. In centuries before, the oceans likely gained only an inch per 100 years. Scientists predict the rate of rise will only continue to accelerate as the planet continues to warm.

And as the ocean surges, life in balmy Florida will change forever. Swallowed up in one slow, salty gulp will be some of our region’s most beloved features. Scientists warn that they can’t really predict how fast sea levels will rise, or whether some species will be able to adapt. But they do fear for certain species, and they can offer predictions for how they think things may progress. The list below is the product of that: nine evidence-based predictions on what will slip away as the ocean slowly takes back the peninsula.

 

Coral Reefs

Biscayne National Park is the only unit of the National Park System that’s almost entirely underwater. Every year thousands of visitors snorkel and dive through the park’s vibrant community of coral reefs. But these reefs are facing an uncertain future. According to the National Oceanic and Atmospheric Administration (NOAA), ocean temperatures have increased 1.3 degrees Fahrenheit since the late 1800s, and scientific studies show that coral reacts poorly to warming oceans. One study done by leading ocean researcher Ove Hoegh-Guldberg found that all of the seven largest coral-bleaching events since 1979 could be attributed to warming waters.

“We have a pretty good idea of what will happen to corals as ocean temperatures begin to rise, because we’ve seen these bleaching events due to warm water before,” says Larry Perez, a science communications specialist at Everglades National Park. “In 2005, they [researchers] noticed a significant amount of coral loss in the wider Caribbean, and as the ocean continued to warm up—we had several months of continuously warm ocean temperatures—it looked like South Florida was going to suffer a loss, too. But in early August, Hurricane Katrina passed by as a Category 2 hurricane before it made its fateful journey to Louisiana. And when it did, it brought with it from the Atlantic an upwelling of cold water that washed over the reefs and basically saved them.”

In particular danger are staghorn and elkhorn corals, which are already listed as threatened species by the Endangered Species Act. Since 1980, populations of staghorn and elkhorn corals have been plagued by disease and bleaching. NOAA estimates that as much of 90 to 95 percent of the population has been lost, mostly due to climate change-related causes.

 

Cape Sable Thoroughwart

With a light purple, disheveled-looking pompom for a blossom, and nondescript green leaves, Cape Sable thoroughwart may be the most unassuming plant of all time. But it is also probably the first plant in Florida that will be lost planet-wide due to sea-level rise. Found only in Monroe County—which includes the Keys and the chunk of the Everglades nestled in the extreme southwestern tip of the state—along parts of Florida Bay and in the Everglades, Cape Sable thoroughwart lives almost exclusively in the buttonwood embankment, a coastal ridge that sits just a half-meter above sea level.

“Increased salinity and/or inundation will lead to the loss of Cape Sable thoroughwort as sea level rises into those low-lying communities,” says Jimi Sadle, a biologist for Everglades National Park. But, he cautions, it’s hard to know exactly when such inundation would happen, so he’s reluctant to put a timeframe on such an event. Most plants that will be inundated by saltwater will be lost only regionally. Some may move north, while still others may continue to thrive in inland tropical areas in Central or South America. Cape Sable thoroughwart, however, grows only here. Its loss from South Florida would mean it would be gone from the world forever.

 

Our Grandfathers’ Everglades

Somewhat ironically, as our coasts become flooded with seawater, our inland areas are forecasted to become hotter and drier. Based on a prediction from the Intergovernmental Panel on Climate Change (IPCC), South Florida—and Southwest Florida in particular—is predicted to receive 10 to 20 percent less precipitation annually by the end of the century.

This means more incidences of fire, and tougher times for orchids and airplants. But changes in climate will also likely help invasive species thrive.

“The plants we work with have really wide ecological envelopes, so they can thrive in a wider range of environments,” says Melissa Smith, Ph.D., an ecologist who monitors invasive plant species for the U.S. Department of Agriculture. “With climate change, it’s predicted that we’ll have more catastrophic events, and invasive plants really recover well and are able to gain a foothold faster than many native species.”

Which means there may be a day when you cannot see the wilderness as our forefathers saw it: lush, healthy and teaming only with native plants.

 

Sawgrass Prairie

Mangroves are on the move in South Florida, replacing areas that were once freshwater sawgrass prairies. “I’ve been here 25 years, and I’ve absolutely seen the mangroves moving inland,” says Larry Richardson, a biologist at 10,000 Islands National Wildlife Refuge and the Florida Panther National Wildlife Refuge. “There’s certainly a change going on. We’re getting more and more salt in these areas, and you can tell that because you see mangroves moving in.”

A 2011 study found that from 1927 to 2005, mangroves in 10,000 Islands increased their range by 1,878 hectares. Much of this gain came at the expense of sawgrass prairies, which are a prime habitat for wading birds, marsh rabbits and alligators.

“I can definitely imagine a day when there is no sawgrass prairie in Everglades National Park,” Perez says. “That doesn’t mean that it will disappear completely, it may shift northward, but there may be a time when it’s no longer within the bounds of the park.”

Where the sawgrass prairie goes, so will the animals that live within it. Richardson worries that we’ll start to see a decline in wading bird populations, especially the American bittern and the least bittern. “These two are specific to grassy marsh habitat. They truly look like a blade of grass when they’re hiding. I don’t think they’ll be gone for good, but I think you’ll have to look elsewhere to find them.”

 

Pieces of Our Collective Cultural Heritage

During Hurricane Sandy, a four-block section of historic Highway A1A in Fort Lauderdale almost washed away. The confluence of a full moon, seasonal high tides and a storm surge proved too much for the manmade creation. Just a few miles south, the historic Cape Florida Lighthouse on Key Biscayne appears to inch closer to the shoreline with each passing year. Lighthouse keepers’ logs show that at one point it was 500 feet away from the shoreline. Now the Atlantic is all but nibbling at its toes.

While we can fortify—or even try to move—these structures, within the borders of Everglades National Park there’s a cultural resource that may be more complicated to save. Ancient people—whom National Park Service archeologist Dr. Margo Schwadron likes to refer to as the Glades People—built complex shell middens throughout the park’s boundaries. Schwadron and her colleagues are still trying to figure out exactly how the mounds were used. Unlike many shell middens in the world, which are simply the giant garbage heaps of shellfish-consuming peoples, the middens in South Florida were clearly purposeful in design. There are ridges and valleys in patterns that replicate from one midden to the next. Schwadron has theories on how these ridges and valleys were used—it’s what she did her dissertation on—but she’s still not totally certain. Unfortunately, the mounds may be lost before their mysteries can be uncovered.

“You can see where the embankment is being carved out on the Turner River Mound,” Perez says.

Schwadron agrees, but says that actually adding reinforcements to the eroding mounds would prove complex, because most of the mounds sit in “high-energy” areas. Meaning, they’re pummeled by in-and-outgoing tides, so not just any reinforcement will do. But without buffering them from the rising tides, an entire culture’s history may be lost.

 

Beaches

OK, to be fair, there will always be beaches somewhere. However, the beaches we currently know and love— think the lovely City of Naples beach and Fort Myers Beach—may change dramatically.

“We certainly won’t lose all beaches and all beach-dwelling animals,” says Chris Bergh, the South Florida conservation director for The Nature Conservancy. “A beach can move upland, but if there’s nowhere for the sand to go, there’s nowhere for the beach to move.”

When humans “harden” the area around a beach—meaning build concrete structures, like retaining walls and hotels—a beach loses its ability to move. The energy of the waves pushes sand closer and closer to the things we’ve built until, finally, something has to give.

“We’re really most concerned about the built-up beaches with seawalls along them,” says Jim Beever, a principal planner with the Southwest Florida Regional Planning Council. “That’s Captiva, Naples, Fort Myers Beach. Sanibel really doesn’t have the same problem because it doesn’t have hard concrete features built parallel to the water. There’s a better way to live with beaches than how most people are currently doing it.”

 

Flood Insurance

The National Flood Insurance program is $24 billion dollars in debt, and there’s no real end in sight. Recent legislation in Congress would delay rate hikes for four more years, but politicians on both sides of the aisle are concerned that the National Flood Insurance Program is literally going to drown in its own debt.

“If something isn’t done to reduce that debt, there may be a point in time when the program is no longer viable,” says Joe Williams, an insurance industry specialist with more than 48 years of experience. “Until the (Bigget-Waters) bill was passed two years ago, rates were artificially low. But if they do these rate hikes, it will be really hard for those living in flood-prone areas.”

Essentially, the National Flood Insurance Program, which sits under FEMA, has been inundated with claims from Hurricane Katrina followed by Hurricane Irene followed by Super Storm Sandy. With forecast models predicting more severe storms as a byproduct of climate change—along with increased storm surges due to sea level rise—things will probably get worse, not better, in the future. Could this mean the end of flood insurance as we know it? Probably not, but it could become a lot more costly.

“Eventually, I think American taxpayers who don’t live in flood-prone areas are going to start asking, ‘Why are we continuing to finance this?’” Williams says.

 

Key Largo Woodrats and Key Deer

During the Wisconsin Glaciation period, a land bridge formed between mainland Florida and the Keys. Animals migrated to the Keys, and then as sea levels began to rise, they were stuck. Over time, these creatures evolved into their own separate subspecies.

But as sea levels continue to rise, these creatures are facing a tough future. Both Key deer (which are a subspecies of whitetail deer) and Key Largo woodrats (which are a subspecies of the Florida woodrat) are listed as endangered. Both are found only in the Keys, in areas that climate models show being mostly underwater in the next century. “But even before that, the Key deer especially are limited to where they can find fresh water. Their freshwater supply will probably be affected long before the island is gone,” says Steve Traxler, a senior biologist for the U.S. Fish and Wildlife Service.

These two species represent an interesting ethical minefield, which scientists may have to navigate if current climate projections prove accurate. “Assisted migration,” or the idea of helping plants and animals move into new habitats, is a topic that’s making its way into more and more conversations about climate change. A few decades ago, the topic would have been generally unthinkable, as ecologists and biologists generally try to be as un-interventionist as possible. However, in a case like the Key deer, where a subspecies may be lost without the help of humans, many scientists find themselves reconsidering their formerly un-interventionist positions.

“The climate is always changing. It’s changed many times in the past. But in the past, species largely had a natural landscape over which they could redistribute themselves,” explains Dr. James Watling, an assistant scientist at the University of Florida. “Humans have drastically changed that landscape. Connectivity is drastically lower than it’s ever been in the past.”

Essentially, there are concrete barriers in the form of cities and highways barring the path of migrating panthers or marsh rabbits and even plants. The only solution many scientists can see is to physically help them move.

But it’s complicated. Watling worked with colleagues at the United States Geological Survey to map out models of which areas might be agreeable in the future to 26 South Florida vertebrates on the threatened and endangered species list. For the Key deer, the mainland South Florida ecosystem appeared to be hospitable—except for one problem: The Key deer are likely to interbreed with the whitetail deer, meaning the subspecies would eventually be lost.

There’s another place that the Key deer might also be able to go, and that’s Andros Island, in the Bahamas. Moving them across international lines, however, causes other challenges. Getting multiple nations on the same page with how to best manage an endangered species seems fraught with difficulty. Which country would assume the role of managing the species? What if one country didn’t agree with the other’s management decisions? It’s a bad solution at best. Unfortunately for the Key deer—marooned on a drowning island—it may be their only solution.

 

See You Later, Alligator?

The American alligator is one of the United States’ best comeback stories. From 1860 to 1970, more than 10 million alligators were slaughtered in South Florida, bringing them almost to the brink of extinction. Today, they lounge in many drainage ditches, retaining ponds and natural lakes in Lee and Collier counties. But because the American alligator is primarily a freshwater species, its glory days may be limited. As sea level rise brings saltwater further inland, alligators may lose prime hunting ground.

Florida Fish and Wildlife Conservation Commission Sea Level Rise Coordinator Whitney Gray says although she’s seen alligators survive in saltwater areas, her largest concern is the competition they may face from saltwater crocodiles. Traditionally, saltwater crocodiles have been the apex predator in saltwater, while alligators have ruled freshwater. As saltwater and freshwater merge, so too will the domains of these two reptiles.

 

Winners of Climate Change

This story may paint climate change as all doom and gloom. While certainly a warming planet has significant negative ramifications, there are some surprising winners in the climate change game. Here’s a look at the species that might do well in the coming century.

Seagrasses: When carbon dioxide mixes with water, some of the carbon dioxide forms carbonic acid. This makes the ocean more acidic. Ocean acidification is one of the byproducts of climate change, and that’s a big problem for a lot of ocean-dwelling species. Seagrasses, however, love the excess carbon dioxide. In a 2008 study, scientists found that the grasses growing near an underwater volcanic vent that released carbon dioxide did well. However, the calcifying epiphytes that lived on the grasses suffered.

Mangroves: These salt-tolerant plants are set to move both into marshy coastal areas and northward as temperatures rise and coastlines are inundated with saltwater. While this is bad news for the marshes, it could be good news for reducing carbon dioxide levels. Mangroves are incredible carbon dioxide sequesters, absorbing 10 times the amount of carbon dioxide than a similarly sized deciduous forest.

Saltwater Crocodiles: Technically, as ocean temperatures rise, saltwater crocodiles should increase their range. Perhaps even dramatically so. “Based on modeling we did, we could potentially see hospitable climate for saltwater crocodiles up the Florida coast, into Georgia and maybe even the Carolinas,” says Dr. James Watling with the University of Florida. However, that doesn’t mean we’ll see a giant uptick in the crocodile population. Almost all of the area projected to be hospitable to crocodiles is already dense with human development. It’s unlikely that crocs would find much in the way of suitable nesting sites throughout most of it. And, Watling adds that some climate projections show that South Florida could actually become too hot for crocodiles.

—ACS

 

What Does ThisMean for Me?

If this is all sounding pretty ominous and you want to know what your backyard will look like in 30, 50 or even 100 years, several groups have created tools to help you do exactly that. The Coastal Resiliency Network, which is a nonprofit partnership between The Nature Conservancy, NOAA, The University of Southern Mississippi and a few other organizations, has a comprehensive online map that shows predictions for 1, 2, 3 and 4 feet of sea level rise.

While it’s very hard to predict the actual rate that seas will rise—and past models from the IPCCA appear to have been too conservative—most climate scientists agree that in the next 100 years, seas will rise between about 1.3 to 2 feet if we take drastic measures to curb greenhouse gas emissions and between about 2.3 to 4 feet if we continue in our current path.

To see what this looks like in your backyard, visit coastalresiliance.org, click on the map of the United States, zoom in on Southwest Florida, and then add 3 feet of sea level rise. On the right of the map, the button that says “basic” will let you change to a street map of the area. Zoom in far enough and you’ll see that parts of Fort Myers Beach, Marco Island and even bits of Naples are in for a bit of a soak.

—ACS

 

Add your comment: