By Michael E. Miller
By Ryan Yousefi
By Kyle Munzenrieder
By Sabrina Rodriguez
By Michael E. Miller
By Carlos Suarez De Jesus
By Luther Campbell
By Kyle Munzenrieder
When it comes to alien invaders threatening to wipe out a native species or two, overrun the Everglades, and undermine our fragile subtropical ecosystem, South Florida has bigger fish to fry. Literally. (Like the swamp eel.)
On the other hand, while this latest transplant may not single-handedly decimate local fish stocks and bring on ecological disaster, some fear that the cumulative impact of adding yet another foreign intruder -- especially one as ravenous and rapidly reproducing as the Asian snakehead -- could be more than the environment can handle.
It's "the house-of-cards hypothesis, that you put that one last card on there and you may have some sort of collapse take place," says Bill Loftus, a U.S. Geological Survey research ecologist at the Everglades Field Station outside Homestead.
Then again, maybe not. Paul Shafland, director of the Florida Fish and Wildlife Conservation Commission's Non-Native Fish Laboratory in Boca Raton, says hype is fueling a rush to judgment.
"If you look at the walking catfish, twenty years ago, they said that was going to be catastrophic. It wasn't. I'm not trying to minimize the effect, but not all exotics are inherently deleterious. And I think that's the presumption, that they are deleterious."
The snakehead, an air-breathing predator able to crawl from the depths and move across land, with a mouth full of teeth and a voracious taste for everything from tadpoles to small ducks, captured the salivating media's attention in July after it turned up in a four-acre Crofton, Maryland pond. Resident Joe Gillespie told the Baltimore Sun he caught "one the size of a golf bag," but it broke free from his light fishing tackle. "It was like something from The X-Files," he said.
In the absence of a repeat of the "Summer of the Shark," the TV cameras and news photographers gathered for a freshwater fish frenzy, the ideal antidote for a slow news day. Just when you thought it was safe to go back in the water ...
Soon enough, the snakehead, emblazoned with the new moniker "Frankenfish" by headline writers at no less than the Washington Times, catapulted to star in its own Top Ten List on David Letterman: "... Number seven: They love kids!"
And the snakehead seemed perfect for the part. The U.S. Fish & Wildlife Service offered information on its Website titled "Frankenfish: The Facts," which included specifics such as, "Parent snakeheads guard their young vigorously. One species (C. micropeltes) reportedly attacked, and in some instances killed, humans who approached the mass of young."
Details are hard to come by. Walt Courtenay, one of the two government scientists who spent nearly a year collecting information, mostly from Asian sources, for the proposed nationwide ban on all snakeheads, says he still has not been able to confirm the reports of human deaths. Shafland, in Boca Raton, snickers skeptically. Even though the snakeheads sport an impressive set of sharp, canine-shaped teeth, he can't picture the fish killing a person. In fact in most of Asia, it's the other way around. The snakehead is considered an excellent fish for eating, delicious in watercress soup, grilled with ginger, or fried up with rice noodles.
Killer or not, the fish is definitely aggressive. Fish-farm workers in Singapore must wear helmets and protective gear while harvesting the snakeheads, and Courtenay says an ecologist in Asia told him of an incident where a snakehead nearly castrated a man.
"I do know they have attacked people, but whether or not they have killed people is another story," Courtenay says. He adds, however, "if a giant snakehead killed somebody, I can guarantee you it was more than one. And usually, at least the young of that group, and I'm talking about fish that are up to maybe two feet in length, frequently feed in packs. And they are also known, in nature, to kill more fish than they will eat. It's the only record that I know of anywhere of any fish doing that kind of thing ..." He denied that the fish had bigger brains, and professed to be baffled at their behavior.
Nonetheless, while it may not be the monster some make it out to be, it's definitely the stuff of nightmares -- at least for some government scientists and ecologists contemplating the potential environmental havoc it could cause as it multiplies and eats its way across the country.
To them, it's hell on fins.
"The snakehead is a particularly voracious fish," says Ken Burton, spokesman for the U.S. Fish and Wildlife Service in Washington, D.C. "Once it's in a body of water it can, and it will, and it does eat virtually anything else that's in that water. It will eat all the other fish. It will eat small amphibians. It will eat small mammals, if it can get them, like ducklings. And over a period of time, you wind up with a waterway that is exclusively home to the snakehead."
Beginning in July the government began seizing all 28 species of the fish, including the varieties sold live and legally in Oriental markets in New York and Boston, as the poster spawn for the national "invasive species" problem. Interior Secretary Gale Norton called it "like something from a bad horror movie." She proposes a ban on importation of live snakeheads into the United States, and setting penalties of up to six months in jail and a $10,000 fine for offenders. (This past Monday, August 26, was the deadline for comment.) A resolution is expected soon.
Last Tuesday Maryland's snakehead task force huddled with scientists from across the country at the American Fisheries Society convention in Baltimore to come up with a proposal for tightening state regulations to avoid a repeat of the snakehead near-catastrophe in Crofton. That came just two days after state wildlife specialists began dumping a toxic cocktail in the pond, a mix of the chemicals diquat dibromide and glyphosate, to poison the pond's population of snakeheads -- along with everything else in the water.
But it turns out a snakehead population had been thriving in Tamarac for at least eighteen months before the first one reportedly snapped on an angler's hook in Maryland. Bob Newland of Sunrise snagged a two-footer in a residential pond on October 5, 2000. He mistook it for a native bowfin until he noticed a distinctive dark round spot rimmed in bright orange by the tail. Shafland identified it as a bullseye snakehead, a tropical relative of the northern snakehead that later caused the Maryland uproar.
It's an important difference because of the much greater natural range of the northern snakehead. That one can reportedly survive winter cold throughout most of the United States, even under the ice of frozen lakes and ponds. The bullseye's dependence on warmer water temperatures limits its range largely to the southern half of Florida. But that territorial restriction would not keep it from being included with the rest of the snakehead family on the "injurious species" list and subject to the proposed ban. In fact the Tamarac discovery was what pushed the federal government to begin the study and data collection that would form the basis for the ban, announced after the Crofton fish became a celebrity in July.
Actually it was already banned in Florida. Possession of live snakeheads is prohibited, and punishable by up to a $500 fine and 60 days in jail. It hardly matters; freshwater aquarium enthusiasts can buy live juvenile snakeheads over the Internet, and do. They arrive brightly colored and just a few inches long. But then, after the fish start devouring everything else in their tanks and growing like Jack's beanstalk on steroids, the owners start looking for ways to get rid of them. Instead of killing them, they turn them loose. That's what happened in Crofton, and that's what Shafland figures happened in Tamarac. Either that or someone looking to establish a stock of food fish released them.
"The way this fish moves is more associated with two legs, and not their own," he says. "I'm talking about man. The fish didn't swim here. We know it was people."
Four months after the first ones turned up in Tamarac, Florida Fish and Wildlife inspectors John West and Pat Reynolds found northern snakeheads alive and for sale at two Oriental food markets. They seized six at the P.K. Oriental Market in Pembroke Pines and eight in the Chung Hing Oriental Market in North Dade, charging both shops with possession of a prohibited freshwater fish. But these were different from the bullseye found in Tamarac, which meant those came from a different source.
Shafland tracked the fish through some culverts into local ponds on a golf course, then out into a major canal just east of the Everglades. In just a couple weeks of electrofishing -- coursing electric current into the water to stun the fish -- researchers pulled close to a hundred snakeheads from the canal. Since then they've found hundreds more.
Finding it there meant the fish was established, reproducing, and on the loose, free to move almost anywhere in South Florida through the maze of interconnected manmade waterways. And there is virtually no way of stopping it.
"Down here, everything is wide open and connected," says ecologist Loftus. "So that by the time a fish gets into the canal system, or by the time it penetrates from the canal system into the Everglades, it's pretty much a done deal. There's nothing you can do about it."
Which, at least so far, seems to be okay with almost everyone. The snakehead is merely one of the 32 nonnative freshwater fish crowding the South Florida ecosystem. Even the canals they call home are manmade intrusions on the natural environment. Basically there's an abundance of exotic immigrants battling among themselves in an artificial arena. Not a big deal. At least, not yet.
The real worry is over the Asian swamp eel, another air-breathing predator able to move across wet ground like the snakehead that's inching into Everglades National Park. Unlike the other exotic fish that may make incursions into the shallow water of the swamp but either die or retreat into the deeper, warmer water of the canals when cold comes, the eels could take up permanent residence in the 'Glades.
"These eels, because they can burrow into the substrate and survive cold and drought underground, they may, once they get into the 'Glades, they may be there year-round. So they have the potential to invade a much larger area and get into the interior area a lot more than some of these other invasive species or nonnatives," says Leo Nico, the U.S. Geological Survey research biologist who was the first to discover the swamp eels in Florida, outside Tampa, in 1997. By the time he stumbled upon them, that population already extended through about 30 kilometers of canals there. About the same time, students caught some baby eels in a North Miami canal for the first time, only to find that the colony stretched through some 50 kilometers of waterway. In December of 1999, Nico says, the third known eel population turned up near Homestead and the entrance to Everglades National Park. Nico suspects all three may have been thriving for a decade before anyone noticed.
Researchers are long past any hope of eliminating the swamp eels. They spent six months electrofishing in one of the canals near the Everglades, and removed 1400 eels. "It probably didn't really put much of a dent in the population, to tell you the truth," Nico says. Still they plan to try again, to test electrofishing as a means of controlling the eel population.
There's still no telling what the impact of the eels will be. They gobble up almost any fish, frog, worm, or crayfish small enough to fit in their mouths, with a fondness for tadpoles. But they can go for weeks without food. All are born female, with some transforming into males. They reproduce year-round. And they're spreading.
At the very least, the eels, the snakeheads, and all the other invader species are occupying an environmental niche that might have been occupied by a native species, using up limited resources. At the worst, they could force some native species into extinction, disrupt the food chain, and trigger a catastrophe. No matter what, it all adds up.
"The real misconception that a lot of people have," says Jim Williams, head of the biodiversity branch at the Florida Caribbean Science Center in Gainesville, "is that it's like adding two chemicals together and getting an explosion. Only in this case, you add fish to water and it may be five years, ten years, maybe fifty years before you get the explosion. So basically, you're dealing with a biological time bomb. And it's sitting there ticking.
"This just represents one more nail in the casket, if you will," he says. "Is it a small finishing nail, or a large tenpenny nail, or a railroad spike? I don't know."