麻豆传媒

IT鈥橲 5 am. We pull on muddy jeans, confront a horde of hungry insects, and
pour a can of beans for breakfast. Then we paddle up a narrow channel, curtained
with Spanish moss and poison ivy, and pull the traps set late the night before.
If we鈥檙e lucky, one of the nets contains a turtle, restless after a night of
trying to escape the funnelled hoops. We slog it onto shore, heave it onto
portable scales, and then flip it on its back to draw off a few drops of blood
from the snakelike tail.

But fieldwork doesn鈥檛 always resemble mud wrestling, even for wildlife
biologists. One evening, our collection site is one of the finest Cajun
restaurants in New Orleans, where a jacket and tie are the appropriate attire
and the only vegetation is the 300-year-old live oak in the garden. Instead of
setting nets for our sample, we make a reservation for two.

After serving the wine, our waiter arrives with a porcelain bowl filled with
thick, dark broth. When he turns his back, we scoop a brown cube of meat from
the turtle soup au sherry and drop it in a blazer pocket lined with plastic. Our
newest genetic sample will join a freezerful of turtle purchased in restaurants,
seafood markets, turtle farms, rendering plants, and even on the Internet.
Later, back in the lab, we鈥檒l analyse its DNA to discover whether the meat came
from legally harvested turtles or from endangered species protected by law. Our
sampling may also uncover a sleight-of-hand we call the 鈥渕ock turtle
syndrome鈥濃�攁 practice that could alter the conservation prospects of not
just turtles but other overexploited species as well.

One of the most prized鈥攁nd feared鈥攖urtles in the channels,
streams and oxbow lakes of the South is the enormous alligator snapping turtle.
Though they are found in every major river between Florida and Texas, you can
live along the Mississippi, the Apalachicola, the Perdido, the Suwannee or the
Pearl and never see one. The alligator snapper鈥檚 furtive habits contribute to
its dark esteem, as do its powerful jaws: legend has it that the alligator
snapper can amputate a man鈥檚 hand with one bite. That鈥檚 a bit of an
exaggeration, but not much of one. A few years ago, one of the beasts nabbed the
thumb of our colleague Paul Moler, a herpetologist with the Florida Fish and
Wildlife Conservation Commission. How did it feel? 鈥淣ot too bad,鈥� he says. 鈥淒id
you ever get your thumb closed in a car door?鈥� Fortunately for Moler, he was
able to poke a screwdriver into the crook of the turtle鈥檚 jaw and wedge himself
free. It was also fortunate that Moler was caught by a 5-kilogram juvenile.
Full-grown males can weigh more than 90 kilograms, with a metre-long shell as
tough as a beer keg. There aren鈥檛 many predators that can challenge this
monstrous turtle.

Except people. Inside the carapace is a tubful of red meat, making a snapper
irresistible to hunters armed with such simple traps as trotlines鈥攍ines
with multiple hooks鈥攁nd hoop nets鈥攖unnel-like nets closed at one
end. It takes a long time for an alligator snapper to reach the size of a
manhole cover, but these river-dwellers may reach enormous ages, perhaps 100
years or more. Such longevity means that alligator snappers, like whales and
other late-bloomers, may not be able to withstand intensive harvest. With a few
traps, a small boat and knowledge of turtle habits, a trapper can quickly
deplete a local population. Al Redmond, who worked the Flint River in Georgia
during the 1970s, reported to biologist Peter Pritchard that he could harvest
1000 pounds鈥�450 kilograms鈥攐f alligator snappers per day. At that
rate, an entire river could be emptied of large turtles in a year.

Many Southern states, faced with decreasing snapper populations, closed down
trapping in the 1980s. But Louisiana continues to permit commercial
exploitation, and there is anecdotal evidence that alligator snappers are
poached in Alabama, Florida and Mississippi for the market in New Orleans. Could
we prove it?

One October morning at dawn, we head up the Santa Fe River in northern
Florida with Moler. On the banks, sweet gum and saw palmetto trees squeeze their
way through the formidable front line of bald cypress. Sliders and
cooters鈥攃ommon river turtles鈥攂ask on fallen trees, and an alligator
slides into the river just below our first trap.

Our first three nets are empty, though something has stolen the fish-gut bait
from one. As Moler handles the fourth trap, two alligator snappers lift their
ghastly heads to breathe. Crouched in the boat, Moler spots two more turtles
below鈥攆our alligator snappers have spent one restless night in that trap.
The largest of the four weighs in at 45 kilograms, and its shell is more than 40
centimetres long. With a kilo of turtle meat retailing for $20, this haul
could have brought us $500 if we were poachers. But all we take are
measurements and a few drops of blood.

Our DNA analysis of samples like these, many collected by colleague Steve
Santhuff, has revealed that most river systems from Florida to Texas hold
genetically unique populations, isolated for tens of thousands of years. That
confirms the long-held suspicions of naturalists who knew that alligator
snappers鈥攗nlike their closest relative, the common snapping
turtle鈥攔arely venture onto land or into salt water. If the turtles are
hunted out of a river, they won鈥檛 be replenished by migrants from other rivers.
That river鈥檚 distinctive genetic diversity, the mainstay of evolution, will
disappear forever.

But the same isolation that threatens local populations makes it easier to
track poachers. Alligator snappers can be legally harvested only from Louisiana
rivers, so only turtles carrying the Mississippi River genotype should be on
sale in the markets. It was this observation, plus reports of poaching in other
states, that prompted us to extend our genetic studies from the Southern bayous
to the restaurants and turtle markets of Louisiana.

In a total of 34 turtle-meat samples, we found just one alligator snapper.
That鈥檚 not necessarily good news鈥攊t could mean that the big turtle has
been hunted to near extinction. Most of the meat we bought in Louisiana was from
common snapping turtle, which has a wide distribution in North America,
stretching from Mexico to eastern Canada. A few samples matched the Florida
softshell turtle, which is heavily harvested for Asian markets. Our worst
fear鈥攖hat sea turtles were still in the trade after a quarter-century of
protection鈥攆ortunately turned out to be unfounded. But our most surprising
result was that a quarter of the meat sold as turtle wasn鈥檛 turtle at all.

It鈥檚 not the first time other meat has been passed off as turtle. Green sea
turtle was the height of fashion for diplomatic dinners and society banquets in
Victorian England. Not everyone could afford this luxury, though, and mock
turtle soup鈥攃ommonly made of veal鈥攂ecame popular in middle-class
restaurants and dinner parties. So popular, in fact, that Lewis Carroll gives
the Mock Turtle a cameo appearance in Alice in Wonderland. As depicted
by illustrator John Tenniel, it is half floppy-eared calf, half teary-eyed sea
turtle.

Here in the New World, we have our own mock turtle鈥攖he American
alligator. Alligators are once again abundant in the United States and
protective measures have been lifted. Their meat, now available from farms and
wild hunts, brings a lower price than turtle. As turtles become harder to find,
our DNA tests show that some butchers are turning to 鈥榞ator meat to fill the
demand.

This reptilian fraud made us take a second look at other market studies.
Genetic researchers Scott Baker and Steve Palumbi found dolphin meat being sold
in Japan as more highly prized whale meat, which retails for up to $500
per kilo. Even stranger, five of their 鈥渨hale鈥� samples matched horse
DNA鈥攏ot a bad mark-up for meat usually destined for dog food. Rob DeSalle
and colleagues at the American Museum of Natural History in New York found
Mississippi sturgeon roe in tins labelled as the rarer, and pricier, Beluga
caviar. And seal penises, which can fetch up to $600 apiece on the Asian
aphrodisiac market, often turn out to be genitalia from domestic cattle and wild
dogs. (Bull pizzle has to be carved to pass as a pinniped sex organ.) About 25
to 30 per cent of these luxury items, from turtle meat to seal penises, are
falsely labelled. We refer to this substitution of a commoner wildlife species
for a scarcer, higher-priced one as the mock turtle syndrome, in honour of
Carroll.

At first glance, it seems that this replacement could help ease the pressure
on overexploited species, allowing them to recover as other animals are
harvested. Not so, insists fisheries biologist Dan Pauly at the University of
British Columbia in Vancouver. 鈥淭he notion of relieving pressure is absurd. It
assumes that there is a fixed demand. But there is enormous elasticity in the
market. If people have more money, they will buy more,鈥� he says. In the end,
鈥渢here is no market magic鈥� to bail out endangered species.

In fact, the mock turtle syndrome clearly has big disadvantages for
conservation. A fishmonger who will sell horsemeat for several hundred dollars a
kilo isn鈥檛 likely to baulk at including an endangered species either. Baker and
Palumbi have found five endangered baleen whale species, including the enormous
blue whale, in the markets of Japan. In July, 15 sea lions were found dead near
a tourist resort in the Galapagos. Their genitalia had been removed, presumably
for later sale. And these aren鈥檛 the only marine species in danger. Pauly has
documented a persistent pattern of fishing down the marine food web: after
prized top predators are hunted out, fishermen turn to increasingly smaller
prey, depleting coastlines of marine life.

If even such high-profile species as marine mammals fall prey to the
insatiable hunger of the marketplace, how can we expect inconspicuous turtles to
fare any better? Alligator snappers are tough, able to break broomsticks in a
single snap of their jaws, but they can鈥檛 escape a persistent set of traps or
series of trotlines. The market is relentless, and the mock turtle syndrome
enables vendors to play an endless shell game.

On our last trip to Louisiana, we visited a shop on the outskirts of New
Orleans, not far from the Mississippi. A man in a white apron told us it was
illegal to sell alligator snapping turtle in the US. The turtles were just too
rare. Standing in front of a pen of common snappers, he handed us a kilogram of
fresh meat.

It was the only alligator snapping turtle we found.