Return of the Native
A Natural History of Two Species
MICHAEL W. FINCHAM
Naturalist Willem Roosenburg has been catching and often recatching terrapins in creeks off the Patuxent River for 22 years. He is holding a female terrapin that he’s caught before as part of a long-term study documenting some of the threats to her survival.
MAYBE YOU CAN GO HOME AGAIN, at least if it's summer and home is Southern Maryland. It's early June and Willem Roosenburg is heading out towards the river he grew up on. He's steering a small skiff along Washington Creek, a short, muddy-looking branch of the Patuxent River. The 49-year-old biologist is back from his teaching job at Ohio University and he's doing what he did first as a kid, then as a graduate student: he's looking for turtles.
It's the first day of his summer turtle-catching season, and under his wide-brimmed hat, Roosenburg sports a round face, a goatee, and the smile of a big kid let out of school. As he glides the skiff up to a fyke net, one of several he set out two days ago, he immediately starts an introductory lecture to a boatload of four assistants. Out on the river, he's still playing the teacher. Two of his assistants are undergrad students from the University of Maryland where a diamondback terrapin named Testudo is the school mascot. They've heard the lecture before and begin hauling the net aboard.
His other assistants are hearing his talk for the first time. They're field biologists just arrived from faraway Myanmar, sent here for training by the International Turtle Alliance and the Wildlife Conservation Society, organizations alarmed by the possible extinction of turtles in Asia. Back in Myanmar, naturalists are organizing conservation and restoration programs focused on the Burmese roofed turtle. This is the biologists' second day in Southern Maryland and their first experience with emptying fyke nets.
The fyke net, a long, baglike cylinder, lies submerged in shallow water with several hoops breaking the surface like the humps of a small whale tethered to the shore. In the belly of this whale Roosenburg expects to find a number of diamondback terrapins, the species he's been monitoring along this river for more than 20 years now, a species that's been crawling around rivers like this for longer than humans have been walking on two legs. Turtles shared the earth with dinosaurs and somehow survived the mass extinction that wiped them out. Sometimes the race is to the slow.
"Let's show you how to get these turtles out of the net," Roosenburg tells his Myanmarese assistants. As the net comes out of the water, several diamondbacks are clawing their way along the sides, their heads sticking through the net and swiveling on narrow necks like periscopes scanning for enemy ships. Most of them lose their grip and tumble backwards.
"You first go to the back of the net," Roosenburg says, "and you need two people." His helpers, Khin Myo Myo and Kyaw Moe, grab the back end and begin shaking out the net. A small pumpkinseed sunfish and several perch are soon flopping along the bottom of the boat. And crawling among them are seven terrapins.
Roosenburg picks up one of the larger terrapins, a female with a bright yellow bottom and a distinctive diamond pattern on the back of its shell, and holds it out. "Somebody want to hold her?" he asks. "She's a female. You can actually feel the eggs inside it, little hard round things that dimple." Myo Myo takes the turtle and hesitantly inserts her fingers under the shell. "I think she's probably 30 years old. And she's marked," he says pointing to notches along the rim of her shell.
He put those notches there himself when he first caught this same turtle years ago, and those notches tagged her with a numerical ID that will stay with her the rest of her life. "This one's ID is 1R2R4R11R9L," he says, reading first the right side of her shell, then the left.
BIOLOGIST WILLEM ROOSENBURG has spent 22 years studying terrapins on the Patuxent. This summer he had help from researchers from Myanmar and students from the University of Maryland. [more]
On this bright June morning, Roosenburg and his crew pick 24 terrapins out of five fyke nets along two muddy creeks and 18 of them are clearly marked recaptures. They also find a number of blue crabs and fish, including a hogchoker, which unleashes a lecture on the nomenclature of local species. The crew gets lessons on bagging terrapins and numbering the bags according to location. Field notes on time and date and site of each capture go into a yellow notebook.
This mark-and-recapture study is one of the reasons biologists come this far to work with Roosenburg. For more than two decades, he's been catching and notching turtles along these creeks. He's doing natural history, a traditional form of science that features time-consuming field work, close observation, and obsessive record keeping, all aimed at a fulsome description of organisms and their survival over time in their natural habitat.
In his records are some worrisome signs. Roosenburg has not been catching as many turtles as he did just 10 years ago. Is Maryland's diamondback terrapin, like the Burmese roofed turtle, rapidly becoming an endangered species while hardly anyone's watching?
Long-term records that track population trends are rare now in estuarine biology. They're rare because they're rarely funded. For his turtle work on the Patuxent, Roosenburg has been funded well for only seven of 22 summers. His research has been largely self supported. Are natural historians like Roosenburg also becoming an endangered species?
Natural history may be dying out, much like some of the animals it once described in such loving detail. That, at least, is the argument put forward by a number of scientists and philosophers of science who would revive the discipline. They point to the encroaching popularity of newer fields, such as cellular biology, molecular biology, systems ecology, and mathematical ecology. Scientists in those fields are seen as rising stars working in cutting-edge research, a perception that leads to generous funding for newer fields and skimpy support for "old-fashioned" fields like natural history. Universities, of course, have a natural tendency to follow the money, hiring scientists in hot fields in hopes of bringing in larger grants that will help pay the bills. It's one of their survival strategies.
The diamondback terrapin is the only North American turtle that lives exclusively in the brackish waters of estuaries, bays, and salt marshes. The carapace of each animal has markings as unique as a zebra's stripes or a human's fingerprints and the pattern on its shell gives the diamondback its name.
The subspecies found in Chesapeake Bay, the Northern diamondback terrapin, grows larger than any other diamondback. Males can reach six inches, while the generally larger females may grow up to nine inches. Terrapins primarily eat mollusks such as snails, clams, and mussels, their strong, sharp beaks allowing them to break their prey's hard shell.
Though terrapins can live longer than forty years, very few of the eggs laid actually survive the first year. Predators such as foxes, raccoons, and skunks prey on eggs and juveniles. As diamondbacks mature, threats largely shift from natural predators to human-induced challenges, such as fishing pressure and damage from boat propellers.
The results of this trend were spelled out in pessimistic detail several years ago in "The Impending Extinction of Natural History," an essay published in The Chronicle of Higher Education. As universities fill up with specialists in the new fields, those specialists are not likely to hire junior faculty in older fields like natural history. A cascade of decline can follow, similar to declines seen when wildlife populations are driven out of their breeding grounds. "The natural historian has been pushed to the margins of academe." wrote the co-authors of the essay, David Wilcove, a conservation biologist, and Thomas Eisner, a pioneer in the field of chemical ecology. "The de-institutionalization of natural history," they write, "looms as one of the biggest scientific mistakes of our time."
Natural history today is only seen as useful if the animal it studies is useful. The blue crab supports an important commercial harvest in Chesapeake Bay, and so does the striped bass, and once upon a time, so did the native oyster — all species that have been and still are well studied. But what's the economic payoff from natural history on species like the diamondback terrapin? When Christopher Norment, an expert on the Harris sparrow, applied for a job at a small university, he got the tough question about natural history: "What good is your research?"
Another rap against natural history is that it seems to offer no "theoretical fix," according to Mark Sagoff, a philosopher and critic of theoretical ecology. Science that promises to deliver (eventually) a theory about how a whole ecosystem works is more likely to get funded. System-wide theories seem more "useful" for managing complex ecosystems than detailed descriptions of an individual animal — unless that animal is a force in how the system functions or malfunctions. "What we really have to do," says Sagoff, "is find out how terrapins are an umbrella species or a keystone species or a nail-in-the-coffin species. Or any metaphor you like." Then terrapins might be worth saving — along with the natural historians who study them.
Such seems to be the naturalist's dilemma in the contemporary science climate: How do you run a long-term, largely unfunded study of a low-profit, low-theory animal? And what good, after all, is your research?
Roosenburg is lecturing again, and this time everybody is listening. He and his assistants and five bags of turtles are crammed in a small field lab, getting ready for their first data-recording session of the season. Their makeshift lab is a small dark room in a red brick outbuilding that might have been a horse stable once upon a time.
The lab sits on a large farm estate that holds a number of barns as well as two small cabins where the student assistants bunk and a creekside house where Roosenburg and his family spend their summers. The whole setup comes with a low rent to Roosenburg and his crew, thanks to the good will of a long-time landowner who likes the idea of a local scientist doing long-range natural history on a native species.
That's part of the secret behind Roosenburg's success in running a long-term study of a low-profit animal: he uses low-cost lab space and low-cost help like biologists from Myanmar and undergrad students from Ohio University and the University of Maryland.
His students are eager, but untrained. Hence all the lectures. "You're looking at a turtle that is probably twice as old as you guys are," Roosenburg tells his assistants, holding up a large female that was at least 15 to 20 years old when he first caught her in 1988. For this turtle and for every other one that comes out of his nets, he wants a dozen data points recorded, including time and place of capture, carapace length, width, height, mass, sex, and age. If it's a first-time turtle, he will give it an ID, notching its shell with a drill and file. If it's a recapture, he wants the ID recorded along with any changes in size and condition. Everything goes into the computer, into the database.
As Roosenburg holds her, the turtle keeps twisting in his hands, oblivious to his lecture on field data, her claws paddling the air as she tries to crawl back to her home river. She's clearly a survivor, with the scars to show for it. "This is from spending a lot of time in pound nets," he says pointing to scrape marks along her legs. That goes into the computer also.
One fact comes out of the computer immediately: this 40-something female has shown up in Roosenburg's nets 14 times in 20 years. Recapture rates like this are good news for the naturalist because every time this turtle reappears in his nets, she adds a new data point, making his demographic records even more robust. To date he has more than 30,000 captures of more than 10,000 terrapins.
Other facts come out: this lady terrapin seems to have lived her entire life within three miles of here. Four decades ago her mother dug a small hole, probably in sandy soil along a local creek, perhaps urinating to soften the ground. There she laid her eggs, a baker's dozen in most cases. Life in a turtle nest is either quiet or catastrophic — with catastrophes coming in the form of foxes or raccoons, both adept at sniffing out turtle urine and digging through the sand to feast on turtle eggs. The hatchling that grew into this hefty female first came crawling out of a lucky nest as a tiny turtle, pea green and perfectly formed — but still easy prey. Like most females, she outgrew every male in the river, but did not reach sexual maturity until age eight or later. Thanks to her size she survived foxes and raccoons; thanks to luck, she survived watermen's nets and motorboats, two of the leading killers for large terrapins.
Every November or December, she hibernated, swimming to the bottom of a small, deep creek and digging herself into the mud for a long winter's sleep. Scientists call this
Shipping his oars, he leaned over and suddenly saw turtles gliding under and around his boat, turtles by the dozens. He was floating through a herd of hundreds.
brumation rather than hibernation, but by any term it's a neat trick for an air breather who normally likes to sun herself on rocks and tidal flats.
Once past puberty she began mating with male terrapins, and several times a year she dug her own nest and laid her own clutch of a dozen or more eggs. Each year, however, she found fewer nesting beaches as new homes replaced old farms and new owners put in more riprap and bulkheads and docks along their waterfronts. How many offspring from this 40-year-old are likely to survive? According to Roosenburg's numbers, perhaps one in a hundred.
Pausing in his lecture, the naturalist looks the terrapin dead in the eye and smiles. It's not clear whether the biologist is catching the turtle or she's catching him. "Hey babe, how you doin'?" he asks, one survivor to another. "Welcome back."
Like his lady terrapin, Willem Roosenburg grew up on this same river. The biologist is the son of a biologist who also worked the Patuxent. Bill Roosenburg was a field worker at a small field station that the Chesapeake Biological Laboratory established at Hallowing Point. On a nearby bluff above a farm, Bill Roosenburg built a home with a view of the river where young Willem spent much of his free time. He hung around with biologists and grad students at the station, hitchhiked rides on the research boats, and learned to pull sampling nets. Like the sons of local watermen, he also learned to fish and boat and trotline for blue crabs. Rowing on the river one day, he spied small, dark bobbleheads popping up, then disappearing. Shipping his oars, he leaned over and suddenly saw turtles gliding under and around his boat, turtles by the dozens. He was floating through a herd of hundreds. An accidental vision that proved prophetic.
After high school he left to become a biologist, starting the long, slow swim towards a Ph.D. When he was finally a doctoral candidate at the University of Pennsylvania, he went looking for a dissertation topic and a site for his field research. He thought again about the Patuxent. His father was there and now he was struggling with health problems. And all those turtles were there.
He began with a proper Ph.D. question: did ground temperature in the nest determine the sex of the hatchlings that emerged? It was an odd phenomenon, one found in other turtle species, but not documented in terrapins. In most animals, of course, sex is determined when an egg is fertilized, not when it sits buried in a nest much later. It was a question he would study in the field and later in the lab, working with biologist Al Place at the Center for Marine Biotechnology of the University of Maryland Biotechnology Institute in Baltimore.
During his first summer in the field, he worked completely alone, setting out fyke nets, catching and marking terrapins, tracking down nest sites, and checking the sex of little pea-green hatchlings as they came crawling out. It was a ragtag operation, but it was a start. When he came back for a second season, he was surprised by how many recaptures he was finding in his nets. That revelation opened the door to other research options, demographic studies exploring how local history and ecology create variations in life history traits. By the end of his third summer he was hooked. He realized he could do this the rest of his life.
After graduate school his life fell into a familiar rhythm. Fall, winter, and spring, he hibernated at Ohio University digging out his own niche in an academic habitat. He taught classes in ecology and evolution, supervised graduate students, and published well. Every summer, he packed up the family for the annual migration back to his home river. At the beginning of every summer the same question from the kids: why do we have to spend every summer in Maryland?
"To be quite frank with you, I love doing field work," Roosenburg admits. He's working his way through his sandwich at a picnic table next to his summer house. Lunchtime at his turtle camp is a do-it-yourself affair where he stocks the kitchen with bread and cold cuts and everyone makes his own. For the crew it's break time between finishing the lab work and hauling the turtles back out to the river where they'll be released to go look for their own lunch.
Field work like this has its joys — and its sorrows, the kind of emotional complexities rarely found in lab-based experiments or computer-based ecosystem modeling. For many in the natural history tradition, the joys can be seen in their writings, whether it's Thoreau poking around Walden Pond, Darwin picking up plants in Patagonia, or Aldo Leopold tending his Sand County farm in Wisconsin. The same joys can be heard in Roosenburg's lunchtime talk about tracking terrapins along the Patuxent. "I love being outside," he says. "That's the most important reason why I am a biologist." But the sorrows are there also. Field work in the 21st century has a flip side: a working naturalist often comes face to face with the decline of the animals he's studying.
The best summers for Roosenburg — as a scientist and a Southern Marylander — were the seasons he spent working together with local watermen, catching fish in bank traps under his own commercial license and catching turtles for his research project. Bank traps are tall boxlike cages that watermen use for catching gizzard shad, catfish, yellow perch, and peeler crabs. These large wire cages sit out from a river bank, sticking up out of the water at the end of a long stretch of net that runs directly out from the shore. When fish and crabs and muskrats and turtles are cruising the shallows, they encounter the net and try to swim around it. Their detour lands them smack in the bank trap.
For a turtle, a bank trap is usually not the worst fate. A proper trap stands tall enough that its top sticks up out of the water, even at mean high tide, and air-breathing animals like turtles can rise up, stick their periscope-like heads above the water, and breathe. If the trap is not tall enough, however, or if the waters rise too high on a wind-driven tide, or if watermen don't check the trap regularly — then turtles and muskrats and others can easily die. Working with a local waterman, Roosenburg would pick live turtles out of the traps, haul them off to his field lab to record data, then return them lovingly to the water.
For the terrapin biologist, the bank traps were a bonanza. The income from his commercial catch bought fuel for the boat and paid room and board for his field assistants, and the turtle catches added data to his growing demographic study of the species. On good days he was taking more than 100 turtles out of 35 bank traps. On his best day he hauled home 196 turtles, nearly all of them large females. Turtle bags completely filled the back of his pickup truck, and two teams of assistants had to spend eight hours recording, measuring, and marking before heading back out in boats in the middle of a northeaster to get the turtles back in their home waters. Hard work every day, but for a Southern Maryland boy, it was the best of two worlds: he could be a waterman and a scientist at the same time.
One of those worlds came to an end with the great bank trap war of St. Mary's County. It was a war between watermen and landowners. As waterfront farms along the Patuxent gave way to new homes with large, well-mowed riverfront lawns, many of the arrivistes from the cities and suburbs began complaining. These odd-looking bank traps with their stakes and nets were spoiling the view from the lawn. While some watermen were willing to move their traps away — some were not, citing fishing rights that date back hundreds of years. It was the kind of culture clash, full of ironies, that has become familiar in the tidewater regions of Maryland.
Caught in the cultural crossfire were the scientist and the terrapin. As the battle heated up, moving from local disputes towards legislative action, Roosenburg lobbied to keep the bank trap tradition alive, partly out of friendship with watermen, partly out of self-interest in his large turtle hauls, partly out of fears for what would follow. He even ran a large study of bank traps for the Maryland Department of Natural Resources (DNR) that identified ways to make them even more turtle safe.
When watermen lost the bank trap battle, Roosenburg's worst fears soon came true. After the legislature banned bank traps in St. Mary's County in 2001, watermen turned to fyke nets as they warned they would, and turtles began dying in larger numbers as the scientist warned. Fyke nets don't stick up above the water unless a float is inserted to create space for air breathers. Roosenburg would keep floats in his nets, watermen would not.
The scientist lost his large turtle hauls as well as some long-standing friendships with watermen. When DNR officials caught watermen illegally keeping blue crabs caught in their fyke nets, the agency also closed down their commercial fyke nets. That left the biologist as the only legal fyke netter, a fact that enraged some local watermen who immediately blamed Roosenburg, sometimes confronting him on his collecting trips. "They swear that I was the one that turned them in," he says. "Somebody else called them in and I took all the heat for it."
The summer of 2001 was the low point. The crisis dissolved his friendships, a loss he regrets. "I'm from Maryland, I admired the waterman's way of life," he says. "That was friendship that I cherished." Bank traps were gone, watermen were angry, an oil spill was killing turtles, populations were dropping, his father was dying. "That all happened in one bang," he says. "Those were the dark days of my life."
Maybe you can go home again, but you can't step twice in the same river. On Roosenburg's river, farms were giving way to new houses, nest sites were disappearing, winter oystering was hitting new lows, and more watermen were turning to turtle catching. By 2001 terrapins were also facing dark days.
Roosenburg, however, was already quietly at work in another kind of war, a gathering campaign to save the estuary's oldest inhabitant. One of his projects highlighted the huge threat from recreational crab potting, an old-time tidewater tradition. It documented turtle deaths by drowning in all those crab pots hanging off all those community and private docks. According to Roosenburg, these accidental kills probably wiped out turtle populations decades ago in many rivers. Another project designed and tested bycatch reduction devices, now required by law, that can keep turtles out of these lethal pots. Yet other projects explored ways to make bank traps safer and tested fences for keeping predators off nest sites.
Findings like these came out of natural history work that went beyond classic observational surveys to include field experiments, hypothesis testing, and mathematical modeling of populations. This kind of natural history work could clearly have payoffs for conservation — at least if its findings are applied.
One of his key findings was applied when Maryland terrapins suddenly faced a new threat. The trouble began not in the Chesapeake but in China, a country that began importing more turtles in the 1990s for consumers who had long valued turtles for their meat and their alleged powers for fighting cancer, enhancing virility, and extending longevity. The fast-growing China trade began decimating turtle populations in Myanmar, Vietnam, Borneo, Java, and Sumatra. Conservationists called it the "Asian turtle crisis," and began warning that an American turtle crisis could be next.
In Maryland local groups began lobbying the legislature to close down the commercial fishery for diamondback terrapins. They pointed to incomplete harvest records that showed a fishery that was still small — but ready to explode. For 2002 DNR estimated a harvest of only 151 terrapins. Four years later, however, with only 14 watermen working the fishery, the harvest jumped to 11,010 terrapin taken. The China trade could now quickly draw dozens or hundreds of watermen into the terrapin fishery and set off a turtle fishing boom that could prove disastrous.
The new lobbying campaign lasted several years with Roosenburg playing an advisory role — low-key, but persistent. As a member of the Chesapeake Terrapin Alliance, he was one of several scientists arguing that terrapins — because they are late-maturing, low fecundity animals — are easy to overfish. "He was quietly advising us that this was not a species that needs a fishery in the face of a declining spawning habitat," says Harley Speir, a fishery manager for DNR, the agency caught in the middle between conservationists, watermen, and legislators. In 2006, the campaign won a partial ban based on turtle size — and the harvest actually jumped. The next legislature enacted a complete ban on the commercial harvest of the diamondback terrapin. A new governor, Martin O'Malley, quickly signed it into law.
Some of the clinching evidence came from Roosenburg's work. Called to testify before legislators the biologist spelled out a take-home message from the only long-term study of terrapins in the Bay. In the last 10 years, terrapin populations had already declined 75 percent in his home river, said Roosenburg, with hardly any commercial harvest in the region. A boom in the harvest could quickly drive the species down for decades.
Local research carries weight because it is local, suggests Speir. "It was significant," he says of Roosenburg's research. "It was the only real data we had for this area."
Poplar Island Success
AN ISLAND THAT nearly vanished is making a comeback. The U.S. Army Corps of Engineers built dikes and used dredge material to rebuild Poplar Island. Now the wetland cells on the island are home to thousands of terrapins. [more]
Willem Roosenburg kneels down next to a canal-like creek and pulls three little green hatchlings out of a bag. He sets them gently on a small, stony beach bordered by thick, high-standing marsh grasses. The hatchlings stand motionless for a good 30 seconds, then one clambers over a stone, slips into the water and begins waving its legs like it wants to swim. The other two look around, then clump off towards the marsh grass.
The biologist snatches them up and plunks them back at water's edge where they glance around again, then finally take the first plunge. "Okay guys, have fun," says Roosenburg. "See you in a few years."
It's his last field day for the summer, and he's spending it on the eastern side of the Bay on Poplar Island, the site of his second field research study. Once stretching over 1,000 acres, Poplar Island broke apart with time and erosion and land subsidence, dwindling to three smaller islands totaling less then 10 acres. Since 1998, the Army Corps of Engineers has been diking and filling to construct a large artificial island and dumping ground for all the dredge material that is dug out of the shipping channels of Chesapeake Bay every year. One key question for the Corps: can this new/old island also become a habitat for birds and, perhaps, for terrapins? That's why Roosenburg is here.
Some Natural History Classics
"It is a commonplace of all religious thought, even the most primitive, that the man seeking visions and insight must go apart from his fellows and live for a time in the wilderness. If he is of the proper sort, he will return with a message." So wrote Loren Eiseley, the scientist who made himself a great American writer. For several centuries natural history writers of the proper sort have ventured into America's natural world and returned with messages that helped shape the country's science and literature as well as its conservation and environmental movements.
Henry David Thoreau,
Walden. By the writer who made himself a natural historian.
George Perkins Marsh,
Man and Nature. An early effort at ecological thinking that helped launch the modern conservation movement.
John Wesley Powell and Wallace Stegner (editor),
The Arid Lands. A report on the land beyond the hundredth meridian by the geologist who made several famous explorations of the Colorado River.
John Steinbeck (with Ed Ricketts),
The Log from the Sea of Cortez. The tale of a trip to collect flora and fauna of the intertidal zone of the Baja, by a famous novelist and his best friend, the marine biologist who became the central character in several novels.
Sand County Almanac. Its chapter on "The Land Ethic" profoundly influenced the literature of environmental ethics.
The Immense Journey. Natural history that takes the long view, and does so lyrically.
Silent Spring. The book that helped outlaw DDT and inspired the modern American environmental movement.
John and Mildred Teal,
The Life and Death of a Salt Marsh. The ecology of the salt marshes that edge the East Coast from Newfoundland to Florida.
Beautiful Swimmers. A natural history of blue crabs and the watermen who chase them.
Return to Warden's Grove. A new classic by a scientist who traveled to the Northwest Territories to study the Harris sparrow and learn about himself.
More on the Terrapin
Chesapeake Terrapin Alliance
Terrapin Institute and
To keep track of terrapin births on the site, the biologist has two assistants work the island every day. Ryan Trimbath and Tony Frisbee, both blond and slightly sunburned, patrol the island's new wetlands, looking for nests, capturing and tagging and releasing hatchlings. Everything — the number and location of nests and hatchlings — goes into notebooks and then into the computer.
Answers are already coming out of the database they've built, answers that bode well for Roosenburg's hopes for a terrapin restoration. Back in the Patuxent, he was finding survival rates running about one hatchling per hundred. Here on Poplar, he's getting survival rates of 70 to 80 percent. No commercial harvesting for the China trade, no foxes and raccoons, no riprap and bulkheads blocking off the beach, no crab pots and bank traps and fyke nets to drown in. The only predators so far seem to be birds. If these survival rates keep up, the Corps could rename the place Turtle Island.
After his dark years on the Patuxent, the Poplar Island experience has been hope-inducing for Roosenburg. When the Corps first approached him about monitoring terrapins on a manmade island of 1342 acres, he had his reservations. "Now that I've looked and seen those wetland cells," he says, "you'd be pretty hard pressed to tell the difference between them and other wetlands here on the Eastern Shore." Poplar will double in size over the next decade, and restored islands like this could indeed swell Baywide terrapin populations.
What does Poplar Island mean for the mainland? The experience here stands as a rough "proof of concept" for some key steps that could be tried elsewhere. The ban on commercial harvesting will help, says Roosenburg, but more is needed. Watermen could check their bank traps and pound nets and fyke nets regularly (as many already do), recreational crabbers could fit their pots with bycatch reduction devices (as they are now legally required to do), landowners could begin replacing riprap and bulkheads with "living shorelines" that are graded and vegetated (as some are doing already). These may look like baby steps, but they are a start.
They could slowly bring more terrapins back to the mainland rivers where they were always part of the life and spirit and sense of place in tidewater Chesapeake, a world where a boy in a boat could look down and see hundreds of terrapins passing by.
Reaching into a long, tan bag, Roosenburg grabs another handful of little hatchlings and holds them up for picture-taking. This morning's launch is being staged for two writers, two photographers, and a videographer. The new harvest ban seems to have stimulated more press interest, both in the diamondback terrapin and in the biologist who's built a career trying to save them.
Roosenburg has only 15 hatchlings to release this morning, but it goes slowly with frequent retakes and multiple camera angles. Each baby terrapin gets a well-photographed bon voyage. "When we have 150 of these to release," the biologist chuckles, "there's a lot less ceremony."
Finally he pulls the last terrapin from the bag, the last release for Roosenburg's summer before he migrates back to academe. Atop a small grey stone, the lone diamondback stands its ground, tiny and charismatic and eerily confident, the newest apparition of the oldest animal life in the estuary.
"He doesn't want to go," says Roosenburg. "He likes it here too much."