Watershed Moment: The Past, Present and Future of Big Darby Creek
There’s more to freshwater mussels than meets the eye, mostly because you can’t readily see them. They lurk under the substrate of a river, in the dark places between rocks and pebbles. You can go and stand at the edge of the cool, lapping water and you might see some fish here and there, maybe a crawdad sticking halfway out from under a rock. Maybe you’ll see some remnant shells of creatures long dead, but they’ll give you no indication of the complex, dramatic and fragile life of an American freshwater mussel.
“The first thing to know,” John Tetzloff told me, “is that they don’t have sex in any way that we would recognize.”
Tetzloff has been the president of the Darby Creek Association for 20 years. He is the manager of the Hilltop Branch of the Columbus Metropolitan Library, and he is a mussel person. Mussel people are a little bit like birders, except their quarry is not so ostentatious as to flaunt vibrant feathers and sing attractive songs.
“I like their obscurity and rarity,” said Tetzloff. “It’s a challenge to find them. There’re not many people in the world that can find a mussel.”
Tetzloff took me on a brief tour through the convoluted mussel reproduction process. Though they eschew intercourse, there are still female and male mussels. The males release sperm into a stream and the females encounter that sperm, fertilizing and developing something called glochidia, which are sort of like almost-microscopic baby mussels. But if the glochidia want to get anywhere they have to latch onto a fish.
To accomplish this, some mussels will develop lures shaped like smaller fish that bigger fish want to swallow. The lures then explode, releasing glochidia into the fish’s mouth and gills. Other mussels attract fish with their bright inner bodies. When a fish comes close enough, the mussel snaps its shell down on the fish and pumps it full of glochidia.
Tetzloff assured me none of these methods seem to be fatal to the fish, but still, who knew a mollusk could be so violent?
Mussels can live for decades, but they more or less stay in one place. That means that whatever happens to a stream — a drought, a flood, a sewer spill, an algae bloom — happens first and foremost to the mussels. The different species of mussels have delightful names like the kidneyshell, the rabbitsfoot, the purple wartyback, the Northern riffleshell, the mucket, the fat mucket, the plain pocketbook, and so many others. Mussels are filter feeders, naturally cleaning the water in which they live.
“They’re a fundamental part of a normal North American stream,” said Tetzloff. “Now, there aren’t a lot of North American streams that still have mussels. A lot of the streams in central Ohio that people are familiar with — Alum Creek, Big Walnut, Scioto — have very few mussels left and just a few species. This is a relic of what used to be here.”
The “relic” Tetzloff refers to is the Big Darby Creek. The Darby is 84 miles long, with a 550 square mile watershed stretching into Logan, Union, Champaign, Madison, Franklin and Pickaway counties. Beneath its ripples and riffles live at least 43 different species of freshwater mussel — more than all of Europe. It’s home to four federally endangered mussel species and several others that are otherwise rare or threatened. The Darby is recognized as both a State Scenic River and a National Scenic River, and its cool groundwater and limited human interference have made it a refuge for animals that couldn’t survive in the state’s other polluted waterways.
The Darby is a miracle of biodiversity and a success story in the modern environmental movement. But it’s also a fragile ecosystem situated in the middle of a fast-growing metropolis. Columbus and its suburbs are advancing on the Darby watershed, the remarkable conservation agreement that protects it is now strained, and it’s just been declared one of the most endangered rivers in America.
And one more thing — some of the mussels are disappearing, and no one quite knows why.
A Burning Library
When John Watts came up to Columbus from rural southern Ohio, Otterbein University was still Otterbein College. Watts was there to become a veterinarian before botany classes turned him toward a different career. Today he’s the resource manager for Columbus and Franklin County Metro Parks, where he’s worked for more than 30 years. His responsibilities include the 9,000 acres of the Big Darby watershed owned by the parks district.*
“One of the unique things about Big Darby Creek as a federal scenic river is that it’s located kind of in the middle of this 2 million people metropolitan area,” Watts told me. “And when you’re out on the creek, when you’re out in the middle of it, it doesn’t feel like you’re in Franklin County. You’re 30 minutes from High Street and Broad Street, but there’s no sign of man. You might get a plane go over.”
“How many federal scenic rivers do you have with that kind of accessibility?” said Watts.
Big Darby’s ecological success in a time of ecological degradation is due mostly to good luck. The geology, Watts told me, seems to work in its favor. Underlying limestone maintains the water quality and seeping groundwater makes the creek a cool, welcoming habitat for freshwater mussels and fish. Native Americans and European settlers once used the creek for limited purposes, fishing out mussels for food and decorative pearls. But other than agriculture, there was never much industry on the Darby of the sort that ruined other Rust Belt rivers.
Lots of Ohio streams were probably like Darby once, Watts told me. There are historical records of rare fish in Blacklick Creek, Alum Creek, and Little Rocky Fork. However, “those things were closer to Columbus,” said Watts. “They developed first.”
Not only has the Darby proved to be survivor, it’s also served as a refuge for species that could not survive elsewhere. According to Anthony Sasson of the Midwest Biodiversity Institute, Big Darby helped save some of the freshwater species that had once just about disappeared from the Scioto River.
“The Scioto was so polluted that it wiped out all those species below Columbus,” said Sasson. The only safe place was Darby.
“Darby is very well suited and has been very lucky,” Tetzloff told me. “It dodged a bullet that a lot of other streams haven’t dodged.”
That’s not to say plenty of bullets haven’t been fired.
“It was back in the… late 60s early 70s, when there was a dam proposed,” said Tetzloff. “And this was it.”
He gestured out at the bison pastures beyond the balcony of the Battelle Darby Metro Park Nature Center where both of us sat.
“This would’ve all been underwater,” he said. “The Army Corps of Engineers planned to do a flood control dam here and that got a lot of the locals upset.”
Then there was the other dam on the Darby, proposed by the City of Columbus to create a drinking water reservoir on the land that is now Prairie Oaks Metro Park. It was this proposal, at the dawn of the environmental movement, which would spark a decade-spanning political and legal battle.
“It also came to the attention of environmentalists from Ohio State who were aware of the special significance of the biology,” said Tetzloff. “Columbus was lucky that we had a couple of mussel experts here who knew what it was. So it was that teamwork between local political pressure and scientific arguments that carried the day eventually.”
Those mussel experts were Dr. David Stansbery and Dr. Carol B. Stein, both of OSU’s Museum of Biological Diversity. Stansbery built the Museum’s extensive mollusk collection, which today is the second largest such collection in North America.
Dr. Stein passed in 2010. Dr. Stansbery passed in 2017.
“You can’t say enough good things about Dr. Stansbery,” said Dr. G. Thomas Watters, Curator of Mollusks at the Museum of Biological Diversity. “I was his last graduate student, whether he wanted that or not.”
According to Watters, Stansbery and Stein were among the first scientists to take their environmental concerns into the public sphere. Stansbery advocated for freshwater mussels and aquatic systems in Ohio, Alabama and Mississippi, at one point even testifying before Congress.
“He went out there way before it was fashionable to do so to try and stop dams and impoundments and that type of stuff,” said Watters. “Way ahead of his time in terms of a conservationist spokesperson for these animals. Up until then people just thought they were living rocks, basically.”
“Carol Stein, she’s my hero,” said Tetzloff. “She was dogged. She wrote a lot of letters, she wrote very good letters.”
Dr. Stein built the Museum’s collection of gastropods — snails, that is. She had been working in the Darby and studying its unique ecology since the early 1960s. She knew the dam would obliterate dozens of species that depended on a safe, stable environment to survive. The Darby, Stein wrote to the Dispatch in 1974, “is a priceless and irreplaceable remnant of wilderness and the people of Columbus will lose forever the opportunity to enjoy this natural heritage if they allow it to be dammed.”
In another letter, Stein compared damming the Darby to “burning a library of rare books as fuel to cook a meal.”
At that time it was burning rivers, rather than libraries, that captured the nation’s nervous attention. In 1969, the perennially polluted Cuyahoga River caught fire and the disturbing image of burning water finally shook America out of the notion that all was well with the environment. The far more troubling fact was that this was not the first time the Cuyahoga caught fire, nor even the second. It was something like the thirteenth.
In modern retellings, the Cuyahoga fire had a cascading effect on the national environmental movement. From out of that burning river came the Clean Water Act, the Environmental Protection Agency, the Endangered Species Act, regulations of pesticides, recycling, Earth Day, “Big Yellow Taxi,” the Blue Marble photo from Apollo 17, how small we all are, a mote of dust suspended in a sunbeam, yada yada, you know the rest.
While that wave of environmental concern swept the nation, central Ohio fought its own battle of the movement on the banks of the Darby. Scientists like Stein and Stansbery spread the gospel of Darby’s biodiversity and local governments chafed at the big city’s obnoxious encroachment, and the situation came to a head in the form of a good old-fashioned constitutional question.
At some point in the dam fight, the state stepped in to block construction under Ohio’s scenic river law — a law the City of Columbus then argued was unconstitutional. On March 29, 1978, the justices of the Supreme Court of Ohio unanimously sided with the state, declaring that Ohio indeed had the right to protect its most precious rivers and streams.
“Enlightening in this regard are the debates of the Constitutional Convention of 1912,” wrote Justice Thomas M. Herbert. “The thinking revealed therein is strikingly relevant to the widespread environmental and ecological concerns of the 1970’s.”
Justice Herbert then quoted a “Mr. Miller” of Fairfield County, who said in 1912, “We have no right to waste our natural resources and thereby deprive the people of the future of that which belongs to them.”
In 1984, eight years after that Ohio Supreme Court decision, Big and Little Darby Creeks were declared state scenic rivers. Ten years after that they became national scenic rivers. And just this month, in the same document that declared the once fire-prone Cuyahoga “River of the Year,” the environmental advocacy organization American Rivers listed Big Darby Creek as one of their most endangered rivers of 2019.
So, you might say things have changed.
The Darby Wars
In June of 2004, the Ohio EPA published a report with the ominous title “Darby at the Crossroads,” based in part on a systematic survey of the Darby watershed conducted between 2001 and 2002. The report found that while much of the watershed remained healthy, a number of the tributaries and parts of the Big and Little Darby creeks were showing signs of degradation.
“Among the most visible and widely publicized future threats to the Darby is conversion of farm land to suburban and commercial land uses, especially in Franklin County,” said the EPA.
Also in 2004, Big Darby Creek was named one of the country’s ten most endangered rivers by American Rivers. Echoing the EPA, American Rivers identified encroaching development and urban sprawl as the primary threats to the watershed’s integrity.
By the early 2000s, the Darby Creek Association, which had been working on the creek’s behalf since 1972, was mostly doing public engagement activities like river cleanups and canoe floats. But with a renewed concern for Darby’s future coming from so many different sources, Tetzloff and the Association decided it was time to take on a public advocacy role, and identified development from Columbus as the Darby’s number one threat.
“There was a period of rancor that was several years of fights,” said Tetzloff. “A lot of us like to refer to it as the Darby Wars.”
Tetzloff and the Darby Creek Association attempted to stop development in the watershed by way of a ballot initiative. To get the initiative on the ballot, the Association set out to collect thousands of signatures from voters who wanted to protect the Darby.
“I remember they would be at the ComFest collecting signatures and people would actually go up to them and ask to sign rather than people like John asking them first,” said Sasson. “It was that much of a high profile event.”
The first round of petitioning turned out to be a dud.
“We turned them in and they were all thrown out on a technicality,” said Tetzloff. “Our lawyer made a serious mistake”
So they turned around and did it again. With enough signatures collected and the petition legally sound, Columbus Mayor Michael Coleman and City Council President Matt Habash ultimately agreed to a moratorium on extending sewer service into the watershed without the ballot measure going to the voters. But the Association knew the moratorium couldn’t last forever, and when it was lifted the Darby watershed would need a comprehensive, multi-jurisdictional land use plan in order to survive.
“So in other words, there had to be an agreement that everybody agreed to,” said Tetzloff. “Which was critical because all these townships out here… they didn’t trust Columbus at all. They hated Columbus. They thought that Columbus’ goal was to pave them over and annex them out of existence. Which it probably was.”
According to Tetzloff, the EPA stepped in to help organize discussions between the county, the city and the townships. From that back and forth between the communities of Franklin County came the Big Darby Accord.
Signed into existence on June 30, 2006, the Big Darby Accord requires that if a proposed development in the watershed is a certain size and meets certain criteria, the proposal must go before an advisory panel appointed by the county, the townships and Columbus. Tetzloff is a member of the advisory panel representing Columbus while Sasson is a member representing Franklin County. The panel’s job is to review proposed development projects and give local governments in the watershed non-binding opinions on whether a proposal conforms to the Accord, but it’s still up to local governments to approve or reject those proposals.
Ultimately, the enemy in all of this is runoff. When rain falls on natural ground, the water is filtered through layers of soil, which cleans it of pollutants before it reaches the stream. A stream that takes in groundwater is cooler and gentler, and serves as a perfect natural habitat. But when rain falls on impervious surfaces like roads or driveways, it goes straight to the stream with all the pollutants it can collect on the way.
“It could be fertilizer on a lawn, it could be gas or oil from cars, salt in the winter, that’s all getting into the creek,” said Tetzloff.
The Accord, Tetzloff told me, is a big environmental equation. As the undeveloped areas and farmlands that once surrounded Darby are transformed into suburban human habitats, soil is replaced by impervious surfaces and runoff becomes more dangerous to the creek. For this reason, the Accord also recommends that signatories purchase open space in the watershed to offset the land being developed. This part of the equation has not panned out.
“That’s totally stalled, unfortunately,” said Tetzloff. “It’s basically languished for this entire time. 2008 was two years later.”
The Great Recession of 2008, while devastating to the human economy, had the positive environmental effect of making development in the Darby watershed temporarily unattractive. Tetzloff said there were some years when no development projects would come before the advisory panel at all.
“I don’t want to say ‘convenient,’ but serendipity I guess that those two things occurred together,” Sasson said of the Accord and the Recession. “That’s bought some time to figure things out.”
Now, with the economy recovered and developers returning, time is up.
The Last Collection
The Ohio State Museum of Biological Diversity on Kinnear Road looks like a proper university laboratory. Which is to say, it’s a maze of hallways with tantalizing and humorous suggestions of the science that might be taking place behind every closed door. One door warned, “Caution! Velociraptors spotted in this area. Take appropriate precautions.”
The Curator of Mollusks himself, Dr. G. Thomas Watters, took me to the mollusk collection built by Dr. David Stansbery decades ago. The collection, it turns out, is a warehouse-sized room with a series of shelves and sliding drawers full of nothing but mollusks. Mollusk shells, mollusks preserved in jars. Mollusks on mollusks on mollusks. Remember the last scene in Raiders of the Lost Ark? Add mollusks.
Dr. Watters pulled out one drawer and then another, waving his hand over each.
“This one is extinct,” he said over a particularly full drawer. “At one point it was common enough that whoever collected it could collect all of these.”
Watters opened another drawer.
“This is really neat,” he said. “This is extinct.”
“These are extinct,” he said. “Tennessee River… Muscle Shoals… People don’t realize Muscle Shoals was named after this mussel.”
On the way out we passed a table with a series of small display cases. Watters pointed one out. It was a small, black case preserving about a dozen pistachio shells.
“That was Stansbery’s last collection,” said Watters. “He thought that was funny.”
Earlier in his office, Watters told me Ohio is probably one of the best places to be a freshwater mussel. The state puts a lot of money into studying and protecting mussels and has some of the strictest mussel regulations in the country. It is illegal in Ohio to collect, shuck or otherwise harass a freshwater mussel. A good thing too, because when I told a friend about this story he immediately asked whether he could eat a mussel.
“Mussels in general are the most imperiled animals in North America,” said Watters. Of the almost 300 species of North American mussel, 38 are extinct and up to 70 percent of the remainder are imperiled. Most of those, said Watters, will disappear without human intervention.
One such intervention started several years ago, when OSU, Metro Parks, the Ohio Department of Natural Resources and the Columbus Zoo and Aquarium coordinated the introduction of thousands of critically endangered Northern riffleshell mussels from Pennsylvania’s Alleghany River into Big Darby Creek, where the native riffleshell population is dwindling. Pennsylvania at the time was in the process of demolishing a rusted bridge over the Alleghany, where the riffleshell is unusually abundant.
“We asked Pennsylvania, can we get some of these?” said Watters. “You’ll obviously have more than you need and they’ve got to get out from under this bridge.”
Most of the mussels transported to Darby were affixed with a passive integrated transponder tag — a tiny tracking device. In the years since the reintroduction into Darby, tracking the mussels has revealed they are moving around in the stream. But the most important question, whether the Pennsylvania mussels are reproducing in Darby, has yet to be answered.
In the meantime, the mussels of Darby face unexpected threats. In October of 2016, Big Darby Creek experienced a massive and unexplained die-off of mussels from a variety of species, igniting the worries of everyone associated with the creek and its ecosystem.
“I’d been out of town,” said John Watts. “I got back in town and they said, we’ve had a pretty substantial mussel die-off. And the first question I said was, how many fish are dead? And they said, yeah that’s the funny thing, none. I said, well, OK so there’s no ground zero.”
No, in this die-off, there was no ground zero. Surveyors discovered dead mussels for more than 50 miles, from Union County to Pickaway.
“By the time we figured out that something was happening, it was probably too late to catch it,” said Watters. “Whatever had caused this die-off was on its way to New Orleans.”
Three years later, the cause of the 2016 die-off remains a frightening mystery. And it could happen again.
“Nothing’s gonna fix itself”
The Darby, once again, is endangered.
That’s the decision of American Rivers, the environmental advocacy group that put Big Darby Creek on its yearly list of the 10 most endangered rivers in 2004. Just as in 2004, encroaching development and urban sprawl has put Darby back on the list. The report from American Rivers published on April 16 celebrates the 2006 Big Darby Accord, but warns, “as the region continues to grow, developers are suddenly attempting to leapfrog this barrier and develop thousands of acres of farmland to the west that is unprotected by the provisions of the Accord.”
That leapfrogging is possible because the Accord only applies to Franklin County, and the Darby watershed rather rudely ignores county lines. Even the most comprehensive protections like the Darby Accord only go so far if pollutants seep into the stream from any of the other counties of the watershed.
“Most frustratingly, the bulk of that development has been proposed by Columbus itself, which is a key signatory to the Accord,” wrote American Rivers. “They have petitioned the Ohio Environmental Protection Agency to extend their sewer plan to an area centered around the village of Plain City that would add 11,000 housing units and open a development zone the size of two of Columbus’ largest suburbs combined.”
“I think it needed to make the list,” said Tetzloff of the most endangered designation. “But it’s disappointing that it warrants being on the list. I mean, 10 rivers in America. You know how many thousands of rivers there are? They’ve identified us as being under threat. So it needs to be out there. Nothing’s gonna fix itself.”
Both Tetzloff and Sasson are adamant that the Big Darby Accord must be revised and made more stringent. The watershed communities, said Tetzloff, need to start developing a plan to acquire and preserve open space along the creek to compensate for the development that comes with an expanding metropolitan area. A new accord would also need to utilize environmental science that wasn’t available in 2006. And above all, Columbus must take seriously its outsized role in the Darby’s health.
“None of this is a guarantee,” said Tetzloff. “This kind of a thing that I’m envisioning hasn’t been done anywhere. There’s no example of a very high quality stream surviving amidst urbanization to any great degree. So it would be an experiment to see if it could be done.”
Tetzloff is open to that type of experiment. The Darby Creek Association, he said, is not anti-development, but believes development in the watershed must be gradual and sensitive to environmental impacts. After all, it’s not like the Darby has only recently dealt with humans.
“The Darbys are not pristine,” asserted Sasson. “It’s a working landscape and it’s impacted by people. And it’s been a long, slow decline of some of these mussels and the die off of 2016 was a symptom of the decline. It was not the thing that’s gonna wipe out these rare species… It’s just a sign that something’s wrong.”
The mysterious loss of the rare mussels is far from just a mussel problem.
“I tell people freshwater mussels are not the charismatic megafauna. They’re not cuddly or majestic or cute,” said Watters. “People always ask, what good are they? And of course what they mean is, what good are they to me? And what we tell them, and it’s true and it seems to make them happy, is that they are the canaries in the coal mine.”
Because mussels depend on fish — sometimes specific species of fish — to reproduce, declines in mussel population could indicate problems with certain fish populations as well. And because they generally stay in one place for most of their lives, mussels can pinpoint polluted areas of a stream.
“If I go someplace and I find lots of mussels and lots of species, to me that says this a place you can take your family and fish and whatever,” said Watters. “But if I go to a place and there’s dead shells or no shells whatsoever, to me that’s just sending up a red flag saying something’s happened here.”
The red flags are certainly up, but the exact threat remains obscure.
“I think it would be really nice to figure out why are the rarer mussels becoming rarer. We’re seeing other species of mussels becoming more common, so why is that?” said Watts. “Is it the common mussels can adapt a little bit more so… they’re gonna do fine? So why?”
Watts also said that it’s not just runoff and pollutants the Darby has to worry about. There’s also the omnipresent specter that no intra nor inter-county accord can stop.
“You can call it global warming, climate change, I don’t think you can really deny that the climate is changed,” said Watts. “We’re seeing rainfall of 55, 65 inches… The last few Julys have been very wet. So you have this just constant up, then down, then up, then down. And some of the floods have been pretty tremendous.”
The unusually heavy rains, said Watts, can damage the substrate, the rocky habitat where the mussels spend most of their lives.
“We always have to remember that any species, whether they’re rare or they’re common, their whole life is based on structure, just like ours,” said Watts. “We live in houses and condos and apartments and that’s our structure… They need that, and when that gets disrupted, it’s like a tornado hitting us.”
But despite those dangers, Watts remains hopeful. Simply by looking at the progress of the conservation movement surrounding Darby, there is reason for optimism. We’re better than we were, said Watts. That matters.
“I’ve learned that you’re never done,” said Tetzloff. “Because there’s always new people who come and are the decision makers, so you’re constantly trying to win that argument. The thing that we have going for us is that support for Darby is widespread and deep.”
The mussels are not, as Watters put it, cute or cuddly. For the most part they’re passive, unattractive, and obscure. In the course of writing this story, the interview that was hardest to make time for was the Darby itself. On a Thursday afternoon, I went down to the edge of the cool, lapping water and looked, but didn’t see any living mussels. I saw plenty of shells of different shapes and sizes, but the animals themselves were hidden.
I have no right, of course, to ask them to show themselves. They were here first, Watters told me. An ancient creature that probably dates back to the Triassic Period. Dinosaurs that trampled through the prehistoric creeks of North America trampled on mussels almost exactly like the ones living in the Darby today.
“People say, well if we lose this one species, is it a big deal?” said Watters. “Probably not. But a hundred years ago, people would’ve loved to have eradicated bread mold, and then we wouldn’t have penicillin. So you don’t want to start playing God… We don’t know what role these animals play or what good they might be to people, if they have to be good to people at all… they’re just part of our natural heritage.”
Our natural heritage, yes, but also part of our environmental heritage. Some of the same people who led the vanguard of the national environmental movement put their efforts and expertise toward saving the Big Darby Creek. Perhaps it’s no coincidence that during the brief resurgence of environmental consciousness in the mid-2000s, the Big Darby Accord came to life. And now, with climate change bearing down on us all, it may be necessary for a disparate collection of governments, private entities and individuals to agree that neither an ecosystem, nor its biggest threats, recognize any border whatsoever.
On Earth so it is in Darby.
*Disclosure — the author’s wife is employed by Friends of the Metro Parks