Vanishing Vernal Pools: A Wetlands Conservation Decade
Vol. 13 Issue 1, Spring 2008
By Mike Hayslett
A Non-Unique Problem
The colossal loss of historic wetlands in our country has come to light significantly in recent decades. The US EPA’s web site summarizes the phenomenon this way:
In the 1600s, over 220 million acres of wetlands are thought to have existed in the lower 48 states.
Since then, extensive losses have occurred, and over half of our original wetlands have been drained and converted to other uses.
The years from the mid-1950s to the mid-1970s were a time of major wetland loss, but since then the rate of loss has declined.
As we celebrate the 400th anniversary of the Old Dominion, we somberly recognize that this trend began here at home, and our own state has half the wetlands it once did. The destruction of these valuable habitats has been especially striking in Northern Virginia and Loudoun County, where an abundance of wetlands faces a rate of suburban growth that ranks highest in the nation!
To add insult to injury, isolated wetlands currently lack federal protection (though the Department of Environmental Quality does regulate them in Virginia). The complexity of various categorizations for freshwater wetlands and even disagreement by experts over what constitutes a “vernal pool” muddy the water further. These complications have created an unfortunate tangle of legal hierarchy for these disappearing treasures, and we can ill afford to loose another single acre these days. In light of this challenge, I find myself battling to save every pothole. In my own frustration, I’ve often contended for simplicity and inclusion with the retort, “If they’re WET lands, then they’re wetlands!”
But let’s look on the bright side. Northern Virginia is naturally blessed with LOTS of wet places, and though this may represent a headache for homebuilders and regulators, it has presented a veritable Xanadu to me for a decade! I’ve often said that three reasons keep me coming back to visit and help spread this message: 1) lots of wetlands, 2) lots of wetlands loss, and 3) lots of wetlands-loving friends!
Northern Virginia’s Unique Position
Why so many wetlands? Portions of Loudoun and several other northern Virginia counties fall within the largest band of Virginia’s Triassic Lowlands: the Culpepper Basin. This ancient swamp region is characterized by hydric (“drainage challenged”) soils which cause high densities of isolated surface wetlands. The only comparable area I’ve encountered in the state might be the Danville Basin in Pittsylvania County. Flooded fields viewed from your car in passing are likely Triassic wetlands, and these isolated wetlands often hold water for only a portion of the year, hence they are “vernal” or seasonal.
Loudoun is also within the Commonwealth’s “physiography squeeze.” This is a distinct area where the generally distant regions of the mountains and the coast come close together. The county therefore has both montane and lowland environments to support a variety of wetland types and their specialized wildlife (i.e., “indicator species”).
In fact, this proximity of Blue Ridge to Coastal Plain causes the ranges of at least two mountain amphibians to extend closer to the ocean than anywhere else in the Commonwealth. The Jefferson Salamander — a northern species of cooler and higher climates — occurs well into the Piedmont in Loudoun, where it reaches the easternmost limit of its range in Virginia.
Thanks also to the combination of relict swamp soils and geologic squeezing, the Wood Frog is likely more abundant in Loudoun than any other county in Virginia (Fairfax still has many left). I continue to be amazed at how commonly they occur here in Northern Virginia!
A Decade of Vernal Pool Promotion
These unique ecological circumstances have enticed me annually to Northern Virginia. It has been my great pleasure to work with the Loudoun Wildlife Conservancy, Audubon Naturalist Society, and other organizations over the past decade to seek out these habitat gems, pursue their preservation, and help raise public awareness of their value.
I have gained so many stories to tell, both sad and successful. We have been able to reach thousands of students at a dozen schools through assemblies, classroom visits, and field trips (and that’s but a fraction of the 68 schools with 53,000 students in Loudoun). An especially rewarding experience has been an annual four-day series with the Environmental Explorations students at Loudoun Valley High School. We’ve also reached adult audiences through lectures, workshops, and field forays at over 30 locations in parks, preserves, private lands, and public places.
Providing technical support for the Rust Pond acquisition and development of the new amphibian monitoring program (LAMP) are memorable highlights of this campaign. Evaluating and documenting hundreds of these wetlands around the region and consulting with owners/ managers about their importance as wildlife habitat has been a staple activity of each visit. Some examples of the many field finds warrant mention.
Unhappy Scenarios & Hopeful Successes
Following a Naturalist Center program at Leesburg in my early years, a Wood Frog specimen in a jar led me to nearby Sycolin Road, where a half-acre willow swamp site suffers from urban multi-stress symptoms. Cleared surrounding forest, no protective travel corridor for salamanders, reduced upland habitat, traffic danger from adjoining roads, airport expansion, and now stormwater features crowd this vernal pool’s natural space and threaten to whittle it and its resident wildlife away to nothing.
A participant approached me after a public presentation further to the east. She told me that a new library had been built on a flooded meadow where Spadefoot Toads once uttered their odd calls. Now the only known site left in the county for this rarely encountered amphibian is near Balls Bluff. Let’s hope it doesn’t become extirpated.
To the insidious threat of urban sprawl devouring these precious habitats, we now add the apparent effects of climate change. As rainfall cycles become less dependable, seasonal wetlands may not hold water long enough for their dependent creatures to complete their life cycles, and phenological mayhem ensues as amphibians respond to false weather cues, migrating outside of their traditional seasons. It is easy to get discouraged with all these troubles, but there are reasons to rejoice and some encouraging battles have been won.
Dedicated in 2003, the Rust Pond is an unusual bog-like wetland isolated atop the Catoctin ridge where it holds water permanently, even in severe drought. Though it is not an ephemeral or “vernal” pool, this unique wetland hosts Wood Frogs, rare albino Green Frogs, and the most easterly occurring Jefferson Salamander population in the county. Five acres of this unique site were purchased for some $450,000 through grassroots efforts, and the pond is now part of the ANS Rust Sanctuary in Leesburg.
In 2004, Loudoun Valley students helped discover the first documented Loudoun County Marbled Salamander population at the Blue Ridge Center for Environmental Stewardship near Neersville. This preserve has an impressive assortment of wetland types and harbors at least four of the six vernal pool indicator wildlife species (also called “obligates”) found in the county.
Not in nine years of mucking through Northern Virginia’s soggy spots had I confirmed one viable population of Fairy Shrimp (the freshwater crustacean that is also a vernal pool obligate), until last spring when we made an exciting and anxious discovery in the Lucketts area of Loudoun. Our team found a fantastic natural complex of woodland wetlands near Stumptown.
These ponds are some of the most pristine examples of forested wetlands that I have seen in the region, and they are especially unique in being karst sinkholes. This part of the county, located along the eastern base of Catoctin Mountain, is underlain by limestone (consider the local name “Lime Kiln Road”), making Loudoun the only Piedmont county in Virginia with karst topography.
That makes these vernal pools especially unique in Loudoun, as they appear more akin to environs of the southern Shenandoah Valley than the Potomac River region. Five vernal pool obligates have been found among seven pools so far — the highest diversity of these indicator species we’ve seen at any one location in Loudoun.
These facts make this site my 2008 “poster pool” for the wetlands conservation message! Especially since the future of this area is precarious, with housing development encroaching upon what’s left of these ancient vernal pools.
Now with LAMP volunteers and many other folks versed in the importance of these marginalized wetlands, vernal pools and their denizens are being found, defended, and given a voice. Let us strive to see that special places like the Stumptown Sinkholes — which may have persisted for millennia before us — can be preserved for the future.
I am very grateful to all of my wetlands-loving friends in Loudoun County and Northern Virginia who have contributed to the realization of this benchmark year. Thanks for helping to champion these vanishing vernal pools!
Now that you’ve read this article, try our Vernal Pool Word Search Puzzle!