Vernal Pools: 20 Years of Conservation in Loudoun
Volume 23 Issue 1, Spring 2018
by Sharon Plummer
Vernal Pools are ephemeral wetlands that dot our landscape in Loudoun County and support an immense amount of wildlife. That is why for the last 20 years Loudoun Wildlife Conservancy has been trying to increase awareness of these important resources and to help preserve and protect them.
Loudoun County is endowed with so many types of riches in its lands and people that tug-of-wars over preservation priorities have been inevitable. As the population has blossomed, we have had to go to great lengths to make the voice of wildlife heard amid the honking horns. The official Loudoun Wildlife vision is — A place where people and wildlife thrive together. Our mission — We inspire, motivate and engage people to protect, preserve and restore wildlife habitat. So once vernal pools were discovered here and their ecological significance became clear, we knew we would need to raise our voice to higher decibels, and save as many as we could.
Loudoun is home to a rare type of karst terrain that is conducive to creating vernal pools. In this terrain, underlying limestone and similar rocks dissolved, leaving underground cavities, springs and shallow depressions. These depressions dry out for part of the year, so typically fish do not live in them, but they do provide fantastic places for amphibians to meet and breed. If you drew a half-mile circle around a vernal pool, the biomass levels would be much higher than in many other parts of the landscape because of the rich network oasis they create. Picture perfect web-of-life relationships occur in these spots, with fairy shrimp, salamanders, hawks, skunks, ducks, frogs, dragonflies and foxes all playing their part in the symphony.
We have had some striking successes in our efforts to preserve vernal pools. In Lucketts, just up Route 15 from Leesburg, is one of Loudoun’s great treasures, Gum Springs Wetlands. Loudoun Wildlife worked tirelessly with the private owners of the land where this globally-rare habitat is located, ensuring it was preserved by putting it into a conservation easement. That type of forward thinking is 21st-century preservation — the kind of conservation action that means you can look your grandchildren in the eyes and be proud you preserved the legacy and richness of the land and all its wild inhabitants.
Another of Loudoun Wildlife’s great victories was saving the pond adjacent to Rust Nature Sanctuary. We rallied to help get this land purchased and added to the Rust Sanctuary property. Now, years later, the sound of the frogs echo through the nearby woods on spring evenings, leading a wild orchestra in lovely vernal song. Read about the details of that achievement in the Spring 2008 issue of Habitat Herald from our online archive library.
We have experienced many heartbreaking losses as well, such as the pond on Tolbert Road, which were forever buried under an industrial building complex. Losses like those only strengthen our resolve to save what we can, when we can. Many pools were built over, before we even realized they were there.
Mike Hayslett, a vernal pool expert, has been by our side every spring for the last two decades. He has helped to make thousands aware of these rare environments, visiting schools, leading workshops and writing articles to help county residents understand the importance of these overlooked treasures. Mike also brought to our attention an insightful movie on the topic, Secret Pond: A Fairy Shrimp Documentary, which can be found on the internet by clicking here. We worked with Mike on another key success story where we created a complex of vernal pools along the Catoctin Ridge at Morven Park. We recognized through our monitoring that the amphibians were using road ruts created by hunters as vernal pools and that the historic vernal pool was failing hydrologically. So we got the Army Corp of Engineers approval to enhance the road ruts and turned them into functioning vernal pools that immediately became approved and used by Wood Frogs, Jefferson Salamanders and other obligate species.
The teamwork of Loudoun Wildlife and Mike Hayslett has created an immense, yet immeasurable impact on our mission. Mike consulted with us on most of our endeavors to save the pools, and he has been crucial in helping our members see just how far the web-of-life ripples extend from vernal pools. A good example of this is the relationship between fairy shrimp and the magnificent, migratory Wood Ducks. When the ducks fly south, they spy the vernal pools and land there for a rest stop. They drink the water, eat fairy shrimp, take shelter to rest, and then proceed with their migration. Particularly, they are giving back to the ecosystem when they eat female fairy shrimp and fly to another pool and defecate. The eggs of the fairy shrimp are then deposited in this distant pool, carried inside the duck droppings (known as endozoochory, or internal transport). The eggs have the remarkable ability to withstand many years of freezing winters and even the perils of a duck’s digestive system. If and when the conditions are right for the eggs (also known as cysts) to hatch, then they can start a new population with a rich genetic diversity.
Reptiles and amphibians are another foundation of food for many creatures. They thrive in vernal pools, and are abundant at the same time that hawks and owls are having their young. Frogs and Salamanders are a favorite of Red-shouldered Hawks, Barred Owls and many other raptors. When other food sources are scarce in late winter/early spring, vernal pools fill the gap perfectly.
We are sharing some of the highlights of the vernal pools and why they are important to humans and wildlife. We cannot capture nor completely understand all of the ways vernal pools are intertwined in our ecosystems, but we have known for the last 20 years that we need to save as many as we can to ensure the most diverse wildlife population. We first wrote about vernal pools in Habitat Herald in 1998. You can read that article on our website archives. Loudoun Wildlife and its partners, such as Mike Hayslett, will continue to sound the alarms to help remind people of our globally rare, natural treasures in Loudoun. Even at this writing, we are trying to save some local vernal pools. If you want to make a noble, bountiful, priceless investment for the wild legacy of Loudoun, then contact President Joe Coleman for details.
Interview with Mike Hayslett, Principal Consultant for Virginia Vernal Pools, LLC. Mike consults and educates for organizations and private land owners regarding vernal pool management and ecology. He can be reached at VAvernalpools@gmail.com.
http://www.ebd.csic.es/jordiplataforma/subidas/tesis.pdf . The role of waterfowl in the passive transport of aquatic organisms from local processes to long-distance dispersal.
https://www.loudoun.gov/index.aspx?NID=1373 A description of the karst terrain in Loudoun County, including maps.
Habitat Herald – Online Library Archives: