Tag Archives: Huntley Meadows Park

Staff Manages Snakehead Threat At Huntley Meadows Park

Thirty-three Northern snakeheads were removed from the central wetland last fall.

Fifty Northern snakeheads were removed from the central wetland last summer.

One of the wildlife critters we’ll be keeping an eye on following the wetlands reconstruction at Huntley Meadows Park is the Northern snakehead. The exotic, predatory fish has been in the Dogue Creek portion of the Potomac River since at least 2004. They are well established in the Potomac River and have spread to other Chesapeake Bay tributaries. They were first seen in the Huntley Meadows central wetland in 2009.

Now, five years after the first sighting in the park and following the reconstruction that adds water depth to the central wetlands, there are new questions about the impact the snakehead will have at Huntley Meadows.

We sat down with the experts to get a better feel for the issue. Here are some questions and answers about snakeheads from that conversation with Huntley Meadows Park Manager Kevin Munroe, Huntley Meadows Resource Manager Dave Lawlor, and former Park Authority Resource Management and Protection Branch Manager Charles Smith:

Which species are most at risk from the introduction of snakeheads to the central wetland?

Smith: From our discussions about wetland management, the biggest concerns are the amphibians, particularly the frogs. Huntley Meadows has one of the only, and certainly the largest, breeding populations of southern leopard frogs in the region. There is concern that snakeheads could greatly reduce this population.

Lawlor: The native fish species will likely see the biggest impact from snakeheads.  However, after an electroshocking project last summer, the fish biomass and species abundance was very high and impressed everyone present, including the experts.  We do not know what kind of impact they are having on our amphibian populations.  The most significant impact would be the southern leopard frogs.  However, given the wetland project’s deep pool habitat created for fish and their predators (kingfishers, otters, bald eagle, grebes, etc.), all fish, including snakeheads, will probably experience more predation. This is a good thing, as it creates a more complete food web, and it may mean snakeheads experience more control from otters and eagles.

Staff use electro-fishing equipment to shock and count fish. Snakeheads are removed.

Staff use electro-fishing equipment to shock and count fish. Snakeheads are removed.

Is there any evidence that snakeheads are negatively impacting any species in the park?

Smith: There is no evidence yet.

At what age do snakeheads start having babies?

Lawlor: I believe they are sexually mature when they reach about 12 to 16 inches long.  We caught two here a couple of years ago, both around two to three pounds (17 to 20 inches), and they were both full of eggs.

Small schools of snakehead fry have been seen near the park.  Where would the adult female live?

Smith: In the same general environment – shallow water, often in vegetated areas.

Lawlor:  Females snakeheads of breeding age are living in the wetland complexes and likely in the central wetland along with many siblings and offspring.  Staff conducted an electroshock cull last summer while the wetland was drawn down for construction. Fifty snakeheads were removed from the wetland, including some large three to five-pound specimens.  Unfortunately, it appears snakeheads are here permanently, and we will have to continue to manage their populations.

Which animals eat snakeheads? Is it enough to control the snakehead population?

Smith: Wading birds, osprey, eagles, otter, snakes, and snapping turtles can all eat snakeheads depending on their size. It apparently is not enough to prevent snakeheads from breeding, but no one knows if there are enough predators to keep the snakeheads in check.

Lawlor: I would just add other fish, assuming other fish are able to survive in the wetland with them.  With the deeper pool habitat being created with the wetland project, other fish (crappie, perch, sunfish etc.) should have a chance to flourish in the wetland, too, and all of these fish eat other fish.

What should a person do if they spot a snakehead in Huntley Meadows? Is it ok to net and kill snakeheads on the boardwalk?

Lawlor: We ask people to notify us if they see a snakehead in the park.  We would prefer not to have the public randomly killing fish.  Not everyone knows how to ID a snakehead.

Is there a program in place to monitor snakeheads in the central wetland? 

Lawlor: I wouldn’t say we have a plan to monitor them, but they will be managed by removal whenever possible.  We are considering doing some removal this summer.

Are there any regularly scheduled culling dates?

Smith: Part of the design of the wetland restoration is to create deeper pools that can provide habitat for fish and other species during drought periods. During extremely low water, snakeheads should be confined to these pools. Park and county staff could then enter the pools with electrofishing equipment and remove all of the snakeheads in the pools while leaving the native species. This should provide the opportunity to greatly reduce the snakehead population every several years if not control them outright.

Lawlor:  We don’t have regularly scheduled culls, but we did a cull last summer and will continue to conduct culling operations when low water levels make it possible.

Is there a point at which we say, well, snakeheads are here, they may be non-native but they’re now a part of our local ecosystem?

Munroe:  We don’t know enough yet about the impact snakeheads have on our native ecosystems. They may turn out to be less of an issue than we originally thought, or they may be much worse. As we learn more, we can get a better handle on what our long-term approach and attitude should be.

Lawlor: I think that it is safe to say they are here to stay, after seeing the numbers of fish we removed from the wetland this past summer.  We have to accept that they are here, but we will do our best to manage the populations and keep their influence on our delicate ecosystem as small as possible.

What will deeper water in the wetland, one result of the reconstruction project, mean for the proliferation of snakeheads?

Smith: They can go where the water is, so snakeheads would follow the expanding pool during deeper water periods.

Lawlor: Also they would be able to survive the most severe droughts that would normally kill off their population. So the deeper water will ultimately benefit their populations in the wetland. But as Charles mentioned, this will be an opportunity for staff to manage their number by catching or shocking them in the deep water pools as we did in summer of 2013.

How big can a snakehead grow in the central wetland?

Lawlor: This is still unknown in the wetland system.  A record snakehead was caught in the Potomac River in 2013, around 17 to 18 pounds.  I am not sure they will be able to get that big in the wetlands because they will not have nearly as much forage – if they stick to fish.  So far the biggest snakehead caught in the central wetland was about five pounds.

Bowfin, lamprey and American eel look a little like snakeheads. Are those fish seen in Huntley Meadows?

Munroe: American eels yes, but not the other two species. However, eel have uniformly brown backs and sides, while snakeheads are patterned with black blotches on a pale background, much like a python, hence the name.

Former Huntley Meadows Park staff member Danielle McCallum holds a 17” Northern snakehead caught while electro-fishing Dogue Creek in 2008.  This was the first snakehead caught in the park.

Former Huntley Meadows Park staff member Danielle McCallum holds a 17” Northern snakehead caught while electro-fishing Dogue Creek in 2008. This was the first snakehead caught in the park.

Lawlor:  American eels are common in the Dogue Creek and Barnyard Run watersheds.  The least brook lamprey is also found in the Dogue Creek Watershed, although none have been found in the wetland yet.  Least brook lampreys are typically less than six inches in length.  As Kevin mentioned, eels and lampreys are generally a solid brown or tan and do not have any patterns on their flanks making them easily distinguishable from snakehead fish.  I am not aware of any positive ID of a bowfin in Fairfax County, but they are found in some Virginia rivers.

Can people fish for snakeheads in Huntley Meadows?

Munroe: No. Fishing is not allowed at Huntley Meadows Park.

Is it safe to say that snakeheads are breeding in the central wetland?

Lawlor: Yes!  We will continue to manage their populations the best we can to reduce their influence on the wetlands ecosystem.

Prepared by Matthew Kaiser, deputy public information officer; and Dave Ochs, stewardship communications manager.

Wetland Restoration Project Starts to Sing!

The wetland restoration project at Huntley Meadows Park is nearly complete.

The wetland restoration project at Huntley Meadows Park is nearly complete.

After 22 years of planning, three environmental engineering firms, numerous design drafts, and more than 60 public meetings, it’s hard to believe that the Huntley Meadows Wetland Restoration Project is just days from completion. As Fairfax County Park Authority  staff struggle with the challenges of directing contractors, managing finances, unpredictable weather and inevitable construction delays, the park’s wildlife have decided to ignore all these silly human issues and literally dive into the project.

First, a little context

Raising and then managing the wetland’s water levels in order to maintain a hemi-marsh full of biodiversity is the project’s primary goal. The wetland has been slowly, steadily losing depth for several decades because of silt and cattail spread. It lost almost a foot of depth since the 1980s. That’s one-third of its water, since it was never more than about three feet deep.

The restoration design has three main aspects — creating an earthen dam with a vinyl center to regain that lost foot of depth, installing pipes to create seasonally fluctuating water levels (essential for maintaining a healthy hemi-marsh), and excavating several deeper pools to create refuge for wetland wildlife during summer droughts and winter freezes. As an added plus, the project doubles the wetland’s boundaries, seasonally flooding surrounding forest to create additional swampland and vernal pools. Combined, those events restore a paradise for wildlife and wildlife watchers.

At least that was the idea. But would it work? Would 22 years of planning pay off? Would park wildlife agree with and adopt the design, or would we end up with a beautiful but empty wetland as animals high-tailed it for other parks not full of excavating bulldozers, 20-person construction crews and enough silt-fence to surround a small country? I’ve been telling people that three years was a good amount of time to wait until we saw real results. It turned out all the wetland needed was seven days of rain.

Seven days, not three years

Remember back in mid-October when it rained non-stop for a week? Well, the construction was far from complete, but the dam and pipes were finished. So we were able to raise the water level back to its 1986 levels plus an additional 10 inches. Wetland boundaries expanded, areas were submerged that had been dry for 30 years, and then we waited, watched, and listened. As park staff struggled with submerged trails and a small section of boardwalk that flirted with the idea of floating away, wildlife chose to ignore these mundane issues and had a ball.

Huntley’s resource manager, Dave Lawlor, and I were walking the trails to determine which sections to raise when we heard what sounded like the roar of a low plane moving towards us over the flooded wetland. The roar got louder, Dave and I had to shout to hear ourselves, but when we looked around — no plane in sight. Then we realized the deafening sound moving like a wave across the wetland was the largest chorus of southern leopard frogs we’d ever heard. One male frog starts to croak, cackle and gargle, his neighbor feels competitive and tries to outdo him, his neighbor does the same, and in seconds the sound wave rolls across 40 acres of wetland, echoing into the surrounding forest. The extreme volume was due to the increased wetland footprint. This was the largest the wetland had been in over 30 years, creating an enormous stage for one of Northern Virginia’s least common frogs and one of the species we had hoped to help with this project. “Build it and they will come” and sing.

Photo by Ed Eder

Southern leopard frogs, one of the least common frog species in Northern Virginia, are already benefitting from the expanded wetland.

The return of the birds

Wonderfully, and thankfully for an anxiously waiting park manager, southern leopard frogs were not the only wildlife that adopted and utilized the restored wetland. One morning as I joined Charles Smith, FCPA’s lead naturalist and resource protection manager, to inspect the project, we heard a warbled, bouncy bird call coming from the edge of a recently excavated habitat pool. “Purple finch? Goldfinch? No, I think it’s a winter wren!” A tiny, mouse-like bird that flits down from New England to spend its winters hiding in the moist thickets of the mid-Atlantic had its head thrown back and was singing its heart out from a wildlife brush shelter constructed only days before.

Unfortunately, a few hundred trees had to come down in order to create the new dam, pipes and pools. Our goal was to use all of those trees on-site as habitat enhancements (brush shelters, sunning logs for turtles, underwater breeding habitat for crayfish, etc.), and winter wrens were one of the species we were hoping to attract.

That same morning we heard several belted kingfishers throwing their rattling cries across the wetland, diving for fishy snacks in the newly excavated pools, and over the last few weeks numerous ducks have appeared to feed, court and mate in the expanded wetland. Northern shovelers, northern pintails, green-winged teal, and American black ducks are just a few of the winter waterfowl species now in the wetland, visiting from their summer homes in Canada and our upper Midwest.

None of the species I’ve mentioned so far, from frogs to ducks, are new to Huntley, but their numbers appear to have increased this fall/winter because of the larger wetland and historic water depth. Our goal was never to attract new species, but rather to return the marshland wildlife back to their 1980s numbers, and to convince rails, bitterns and grebes to nest here again as they did several decades ago. Will king rails and pied-billed grebes build nests and give birth again to new generations next spring and summer? We’ll see or, more accurately, we’ll listen.

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Mike Rollband, president and owner of Wetland Studies and Solutions Inc., discusses the wetland restoration project.

Author Kevin Munroe is the site manager at Huntley Meadows Park. See more photos of the project on Flickr.

Photobombing Coyotes and Other Things That Go Bump in the Night in Parks

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Most people around Northern Virginia probably don’t get to see what wildlife is doing on a daily basis, and there is a lot of wildlife here. The Fairfax County Park Authority has several ways of connecting people and wildlife, such as nature centers and hiking trails. One of the fun methods of connection is the candid camera.

Since January, Riverbend Park staff has been conducting a camera-trap survey to learn about wildlife in that park. Cameras with infrared sensors that detect both heat and motion, called trail cameras or game cameras, are placed along wildlife trails. When an animal drifts by and breaks the infrared beam, the heat or motion triggers the camera, which can be set to record one or multiple frames. The boxes can be fitted with an infrared flash that will limit any disturbing of the animals. And the cameras can be programmed with a delay of five or ten minutes between shots so that the same animal isn’t photographed dozens or hundreds of times while hanging around.

Staffers never know exactly what to expect each time they check the camera storage cards. Riverbend features a large meadow, a riverbank, creeks, ponds, and deep forests — diverse habitats. These combine to host a wide range of wildlife. Sometimes thousands of pictures reveal nothing. Other times, there are pleasing surprises.

Among Riverbend’s photobombing animals are coyotes, which confirms their presence in the park.

The most common visitors strolling past these cameras have been white-tailed deer, raccoons, and gray squirrels. Foxes and otters also have stopped by for portraits. Riverbend Head Camp Counselor Brian Balik, who uses his own cameras to record some of the photos, says his favorite picture so far has been that of a red fox with white legs. Those are unusual markings and something he’s not seen before.

This fox has unusual markings.

This fox showed off its unusual white legs for the camera at Riverbend Park.

The value in these photos is in learning what animals are around. That helps staff know what steps to take to protect the wildlife. Years ago, people had to rely on actual sightings of animals. Now, staff can see exactly what is in a specific area 24 hours a day, seven days a week.

The cameras also reveal animal behavior. They record the times the animals are awake, the population, the areas of a park they use, and how frequently they use particular areas. Riverbend staff is hoping the cameras will help them learn where the visiting coyotes live and whether their home is in the park.

Ellanor C. Lawrence Park (ECLP) in Chantilly also has conducted camera-trap surveys, and a coyote has been a common visitor there as well. ECLP Naturalist Tony Bulmer says that in late September that coyote brought along a friend, and he suspects the pair may hunt together. Coyotes do not travel in packs, like wolves, but rather they move about separately or in a family unit. ECLP is hoping their cameras will have more to teach about the coyotes, a species that Bulmer calls “one of the most maligned mammals in the United States.”

Huntley Meadows Park staff used four infrared cameras in 2011 to survey the population of deer at Old Colchester Park on Mason Neck.

Huntley Meadows Resource Manager Dave Lawlor analyzed almost 4,000 photos in the Old Colchester survey, and he pointed out that reviewing them on a computer became a little strange because, since the camera doesn’t move, the background of the photos never changes. “It makes your eyes go fuzzy after a while,” he said. Lawlor used antler points and branches to identify individual bucks, but identifying individual does is much harder.

The Old Colchester survey, possibly the most thorough one ever conducted on Mason Neck, revealed an estimated population of up to 60 deer in the 139-acre park, the equivalent of 278 deer per square mile – a lot. Naturalists estimate that the healthy population of deer in an eastern forest is 15 to 20 per square mile.

Another survey was conducted at Old Colchester this fall, and those photos will be analyzed over the winter.

Huntley Meadows Park Manager Kevin Munroe said that Northern Virginia has an overstock of deer because there’s often much more food available for deer in a suburban setting than in a pristine forest. Lawlor added the amount of nutrients deer can ingest in suburbia could be ten times that of a forest and that people think fertilizer feeds plants. He said fertilizer is nutrients for deer.

The large number of deer also affects forested areas. Some parkland has virtually no vegetation for four or five feet up from the ground except for invasive plants that deer won’t eat.

Information like this, plus the input from the trail cameras, can be used as part of the structuring of a deer management plan.

Oh, and those coyotes are widespread across the county, too. The Old Colchester survey also turned up a photo of a coyote on Mason Neck.

Riverbend Park Head Camp Counselor Brian Balik, Huntley Meadows Resource Manager Dave Lawlor, and Stewardship Communications Manager Dave Ochs contributed to this story.

Interns, Invasives, Introductions, Identifications

 

Interns Caitlin Lundquist  (right) and Melissa Letosky spent the summer in the field.

Interns Caitlin Lundquist (right) and Melissa Letosky gathered data in the field.

There’s a lot going on in this job! Prior to my internship with the Fairfax County Park Authority, natural resources were an abstract concept for me. Although I considered myself to be a pretty outdoorsy person, I now realize I was practically blind to the nature around me until this experience opened my eyes to the amazing life it contains. I was born, raised and educated in Northern Virginia, and even though I am studying environmental sustainability, I knew so little about the environment in my own backyard. This internship provided the best education I have ever had about the ecosystems in which I’ve lived.While I have volunteered for invasive plant removals in the past, this summer I was able to work on a long-term project to protect the local forest from non-native invasives. Throughout the internship, another intern and I surveyed more than 5,000 acres of forested parkland, focusing on the degree of non-native invasive infestation. The most diverse, undisturbed and publically valued forests receive higher priority rankings and are targeted for invasive treatment and further preservation efforts. This rating system helps the Park Authority’s natural resource managers determine how to efficiently allocate forest conservation funds. By approaching invasive management from a different perspective this summer, I learned about the details that make such large efforts successful.

The job as a Natural Resources Intern was packed full of a variety of learning opportunities. Right off the bat, I was taught how to identify non-native invasive plants, signs of a healthy forest, and a good number of common native forest plants. I also had the invaluable experience of working daily with geographic information systems (GIS) to make maps and log points in the field for data use. The interns attended an introductory GIS 101 class to gain additional technical skills.

In addition to this everyday hands-on experience, I had the opportunity to participate in deer browse surveys, vegetation plot analyses, rain garden maintenance and water quality assessments. Through experiential learning, I was educated about multiple conservation efforts that the Natural Resources Management Protection Section handles. For example, I was able to see why the overpopulation of white-tailed deer was such a problem when shown the baby oak trees they had hedged down to the ground.

While I became most familiar with forest ecosystems, I also learned a lot about wetlands and meadows. At Huntley Meadows Park, we toured the wetland restoration project, walking along the construction site to conduct water quality testing. We also spent a week assessing non-native species in the woods. Another special event the interns were fortunate to attend was a grass identification class held by a group of volunteers, where we were introduced to the huge variety of grasses, sedges and rushes in local meadows. Finally, an insightful talk by University of Delaware professor and author Doug Tallamy, a well-known native plant expert, stressed the importance of native biodiversity in all ecosystems.

I am currently going into my last year at George Mason University and am constantly thinking about what I want to do as a career. This internship has introduced me to a different aspect of the local area and to environmental protection in general. I have learned tons about how the county is organized and functions and am thankful to everyone I worked with for being so nice and willing to share their knowledge and resources. Working outdoors to improve the environment in my hometown has been extremely rewarding and has inspired me to improve my scientific and natural resources education.

 Author Caitlin Lundquist was an intern for the Park Authority’s Resource Management Division in the summer of 2013.

 

The Improbable Mr. Wilson: A Tale Of A Wandering Warbler

There has been a lot of chirping about a little yellow bird at Huntley Meadows Park recently. Ever since a Wilson’s warbler was unexpectedly seen during the Audubon Society’s annual Christmas bird count on Sunday, December 30, staff, volunteers, and visitors have been curious about the bird’s origin. A tiny patch of orange plumage above the bird’s beak sparked a debate and led to the endearing moniker, The Improbable Mr. Wilson.

Meet The Improbable Mr. Wilson.

Meet The Improbable Mr. Wilson.

According to park manager Kevin Munroe, Wilson’s warblers, like most warblers found in the park, are neo-tropical migrants, which means they breed somewhere in the northeastern U.S. and Canada each spring and summer before traveling south to spend their winters in Mexico, Central America, or South America. Munroe says it’s not unheard of to see a misplaced migrant at this time of year, but they typically either move on or expire due to a lack of food sources. For a specialist in hunting insects like Mr. Wilson, January in Northern Virginia is a tough place to find a meal.

However, Mr. Wilson has proven to be a resourceful visitor. Since his first sighting, scores of people have reveled in the sight of the wandering warbler feeding at the birdfeeders next to the visitor center. He has managed to avoid the hunting hawks and was photographed chomping on a caterpillar. Mr. Wilson has also been seen feeding on Sweetgum seeds along the paved trails. As people inadvertently step on the spiky pods, Mr. Wilson swoops in to munch on the released seeds.

Wilson's Warbler by Dave Boltz

The Improbable Mr. Wilson snacks on a caterpillar.

One theory about Mr. Wilson’s visit is that he is filling up for a late departure for the Southeast U.S. or the Gulf Coast, where he could survive on seeds, berries, and any available insects. But it is the presence of the bright orange markings visible in the many high-quality photos being shared online that have birders wondering if Mr. Wilson may have traveled from the west, not the north.

The bright orange patch above Mr. Wilson's beak caused quite a stir.

The bright orange patch above Mr. Wilson’s beak caused quite a stir.

After seeing the orange forehead in a photo, longtime birder Bill Young exclaimed, “Mr. Wilson appears to be even more improbable than he seemed at first glance.” Young has had many close looks at Wilson’s warblers in the past, but doesn’t recall ever seeing the orange marking. He and Paula Sullivan consulted the Garrett and Dunn warbler guide and found that there are three varieties of Wilson’s. Of the three, only one displays the orange markings, the chryseola. They learned that the chryseola variety breeds along a narrow band of the West Coast, from southern British Columbia to Southern California, and winters in Mexico’s Baja Peninsula and south to western Panama.

This revelation led Young to declare, “So Mr. Wilson is most likely not an eastern or central bird who is a little late and a bit off course; he probably came from the other coast of North America, which is a pretty amazing trip for a creature who weighs about a quarter of an ounce.”

Huntley Meadows volunteer and avid bird buff Larry Cartwright, known among birding circles as an expert, concurs with Young’s assessment.  “I think this vagrancy from the west happens frequently. We had a dark yellow warbler that turned out to be one of the dark western subspecies, and there is quite a number of Rufous/Allen’s hummingbirds reported this year and they are all from the west. So Bill is absolutely right.”

Although Munroe is confident the wandering warbler began its journey on the West Coast, he said, “We can’t exactly check his passport, so we’ll never really know.” He remains open to other theories and welcomes discussion.

Mr. Wilson was last seen in the park on Wednesday, January 2. The birders who were fortunate enough to have seen him are grateful for his improbable visit and wish him a safe journey home – wherever that may be.

Thanks for stopping by, Mr. Wilson.

Thanks for stopping by, Mr. Wilson.

Written by Matthew Kaiser, deputy public information officer

Advancing Northern Snakeheads Thwarted at Huntley Meadows Park

Resource Manager Dave Lawlor shares the history of Northern Snakeheads in Dogue Creek and recounts a close call with this invasive fish at Huntley Meadows.

Former Huntley Meadows Park staff member Danielle McCallum holds a 17” Northern Snakehead caught while electro-fishing Dogue Creek in 2008. This was the first snakehead caught in the park.

Huntley Meadows Park, a 1,500-acre complex of freshwater marshlands located in Alexandria, Va., has long been a destination for birders, wildlife photographers, and students. No matter the season, people flock to the boardwalk trail to observe migrating birds, soaring raptors, moss-covered turtles, beavers, delicate dragonflies, and many more species in the park’s 50-acre central wetland, the largest in the region. Freshwater wetlands are considered rare habitat in the Washington, D.C. region and harbor the greatest biodiversity of any habitat type in temperate climates. However, in recent years Huntley’s central wetland has come under threat from an invasive fish species, the Northern Snakehead. If allowed to breed within the park, with their voracious appetites snakeheads have the potential to wreak havoc on the park’s large populations of amphibians, reptiles, birds, and mammals.

Listed by the state Board of Game and Inland Fisheries as a predatory and undesirable exotic species, snakeheads have been slowly migrating from the Potomac River up Dogue Creek toward the central wetland since 2004. Nine snakeheads were caught in the tidal section of the creek that year, and a year later two fishermen caught more than 80 young fish only a mile and half downstream from the park. Once snakeheads were found in the non- tidal sections of Dogue Creek, park staff became very concerned and took action to try to protect the central wetland from invasion.

Northern Snakeheads have razor sharp teeth.

In 2006, the Resource Management staff at Huntley Meadows requested staff from the Watershed Planning and Assessment Branch of the Department (WP&AB) of Public Works and Environmental Services (DPWES) conduct an electro-fishing survey of Dogue Creek at the park’s southern tip.  Electro-fishing doesn’t kill the fish but renders them immobile for several seconds, enabling staff to net, identify, and count the fish before releasing them.  With this survey, staff attempted to determine if snakeheads had made the mile and half migration up the creek from the Route 1 overpass where 80 snakeheads had been caught the year before.  Unfortunately, one 17” snakehead was caught inside the park just as the shocking crew was finishing for the day.  Although just one fish was caught, it was evident that snakeheads had made the long upstream migration and were only about one mile below Huntley’s central wetland.

Heather Ambrose, Shannon Curtis, Eric Forbes
and Dave Lawlor shock, net, and count fish in Dogue Creek at Huntley Meadows Park in 2010. No snakeheads were found during this survey.

In 2007, staff conducted another electro-shocking survey in Dogue Creek at Wickford Park, which is about one mile upstream from where the 17” snakehead had been caught in 2006. This section of the migration would be much tougher to navigate due to shallow wetlands that periodically dry up as well as multiple beaver dams that impede migration.  Although no snakeheads were found during the survey, park staff and visitors began to see snakeheads in the central wetland in 2009 and 2010. Two of these fish were very young, indicating snakeheads were either reproducing in the park or immigrating into the wetland from Dogue Creek. 

During the spring of 2011, Huntley Meadows Park patrons and volunteers reported seeing a large snakehead in the central wetland along the boardwalk just past the loop.  Soon reports were coming in almost daily and the snakehead number doubled when two large snakeheads were seen in a ditched portion of the wetland, right on top of the water. Immediately park staff jumped into action and tried to net the fish, but these large fish were elusive.  Park staff became very concerned that the fish would breed in the wetland, potentially releasing hundreds or thousands of baby snakeheads which could take over the central wetland and wreak havoc on the wetland’s incredibly diverse aquatic populations. 

Two large snakeheads were netted in the central wetland at Huntley Meadows Park in 2011.

Shannon Curtis and Chad Grupe from the WP&AB were contacted. These folks live and breathe water quality and are sought after professionals when it comes to fish and anything that lives in Fairfax County waters. They brought their electro-fishing backpacks to the park to try to help catch the two large snakeheads before they started upsetting the wetlands sensitive ecologic balance. Within an hour they caught two large snakeheads measuring 20” and 25”. 

After another hour or two of searching no more snakeheads were located in the wetland and the search was called off.  Both of the large snakeheads were females and they were packed full of hundreds of eggs.  As required by state law, the fish were destroyed.  Staff examined the stomach contents and the large fish’s stomach contained a large goldfish (Carassius auratus) and the smaller fish’s stomach contained a smaller fish or tadpole of an undetermined species due to nearly complete digestion.  

Huntley staff continues to be diligent in the search for more snakeheads and we expect this will be a long-term battle.

Dave Lawlor, natural resource manager, Huntley Meadows Park

The severity of the Northern Snakehead problem was made clear this summer when, during a survey at Old Colchester Park and Preserve, Park Authority staff spotted this dark cloud in a tidal marsh near the Occoquan River. It was identified as a “fry ball,” or a group of 10,000-15,000 newly hatched snakeheads.

Controlled Burning as a Management Tool for Fairfax County Parkland

One of the characteristics of human culture is our control and use of fire. But even though it is an essential tool, unplanned fires can take human lives and damage property; so fire suppression has been a common practice for over 100 years in the United States.

Although most people don’t realize it, almost every ecosystem in North America is fire adapted – it has species and processes that rely on periodic fire to maintain their health. This is true of forests as well as fields.

The Fairfax County Park Authority began using fire in 1997 to manage meadows. These grass-dominant systems flourish if burned as regularly as every one to three years.

Controlled (prescribed) burning is a common management practice throughout Virginia. As stated by the Virginia Department of Forestry in Virginia’s Smoke Management Guidelines, “The use of prescribed fire as a resource management tool has long been regarded as indispensable.” The Virginia Department of Forestry, Department of Game and Inland Fisheries, Department of Conservation and Recreation, USDA Forest Service, National Park Service, The Nature Conservancy, etc. – in short, almost every entity that owns and manages natural areas in the state – all conduct prescribed burns annually in forest and field environments. According to the National Wildfire Coordinating Group, over eight million acres each year are managed using prescribed burns in the southern United States alone. Burning is considered a standard, highly-effective maintenance practice.

Most eastern ecosystems evolved with fire as an integral part of their lifecycles. In meadows, fire removes accumulated plant debris, heats the seed-bank in the soil, and exposes soil to sunlight.  These actions allow native plant seeds to come in contact with the soil, make nutrients available to the plants, remove old material that inhibits new growth, and promote and allow new plants to sprout. Fire also helps to suppress many invasive, non-native plants (e.g., tall fescue) that did not evolve with fire as part of their lifecycles. The result is a healthier plant community that supports a greater diversity of plants, animals and other organisms. No other maintenance method can provide the habitat benefits that fire does in meadow systems.

Given the fact that meadows are the fastest disappearing habitat type inFairfax County, preservation of the few remaining large meadow complexes through proactive means should be a priority. Burning is considered the best way to manage meadows for the health of the system and to prevent future fires by eliminating fuel that cannot be properly removed by mowing.

The successful burns at Riverbend Park in 1997 and Ellanor Lawrence Park in 1999 demonstrated that fire can be used safely in Fairfax County without adverse effects on human property or activities. In both of those cases, well-planned fires were conducted in partnership with Fairfax County Fire and Rescue and the Virginia Department of Forestry in small meadows in relatively close proximity to homes and public roads. The fires not only were accomplished without complication, but there were no complaints from neighbors and the public who responded positively to educational materials and programs which discussed the controlled burns.

The Park Authority formalized its prescribed burn program in 2006. The controlled fires support state rare species that rely on meadow habitats and a great diversity of wildlife including grasshopper sparrows, eastern meadow voles, black racer snakes, red foxes, owls and northern harriers. Each year fields ranging in size from a few acres up to 40 acres are burned at multiple parks. The most recent burns occurred in February and March 2012 at Laurel Hill Park in Lorton, Elklick Preserve west of Centreville, and Ellanor C. Lawrence Park in Centreville.

Written by Charles Smith, manager, Natural Resource Management and Protection Branch