Ranavirus, Amphibians, and How to Keep them Apart



Sometimes naturalists take precautionary steps just so they can do their job. Sometimes your help is needed to protect wildlife.

This past spring, May 2015, Old Colchester Park and Preserve experienced a wood frog tadpole die-off. Tadpole samples were submitted to the U.S. Geological Survey’s National Wildlife Health Center, which led to a positive test result for a strain of ranavirus.  This followed a 2014 Smithsonian study that returned an “unconfirmed positive” result for the same population of frogs.  Arlington County Parks Natural Resources Manager Alonso Abugattas noted that an Arlington park had an unconfirmed positive, and other parks in Northern Virginia that were part of the 2014 Smithsonian study also returned an “unconfirmed positive result.”

Ranavirus is a disease that affects amphibians, reptiles and fish.   It has never been known to infect humans.  The virus varies greatly in lethality, infection rate and symptoms.  Frog tadpoles, for example, show blood and lesions on the belly and around the hind limb buds and are usually only symptomatic during their development when hind limb buds are forming.  It is possible and likely that the virus has been present in our area for many years, but relatively little monitoring has been done in Northern Virginia.

With the confirmation of the virus at Old Colchester, naturalists from the Fairfax County Park Authority notified other area naturalists of the test results and urged them to take whatever precautions they could to protect wildlife in their parks and across the region. Amphibian populations or susceptible rare animals, such as wood turtles, could be affected by the disease, and there is no cure or direct treatment for it. In addition, parks with a lot of foot traffic in amphibian habitat could see their amphibian populations affected. To that end, FCPA recommended that school groups and citizen science workers also take precautions.

What are those precautions? The best action is prevention. That means halting the spread of the disease, and that means disinfecting boots, nets, containers and other gear before entering parks, vernal pools and ponds. That one step is the standard procedure for preventing the spread of ranavirus. Signs and publications, like this blog, also help make residents good stewards of nature.

Abugattas said Arlington County is taking precautions that include water sampling and macroinvertebrate surveys, noting that surveyers should follow proper disinfection protocols before moving to a new sampling site. Trained naturalists and support groups can help by monitoring wildlife population trends and watching for, what the professionals call, a “mortality event.” That’s generally considered five or more dead animals within the same population.

So scrub your boots, keep an eye on the environment, and report anything amiss to park staff.

More information is available from the Virginia Department of Game and Inland Fisheries. (www.vdgif.gov).


Author Owen Williams is a Natural Resource Specialist for the Resource Management Division of the Fairfax County Park Authority.

This entry was posted in Uncategorized on by .

About Fairfax County Park Authority

About Fairfax County Park Authority HISTORY: On December 6, 1950, the Fairfax County Board of Supervisors created the Fairfax County Park Authority. The Park Authority was authorized to make decisions concerning land acquisition, park development and operations in Fairfax County, Virginia. To date, 13 park bond referenda have been approved between 1959 and 2016. Today, the Park Authority has 427 parks on more than 23,000 acres of land. We offer 325 miles of trails, our most popular amenity. FACILITIES: The Park system is the primary public mechanism in Fairfax County for the preservation of environmentally sensitive land and resources, areas of historic significance and the provision of recreational facilities and services including: • Nine indoor RECenters with swimming pools, fitness rooms, gyms and class spaces. Cub Run features an indoor water park and on-site naturalist • Eight golf courses from par-3 to championship level, four driving ranges including the new state-of-the-art heated, covered range at Burke Lake Golf Center • Five nature and visitor centers. Also nine Off-Leash Dog Activity areas • Three lakefront parks including Lake Fairfax, Lake Accotink and Burke Lake, with campgrounds at Burke Lake and Lake Fairfax. The Water Mine Family Swimmin’ Hole at Lake Fairfax, Our Special Harbor Sprayground at Lee as well as an indoor water park at Cub Run RECenter • Clemyjontri Park, a fully accessible playground in Great Falls featuring two acres of family friendly fun and a carousel, as well as Chessie’s Big Backyard and a carousel at the Family Recreation Area at Lee District Park • An ice skating rink at Mount Vernon RECenter and the Skate Park in Wakefield Park adjacent to Audrey Moore RECenter • Kidwell Farm, a working farm of the 1930s-era at Frying Pan Farm Park in Herndon, now with historic carousel • Eight distinctive historic properties available for rent • A working grist mill at Colvin Run in Great Falls and a restored 18th century home at Sully Historic Site in Chantilly • A horticulture center at Green Spring Gardens in Annandale • Natural and cultural resources protected by the Natural Resource Management Plan and Cultural Resource Plans, plus an Invasive Management Area program that targets alien plants and utilizes volunteers in restoring native vegetation throughout our community • Picnic shelters, tennis courts, miniature golf courses, disc golf courses, off-leash dog parks, amphitheaters, a marina, kayaking/canoeing center • Provides 263 athletic fields, including 39 synthetic turf fields, and manages athletic field maintenance services at 417 school athletic fields. PARK AUTHORITY BOARD: A 12-member citizen board, appointed by the Fairfax County Board of Supervisors, sets policies and priorities for the Fairfax County Park Authority. Visit https://www.fairfaxcounty.gov/news2/social-hub/ for Fairfax County Government's Comment Policy.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s