Filling critical springtime niche, vernal pools need our protection

A vernal pool formed in a yard near the Penns Creek in Snyder County.

​Averaging just an inch in length and four grams in weight, the spring peeper’s annual heralding of the spring season depends much more on sound than sight.

“For such a tiny tree frog, their high-pitched voices can carry up to a half-mile,” said Jon Beam, a master naturalist and outdoor educator at the Montour Preserve and vice president of the Montour Area Recreation Commission.

Not only does their call provide an important seasonal rite of passage, but provides a distinct audio reminder of the importance of vernal pools within our local ecosystems.

“The word ‘vernal’ refers to spring, and these pools are typically a springtime phenomenon,” said Beam. “They typically form where snowmelt – or a combination of rain and snowmelt – collect in a depression on the ground and stay there for a temporary period of time. It could be several weeks or maybe several months before a certain pool dries up depending on conditions.”

Certain species of frogs, toads and salamanders take advantage of these impromptu pools as critical breeding and egg-laying habitat. While spring peepers, among other species, can use other wetland environments to reproduce, other species rely completely on the presence of vernal pools for their survival. According to the Penn State Extension system, those “indicator” species include the marbled salamander, spotted salamander, Jefferson salamander, blue-spotted salamander, wood frog, Eastern spadefoot, fairy shrimp and clam shrimp.

“One of the advantages in using a vernal pool is that there are no predators for the frogs or salamanders or their larvae. These are temporary pools that can’t support fish or other potential predators throughout the year,” said Beam. 

“Also, because most of the vernal pools are in forested areas, a lot of leaf litter can be found at the bottom of the pools, which makes good cover for frogs and salamanders. In fact, some of them are so well camouflaged even on top of the leaf litter, unless they move, you can’t tell they are there. If something were to threaten them from outside the pool, they can quickly go under the leaves and disappear from sight very easily.”

Because many natural vernal pools are shallow and start forming before leaves develop on the overhead trees, the sun warms them very quickly.

“The warmer they are, the faster things can hatch and develop,” said Beam.

Triggered by spring rains and increasing soil and water temperatures, these amphibians seem to seek out pools with which they have an ingrained familiarity, according to Beam.
“They have a fidelity to a specific area where there is a vernal pool. Not a lot is known about where there is a lot of crossover from one pool to another from one year to the next – it can be difficult to track these little guys,” he said. “However, there seems to be a drive for them to return to the vernal pool where they are born.”

Which is why it is important to protect vernal pool areas, even after they are used for reproduction.

“If there are frogs breeding in the pool or either the egg masses or larva that have hatched from the eggs, destroying a vernal pool would cause them to die. Without water to support them, they would just dry up and die,” Beam said. “By removing a pool after breeding season, the next spring when frogs or toads or salamanders come back and can’t find the pool, they would have to travel farther to a new area and may not survive. Maybe they’d have to cross a road where they could get run over, or predators would pick them off or they just couldn’t find a suitable new place to breed.”

Identifying a vernal pool is a good first step in protecting it.

“You want to look for a shallow depression that holds water in the springtime. By summer, you likely wouldn’t realize it was there because it would lack water unless it was an unusually wet summer,” he said. “If you find a shallow pool with salamanders or frogs around it – or egg masses specifically this time of year – that would be a good indicator. If it has fish in it or excessive vegetation growing out of it, the feature likely isn’t a vernal pool.”

If you locate a vernal pool, the Penn State Extension system suggests taking the following measures to protect it:

• Do not drain or alter the vernal pool and carefully manage the area around it.
• Minimize the use of fertilizers, pesticides, and other chemicals that could travel to the vernal pool via runoff.
• Do not disturb the vernal pool in either the wet or dry season. Vegetation, fallen leaves, and woody debris are all important components of a healthy vernal pool and should not be disturbed.
• Protect the tree canopy so vernal pools remain shaded.
• Do not introduce or remove plants or animals.
• Document their locations using the Pennsylvania Vernal Pool Registry. It's a citizen-based program and is a rather simple process. The information in the data base will be available to researchers, landowners, and agencies managing these unique habitats.

​Wood frogs typically are the first amphibian to seek out the vernal pools, followed by spring peepers and eventually American toads. Once the creature mates and lays its eggs, it quickly leaves, according to Beam.

“They don’t stick around and watch over their egg masses. Once the young hatch and are able to leave, they are on their own – they are miniature versions of the adults at that time,” he said. “Once of the reasons most frogs and toads produce a lot of eggs in their egg masses is because not all of them will survive to adulthood. If one percent of them survive, that is pretty good.”

Beam recently found some unique vernal pools in the Bald Eagle State Forest, teeming with wood frogs and created in a unique way.

“They formed when glaciers were north of us. Because it was so cold just south of the glaciers, it caused paraglacial conditions, where there was a tundra-like situation with permafrost freeze and thaw cycles that formed about 20 of these vernal pools in that region,” he said, adding that vernal pools can even form in manmade structures.
​
“There was this old drainage ditch in a field. Not far from that ditch were several natural vernal pools, and over time, this ditch became one, as well,” he said. “It may have been manmade, but it served the purpose.”

Jon Beam talks during a recent Pa. Master Naturalist training session.

Check out an interview with master naturalist Jon Beam about vernal pools in our most recent episode of the Middle Susquehanna Riverkeeper Podcast:

Check out our growing library of podcast interviews with outdoor influencers from throughout our watershed by clicking here. Our list of guests include:

• Hellbender researcher Peter Petokas on trends in hellbender populations and how we can protect the species.
• Columbia County Conservtion District water specialist Brittney Hartzell on waterway issues within the county and the importance of stepping up to make a difference.
• PennEnvironment researcher Faran Savitz on a recent study that shows a microplastic proliferation in waterways across the state.
• Susquehanna Greenway Partnership's Corey Ellison on how her organization connects the region's land and water trails.
• Pennsylvania Master Naturalist director Michele Richards on the program and the impact of naturalists with our environmental resources.
• Bass pro and high school educator Casey Magaragle on his fishing exploits, Sneaky Hollow Bait Company and the thrill of coaching students to state and national fishing titles.
• Brenda Sieglitz on the Keystone10 Million Trees Partnership, how trees help clean up our waterways and the need for 1,300 new landowners to come forward for free trees from the program in the next year.
• Former state representative and senator Franklin Kury on his efforts to spark the Clean Water Act and Environmental Rights Amendment, the 50th anniversary of the movement and his new book due out soon. 
• Veterinarian Kathleen Mullen on her study involving sick foals and potential ties to fracking.
• Andrew Dehoff, of the Susquehanna River Basin Commission, on the group's 50th anniversary.
• Don Shappelle, musician, on creating river songs with young people and the Songs of the Susquehanna project.
• John Levitsky, water specialist for the Luzerne County Conservation District, on abandoned mine drainage at the Plainsville Borehole Discharge.
• Cain Chamberlin, of the Endless Mountains Heritage Region, on the Tunkhannock Creek's nomination for River of the Year.
• R. John Dawes, the creator of the Water Report app that allows anglers and others to share their catches and help us track health trends in our fish species.
• Kathleen Lavelle, of Trout Unlimited, on a unique fish relocation project she helped oversee, trout-based trends in the region and the importance of volunteering
• John Dawes, of the Foundation for PA Watersheds, on assisting smaller watershed groups, acid mine drainage and other waterway threats.
• ProtectNorthernPA.org founder Diana Dakey on her concerns about the production and transportation of liquified natural gas.
• Teen kayaker and angler Lila Oast on how kayaking has opened doors for her.
• Outdoor educator Jon Beam and Audubon member Gary Metzger with an overview of duck species and the threats they face in our watershed.
• Renee Carey of the Northcentral Pa. Conservancy on the importance of preservation and public access.
• Benjamin Hayes, director of Bucknell University's Watershed Sciences and Engineering Program on health of the river.
• Salmon angler Steve Kurian on benefits of clean water and fresh fish.
• Educator Van Wagner on his unique Eels in the Classroom program and the importance of eels.
• Waterkeeper Alliance Executive Director Marc Yaggi on growing up in the Middle Susquehanna watershed and his quest in the fight for clean water.
• Outdoor educator Jolene Connelly on the importance of getting youth and women on our waterways
• Diving instructor Rich Best on trends, treasures and threats under the Susquehanna
• Pennsylvania Organization for Watersheds and Rivers spokesperson Tali MacArthur on the importance of assisting a watershed group
• Falconer Mike Dupuy on raptors of our river and the threats they face
• Fish and Boat Commission spokesman Mike Parker on the agency's efforts during COVID and the historic unexpected start to trout season
• Wesley Forest Camp director Emily Sliski with stories of getting young people engaged with nature at camp and on the Penns Creek
• Professional angler and YouTuber John Oast on how he got his start, what he has learned along the way and observations of the river
• Biologist David Lieb on the concerning trend of exotic crayfish eradicating native species in our watershed and how it is impacting the ecosystem

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