Fishing the Fort: National Park Service and Penn State scientists find notable fish in tiny stream (copy)
Ben Moyer
Morgan Stum (left), a graduate student in Wildlife and Fisheries at Penn State, and Caleb Tzilkowski, National Park Service aquatic ecologist, use electro-fishing gear to survey fish in Great Meadows Run, Fort Necessity National Battlefield.
Ben Moyer
Morgan Stum (left) and Caleb Tzilkowski, affiliated with the National Park Service Eastern Rivers and Mountains Network, photograph a fish captured in Great Meadows Run. Photographs replace the old practice of preserving specimens in museum jars.
Ben Moyer
National Park Service aquatic ecologist Caleb Tzilkowski displays a white sucker temporarily confined in a “photarium,” a special chamber used to make scientifically valid photographs of fish specimens.
When visitors to Fort Necessity National Battlefield in Farmington enter the park, its crude fort, British flag, and light artillery aimed toward the woods command their attention.
Few notice a small meandering stream that snakes through the Great Meadows and under a footbridge on its way to meet Meadow Run and the Youghiogheny River downstream. That little creek is Great Meadows Run, and it likely carried away blood from some of George Washington’s killed and wounded troops during the 1754 battle there with French and Indian forces.
But scientists with the National Park Service and cooperating universities do notice the little stream. Caleb Tzilkowski is an aquatic ecologist with the National Park Service, and Morgan Stum a graduate student working toward a Master of Science degree in Wildlife and Fisheries at Penn State. Both work within the Park Service’s Eastern Rivers and Mountains Network ecological monitoring program, which assesses plant life, birds, mammals, reptiles, amphibians, and fish on nine National Park Service sites in Pennsylvania and West Virginia. On Tuesday, Sept. 19 Tzilkowski and Stum surveyed Great Meadows Run at Fort Necessity to document what lives in its waters.
“We survey 78 different study sites throughout the nine national park tracts in our Eastern Rivers and Mountains Network,” Tzilkowski said. “We survey the exact same sites to track how things are changing, or not changing, through time.”
Scientists with the Network study elements of the parks’ ecosystems on different rotating schedules. Some living component, such as birdlife or vegetation, is monitored every two years. They last surveyed fish at Fort Necessity in 2013.
“Fishes are often overlooked as part of an ecosystem,” Stum said. “We’ve seen it in many of our parks. Visitors will look at some small stream and say there can’t be fish in there.”
She and Tzilkowski set out Tuesday to learn if fish do continue to live in tiny Great Meadows Run, including some notable past finds. Stum strapped on a backpack with a lithium battery connected to a negatively charged “rattail” cathode that trails in the water behind the user. She held a long pole, also linked to the battery, with a positively charged anode ring at the end. When Stum touched a trigger, the system sent a mild electric current through the water nearby. Any fish within reach of the charge are temporarily stunned but not injured. Biologists call the technique “electro-fishing.”
The team crept slowly upstream along the 100-meter study site, Stum probing ahead with the anode ring, while Tzilkowski trailed with a long-handled net and bucket to collect their catch. Each time Stum hit the trigger, a mild “buzz” hummed out of the system and a red light on her backpack shone in the deep shade. At nearly each “buzz,” small fish flashed in the current ahead, then wriggled to the surface, “belly-up,” where they were netted and eased into water in the bucket.
“Morgan handles these fish differently than when I was trained,” Tzilkowski said during the captures. “Not so long ago, we preserved specimens in museum jars for study collections. Now, Morgan uses a high-resolution camera to photograph the specimens in a “photarium,” which confines the fish and provides grids for measuring. She gets sharp photos that are as valid as preserved museum specimens, but the fish aren’t killed for science. We call them ‘digital vouchers.'”
Interestingly, Tzilkowski explained that scientists using this equipment always photograph a fish’s left side. “It’s just scientifically consistent to do it that way,” he said.
When Stum and Tzilkowski reached the upstream end of the study span, they deployed two small nets on the stream bottom, weighted by rocks, but with their rims above the water, so fish couldn’t escape. Tzilkowski dumped their entire catch from the bucket into one net. Stum lifted out each fish, announced its species and approximate age (adult or “young-of-year”), while Tzilkowski recorded the data on a clipboard. Stum then dropped the noted fish into the other net.
After they’d recorded each fish, Stum placed them back in the bucket and walked back downstream, releasing all the fish at various points.
“They’ll be back in their favored habitats in minutes,” Tzilkowski observed.
Total fish captured by the team in a 100-meter section of Great Meadows Run included: 20 blacknose dace, 29 creek chubs, 6 white suckers, 10 johnny darters, and 1 mottled sculpin.
Dace and chubs are members of the vast minnow family, and darters belong to the perch family. Fishermen often assume that suckers are an indication of polluted waters, but some suckers live only in pristine habitats.
In 2013, surveyors found one largemouth bass in the stream. “It likely escaped from some pond in the watershed,” Tzilkowski said.
The team’s most significant find was the mottled sculpin, a small, broad-headed and big-mouthed fish that lives on the bottom. “[Great Meadows Run at Fort Necessity] is the only one among our 78 study sites in nine parks across two states where we have found this fish,” Tzilkowski said. “We’ve found it here in our previous surveys, and its presence is a strong indicator of cold, clean water. It can’t live in warm habitats. The fact that it’s still here tells us this is good water, from the standpoint of temperature and chemistry, and that things haven’t changed much since 2013. But this fish would likely be more abundant here if the physical habitat were improved. The sculpin likes a gravelly, complex bottom, but this stream is heavily silted from two centuries of agriculture before this was a national park. With better physical habitat here, this stream could support a population of native brook trout, which were likely here at the time of the battle.”
“Without this monitoring work from the Eastern Rivers and Mountains Network, we wouldn’t know this fish was here,” said Brenda Wasler, natural resource manager at Fort Necessity. “It may influence how we manage and work to restore this stream in the future.”
Ben Moyer is a member of the Pennsylvania Outdoor Writers Association and the Outdoor Writers Association of America.