Brush Creek monitors find fair to poor water
Courtenay Vass steered her Jeep onto the shoulder of the road near a rolling open space smack in the middle of tony suburban Greensboro. She opened the lift gate and pulled out the day’s supplies: three pairs of wading boots, a long-handled net, plastic tubs, Petri dishes, test tubes, thermometers and a clipboard.
Her daughters, 14-year-old Whitney and 11-year-old Austin, climbed out of the car and traded their sneakers for the dark rubber boots. Under clear skies, on an unseasonably warm December day, the family set off across a grassy field and down a slope toward Brush Creek.
The Vass family has been driving out this way for the past six years, in regular three-month intervals, monitoring the health of this gurgling creek as it winds between Piedmont Triad International Airport and the Haw River. Recruited by the Haw River Assembly, the Vasses are one of a small number of river watchers in Guilford County who monitor the health of an aquatic ecosystem increasingly threatened by pollution from development and wastewater treatment.
“Our water quality is usually fair or poor,” Courtenay Vass said. “It’s never been good.”
Whitney Vass extracted a thermometer from her load. She left it, dangling from a shoelace on a nearby branch. Meanwhile Austin Vass was bent over double, scanning a silty island for signs of wildlife.
“There’s raccoon prints here and dogs,” she announced.
Whitney Vass dutifully marked everything onto a worksheet. Then they set to the task at hand. Austin Vass selected a particularly promising looking rock and dumped it into a tub along with some of the creek water. They set about poking and prodding, trying to flush out macroinvertebrates, water-dwelling insects and crustaceans large enough to see with the naked eye.
“Alright, think like a macroinvertebrate,” Courtenay Vass said.
The bugs favor rocks, leaves and overhanging shores, and their presence, or rather the diversity of their presence, indicates a great deal about the livability of the stream. Creatures like damselflies, stoneflies and red worms are divided into three groups – pollution sensitive, somewhat pollution sensitive and pollution tolerant. River watchers like the Vasses try to identify as many different types of critters as they can in 30 minutes.
“Even though I’ve been doing this for six years I still question myself sometimes,” Courtenay Vass said.
The Haw River Assembly provides all the materials the Vasses need to monitor Brush Creek, including a helpful laminated chart of illustrated macroinvertebrates. Several of the animals looked similar and, being tiny, were only distinguishable by slight variations in physique.
Whitney slipped one into a Petri dish and peered at it through a magnifying glass. Feathery, translucent gills fluttered at the junction of thorax and abdomen.
“It’s a mayfly,” she said.
It was a good day for mayflies, a creature classified as pollution-sensitive, as the Vasses counted nearly two-dozen of them. But other types of macroinvertebrates were scarce.
Whitney Vass piped a measure of stream water into a test tube and mixed in eight drops of bromothymol blue, a pH indicator. She measured it against a continuum of greenish hues that correspond to relative acidity. Runoff from yards and discharge from wastewater plants can affect the neutrality of stream water, making it less livable for the macroinvertebrates that call Brush Creek home.
Courtenay Vass picked up a biology degree from Radford College in Virginia before starting the family that now resides in Greensboro. She has also recently been attending the workshops necessary for her environmental education certification. In her family’s case, the apples don’t fall far from the tree. Whitney Vass, a freshman at Page High School, has aspirations of becoming a marine biologist and her sister Austin wants to do “whatever job involves scuba diving.”
They’ve used the data and skills collected during the past six years in school science fair projects, including one where Whitney Vass plotted their macroinvertebrate finds according to water temperature. She discovered that they had found fewer animals during the cold weather.
“Maybe they’re hibernating or something,” Whitney Vass said.
“Or maybe because it’s cold outside we’re not looking as hard,” her mother said, delivering a gentle lesson in statistical fallacy.
The water quality at Brush Creek rated fair. But the Vass sisters noticed a disturbing change as they scouted the landscape.
“Mom, there’s a lot of algae over here,” Whitney Vass said.
“It looks like tomato soup,” Austin Vass said.
“No, it looks like cheese,” Whitney Vass said. “There’s cheddar over here and feta down there.”
They pointed at a stagnant arm on the near side of a wide island. Underneath the water, clouds of red-orange algae bloomed. Such algal blooms can be the result of fertilizer runoff and can monopolize dissolved oxygen to the detriment of other underwater dwellers.
“Mom, there’s gotta be something wrong because they shouldn’t have algae on them,” said Austin Vass as she examined an algae-covered damselfly.
Her sister marked the creature down and noted the algae. Then the Vass family gathered their supplies and the data that they, along with dozens of other river watchers in the state, will send to the Haw River Assembly. They changed back into their sneakers and bid a temporary adieu to the thriving algae and mayflies of Brush Creek.
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