On a recent Sunday morning, 93-year-old Bernie Fowler laced up his white sneakers and waded into Maryland’s Patuxent River, a tributary of the Chesapeake Bay, just as he has done every June for the past 30 years. He was conducting his annual test of water clarity by seeing how deep he could go and still see the tops of his shoes.
“It was the third best reading we’ve had in 30 years,” said the six-foot tall Fowler, adding that he recorded a depth of 41 ½ inches—not quite as high as the 44 inches he measured in the early 1990s, but considerably better than those at the start of his wade-ins, which began in 1988.
“When we first started, the first reading was something like 8 to 10 inches,” he recalled. “You put your foot in, and that was it. You couldn’t see your foot.”
Water clarity is important to the health of ecosystems, since sunlight must reach below the surface to help underwater plants grow. Sewage, erosion and microscopic algae known as phytoplankton are turning waters murky all over the globe.
NASA, which uses satellites to assess water quality, has endorsed Fowler’s method, calling it “Fowler’s Sneaker Depth.” Fowler isn’t a trained researcher. He’s what experts call a “citizen scientist.” He’s made it his mission to track the health of the Patuxent River.
NASA researchers created an algorithm based on Fowler’s sneaker calculations as part of a study published in the journal Optics Express. The paper points out that Fowler’s concept is similar to a tool already in use called the Secchi disk. Researchers lower a plain, white disk on a rope into the water and record the depth at which it disappears from sight.
Fowler grew up on the Patuxent River in Maryland. His father and brothers were watermen who harvested crabs, fish, oysters and now-extinct soft-shelled clams. “I spent a lot of time on the river,” he said.
When Fowler returned after serving in World War II, he opened a boat rental business on the river, spending time during the week crabbing and fishing for the sandwiches he sold in his shop and for family meals. “We didn’t buy anything,” he added. “It went right from the river to the table.”
When he was a young man, Fowler could wade in and not be able to keep his feet on the bottom, he remembers. He could go far enough for his body to become buoyant, the water so clear that “I could still see the crabs at the bottom,” he says.
Starting in the early 1970s, when he became Calvert County commissioner — and later when he served in the state senate — Fowler participated in several lawsuits that forced the state and the Environmental Protection Agency (EPA) to enact pollution control measures. During the Obama administration, the EPA imposed new cleanup standards on large wastewater treatment plants along the Patuxent River. Nevertheless, the river and the bay still suffer from pollution, the result of a growing population. “Everybody wants to live in the bay area,” Fowler said.
For the study, Ben Crooke, a 17-year-old summer intern at NASA and the paper’s lead author, spent part of his summer comparing Fowler’s data with satellite imagery. He and his colleagues examined data from an instrument onboard the satellite which measures the different colors of light reflected by matter suspended in the water.
They specifically looked at the amount of red light reflected by floating sediments that make the water appear cloudy and then developed a mathematical model to relate the amount of red light reflected with the sneaker depth, as measured by Fowler.
The NASA team hopes to refine the algorithm, possibly setting the maximum limit of sneaker depth at Fowler’s height — six feet — as a way to honor him. And they welcome more community input. “If you have a pair of old white sneakers and put them on your feet, or a string, and take some measurements, that could help us build a data set and fine tune the algorithm,” said Lachlan McKinna, an oceanographer at NASA’s Goddard Space Flight Center and coauthor of the study.
The NASA team also found that river quality varies with the season. Winter months had the best visibility because river flow is minimal, which means less sediment and less phytoplankton growth. In the late spring and early summer, waters are at murkiest thanks to the abundance of algae and sediments. Pollution also plays a factor in visibility.
“Things have improved. The crabs and the fish and the oysters have improved,” Fowler said. “There are good signals, but it doesn’t mean we need to decrease our efforts. It will take a long time to clean that bay up.”
After the most recent wade-in, Fowler did what he does every year. He took his sneakers outside, rinsed them off with his garden hose, and let them dry in the sun. Then he put them in a corner of his clothes closet for next year.
His first pair of sneakers held up for 20 years before falling apart. His second pair lasted eight years. He bought his current pair two years ago and said, “I can get another five years out of them.” He’s trying to persuade his 56-year-old son to take over the wade-in if and when the time comes, “but he’s not yet told me yes or no,” Fowler said.
For his part, however, Fowler intends to keep on wading every June, “as long as the Lord will let me do it.”
Marlene Cimons writes for Nexus Media, a syndicated newswire covering climate, energy, policy, art and culture.