As the story goes, the first person to spot a trout rising in Paint Branch in the 1970s — a Maryland stream that already passed under a half-dozen highway ramps on its way to the Anacostia River — could hardly believe it. And despite increased development in the surrounding landscape since then, the trout have continued to persevere and reproduce in a Paint Branch tributary called Good Hope.
But they may soon be little more than urban legend.
For 40 years and counting, Maryland’s Department of Natural Resources has documented the little-known presence of wild brown trout in the relatively cool waters of the Good Hope. For half of those decades, every November, biologists could walk to a particular spot along the stream and see spawning beds, where trout had fertilized and covered eggs for protection through the winter. And every spring and summer, for just as long, biologists could find the fish returning to feed and shelter beneath tree roots hugging the shore.
“You could set your watch by it,” said Mark Staley, a DNR biologist who’s been participating in the annual counts since the late ’80s. “It’s remarkable that this stream was here and that it maintained the quality that it had for so very long.”
When the counts began in 1979, electrofishing surfaced nearly 40 brown trout in the Good Hope, a tributary to Paint Branch that serves as the trout’s central spawning grounds. There were trout of various sizes and newly hatched juveniles. Those numbers peaked at just more than 50 in the mid-1990s, but have been declining steadily since 1999.
Last year, officials counted just five adult trout in the Good Hope, all around the same age, which indicates that recent spawns have not been successful. When they look again later this summer, Staley hopes they’ll find at least one.
“I’m sure they’re still attempting to spawn, but either the substrate’s not conducive or the winter floods mess up the nests, or other factors don’t allow the reproduction that’s taking place to be successful,” Staley said. “There’s no smoking gun. There are multiple tipping points.”
Brown trout are not native to the United States but were introduced from Europe as a popular sporting fish. Officials think they came to Paint Branch waters in the 1930s.
“Brownies,” as well as the more sensitive native brook trout, are good indicators of stream health because they need cool, clean water to reproduce. They disappear when those conditions aren’t met.
Less than 10% of Maryland streams can host trout, which cannot typically withstand water temperatures above 68 degrees. That leaves trout relegated mostly to rural headwaters, away from developed land that warms the water and buries spawning grounds in sediment.
The landscape around Paint Branch has become increasingly urbanized during the brown trout’s 80-year presence there. Yet, somehow, the trout have survived, even as they have shrunk back to their spawning grounds in the Good Hope. Staley said abundant and cool groundwater fuels trout-worthy temperatures, and shade helps keep them cool.
The trout population and requisite water quality are a rarity in the area, and advocates have rallied to protect the watershed from development.
“I spent a good portion of my life fighting for this,” said David Dunmire, a member of the Eyes of Paint Branch. “And they’re still there.”
Dunmire, who lives in the Good Hope’s watershed in Silver Spring, MD, said the tributary and Paint Branch have been “hallowed ground” for as long as he can remember, and not just because of the trout. The conditions that have allowed the trout to survive — perfectly sized pebbles in a shaded, meandering streambed — are unique in the otherwise crowded suburbs of the District of Columbia.
Dunmire said the Eyes of Paint Branch went from six to 60 members almost overnight in the mid-1990s, when officials first floated ideas for a new six-lane freeway across the watershed. Their attempt to stop the project ultimately failed, and the Intercounty Connector now crosses Paint Branch three times.
Still, the group’s work set a series of initiatives into motion that would — at least on paper — limit new development in the watershed, transfer a chunk of the headwaters into county parklands and create an environmental “special protection area” for the high-quality stream, the first of its kind in Montgomery County.
On a morning in early June, verdant ferns unfurled along each side of the Good Hope and an unnamed tributary that feeds it, lit by sunlight filtered through a diverse forest canopy. Nearby homes were invisible from the stream, which benefits from thick foliage and a 1,000-acre stream valley park, set aside years ago with the help of advocates like Dunmire.
Greg Smith, who led an effort to oppose the Intercounty Connector, said the project’s eventual approval was so devastating that it took him years to visit the area again. He still thinks of it as “one of the most destructive projects” in the Atlantic region at the time. He was surprised to hear of the trout surviving as long as they have.
“It’s unlikely that throwing 10 lanes of pavement across the heart of a forested stream valley did the trout a lot of good,” he said, adding the freeway’s shoulders to the lane count.
Staley, who continued monitoring the trout population during and after the freeway’s construction, said costly and innovative techniques to control sediment and erosion went far to minimize impacts to the stream, but it might have been too late. By the time it was built, the acreage of impervious surface in the county already had risen from less than 8% to more than 10%. The trout population had already begun its decline.
Other factors contributed, too. In 2003, Hurricane Isabel washed a fresh layer of sediment into the system, covering some of the substrate that had been suitable for spawning. More frequent and heavier rains, especially in the winter months, also are thought to have gradually covered thumb-sized pebbles, which an 8-inch trout might move to cover a nest, with larger cobble.
“It’s been death by a thousand cuts,” Staley said as he stood near a bend in the Good Hope where he would almost always find trout in years past.
To the naked eye, the clear water, cool to the touch, still looks ideal, particularly for waters so near a neighborhood.
“This is not a bad stream,” he added. “It’s in good shape compared to many urban streams. It’s just not good enough for trout any longer.”
Mark Taylor, a spokesman for Trout Unlimited, said his organization sees similar combinations of habitat changes leading to the end of trout runs in other suburban areas. He’s witnessed it near his home in Roanoke, VA, where brown trout eventually disappeared from a spring-fed stream running through the city. He said increases in extreme weather, especially heavy rains or flooding in the winter months, can be the last straw for streams that have become less resilient to such changes.
Winter flooding “happens in nature, too. But when it happens three years in a row, then you’ve created a system that can sometimes push the trout past the point of no return,” Taylor said.
But, for the trout in the Good Hope, Dunmire and others still have a little optimism left. As long as they are there, even a few of them, “nature has not upended,” he said.
“The jury is still out,” Dunmire added. “We still have a lot of natural diversity here. We’re hoping the trout can hang on, too.”