Pittsburgh — On a mild November afternoon, Duquesne University biological sciences professor Brady Porter leads students on a field trip to Nine Mile Run, an urban tributary of the Monongahela River.
Porter uses electrofishing gear to bring fish to the surface for his students to net and then process on site, logging species diversity and population densities.
The project serves both to educate budding fisheries biologists and to measure the recovery of what had once been a stream so impaired it was referred to by locals as S…t Creek.
The transformation began in 2006, when a slew of partners, ranging from the U.S. Army Corps of Engineers to a fledgling watershed group now known as UpstreamPgh, undertook one of the most ambitious urban stream restorations anywhere in the United States.
Porter has been among those chronicling the progress of the $7.7-million project, which included reconfiguring the stream, adding step pools, planting the floodplain with native vegetation, and installing rain gardens and other green solutions to rein in runoff in watershed communities.
Although the work is ongoing, it is paying off.
“In the early years of the project there was a major jump from nothing to what we’d rank as poor, and that has slowly risen to what we’d now call fair and heading toward good,” Porter said.
“The stream has had its ups and downs over the years but the trend is toward overall good recovery.”
As proof, this year’s surveys indicate the presence of 19 species – most of them forage fish – in the lower reaches near where Nine Mile meets the Mon.
About 1,735 fish were counted in September until rising water from Hurricane Ian cut the survey short.
Follow-up sampling weeks later yielded 678 fish, Porter said. “Ian didn’t impact diversity richness, but it influenced abundance.”
Further upstream, beyond several sewer lines and other impediments to fish movement, diversity drops to what Porter calls “the dirty handful,” or pollution-hardy species that include green sunfish, white suckers, creek chubs, black-nose dace and blunt-nosed minnows.
That their populations are dense is an encouraging sign, he said.
“They’re the core of ‘most-tolerant’ fish but they couldn’t live in Nine Mile at all before the restoration. The fact that they are there in huge numbers is pretty impressive.”
What’s notable about chubs, aside from their desirability as a bait fish, is that they are stream pioneers, Porter said. “They’re the first to arrive in a stream section once it gets watered.”
In recent years, he occasionally has found smallmouth bass near the mouth of the run, as well as an improving diversity of darters.
“Darters are percidae – they’re like miniature walleyes – and good water-quality indicators,” Porter said. “They’re also beautiful. The females are drab but the males are beautifully colored in red, blue, purple and green.”
Five different kinds of darters have been collected, although they are represented by just one to three individuals, Porter said. “But the fact that they are here at all shows great improvement in water quality.”
Duquesne University graduate student Meredith Bennett has
helped sample for years and said “something pleasantly surprising”
seems to turn up every time, including, this fall, when students
discovered a young snapping turtle at the mouth of the run, near a neigh
borhood called Duck Hollow.
While she called the progress made so far “amazing … considering the stream
was basically used as a dump for decades,” she notes that, during
overflow events, sewage can be seen and smelled, “so there is a lot of
work to be done.”
Because it is a Saturday, the park has plenty of visitors, some of whom are
curious about what Porter and his students are doing. They stop to ask
questions as fish are scooped from buckets and catalogued.
Senior biology major Jordan Zottola enjoys the opportunity to educate the
public. “It enables people to see how important conservation work is,”
Perhaps no one has a better perspective on the restoration of the run than Michael
Koryak, the U.S. Army Corps of Engineers limnologist who was with the
project from the beginning.
He also lived for years within walking distance of the stream. Although he
is now retired, Koryak has sampled fish and water every year since
2006, and accompanies Brady on his annual field trip as a volunteer.
Before the work began, there were no fish in the upper reaches and just four
species, and 19 fish total, in the lower section, he said. “So you can
see how far it has come.”