What fish live in the Schuylkill and which are safe to eat?

Kevin Rodenbaugh fished until 3 a.m. one day this week, went home, caught a few hours of sleep, and was back scrambling down rocks along the Schuylkill in Bridgeport at 9 a.m.

The wiry 20-year-old whipped his medium-heavy rod with practiced ease. A plastic worm slashed through the air at the end of his braided line in search of live prey: smallmouth bass living near where water rushed over falls at the Norristown Dam. Rodenbaugh fishes up to six days a week for muskie, catfish and bass. "It's like a little vacation," he said.

Are fish thriving in the Schuylkill? And what's the overall health of the river? Those questions were raised through Curious Philly, our new question-and-response forum that allows readers to submit questions about their community in need of further examination.

We set out to find answers.

Rodenbaugh made a splash a few weeks ago when he caught a 45-inch muskie near the same spot on the Schuylkill that serves as the border between Bridgeport and Norristown, his hometown.

"After I posted the picture of the muskie, people said, 'I never knew there were fish in there, or I thought they were all three-eyed.' "

In fact, the 135-mile-long Schuylkill is an increasingly healthy river system, according to scientists, officials, and environmental groups. Up to 54 species of fish have been identified over time as having been present, in varying amounts, in the portion of the lower Schuylkill that runs through Philadelphia.

"Within the last 20 years, and especially within the last 10 years, the Schuylkill has gotten much cleaner," said Lance Butler, a scientist and watershed manager for the Philadelphia Water Department.

Butler explained that the Schuylkill was once so polluted in Philadelphia that it had a dead zone, meaning the oxygen in the water was so low it made it hard for aquatic life to thrive. Man-made chemicals, like PCBs, and other toxics contaminated the river from industrial waste.

The federal Clean Water Act of the 1970s created new water-quality standards. Governments were forced to upgrade their wastewater treatment plants. Industry began to clean up discharges. As a result, bacteria levels dropped and oxygen levels increased. Those improvements were important not only for fish but for people. The Delaware River and the Schuylkill provide 230 million gallons of drinking water daily for the city through three plants that process untreated river water. Two of the plants are on the Schuylkill, one at Queen Lane and one on Kelly Drive, and produce water that is cleaner than recommended federal standards.

Another way to help keep the river clean: mussels, which filter pollutants, functioning as mini wastewater treatment plants. One mussel can filter 10 to 20 gallons of water a day.

Butler is part of a team at the freshwater mussel hatchery at Fairmount Water Works. Its goal is to repopulate the Schuylkill with native species of mussels, which would keep the river cleaner for fish while also providing food for them. The hatchery is on track to release 15,000 to 20,000 mussels from five different species this year. Eventually, a hatchery at Bartram's Garden is expected to raise up to 500,000 mussels a year for the river.

Rich Horwitz, a scientist and fisheries section leader at the Academy of Natural Sciences of Drexel University, also credits the installation of fish ladders along the river with increasing the number of fish, such as shad. A fish ladder provides a sort of detour migrating fish can take around a dam or obstruction. The ladder contains a series of ascending pools that allow the fish to move through.

For example, the fish ladder installed in 2008 at the Fairmount Dam allows fish to move upstream. And a few dams have been removed or breached along the Schuylkill in Philadelphia and above, also making it easier for fish to move.

Horwitz said bluegill sunfish, redbreast sunfish, minnows, shiners, and white suckers are all present in the river. He said a recent sampling found American eels, carp, pumpkin seed sunfish, largemouth bass, flathead catfish, and channel catfish.

But PCBs, left over from the city's more industrial past, remain a concern since they are still present at the river's bottom, Horwitz said.

In general, data show contaminants in fish are declining and some fish are edible. But that doesn't mean experts advise eating a lot of fish caught in the river. The state Fish and Boat Commission issues consumption advisories on fish commonly caught along the river such as eel, carp, and catfish. Most suggest just one meal of a species a month, or caution against eating the fish altogether.

For example, you can eat catfish, white perch, and striped bass caught in the river near Philadelphia once a month. But American eel and carp are too contaminated by PCBs because they are bottom feeders. Farther up the river, away from the city, in Berks, Chester, and Montgomery Counties, where contamination is less, it's safe to eat up to six meals per year of carp and catfish.

Mike Kaufmann, the Southeastern Pennsylvania fisheries manager for the commission, said that the disappearance of smokestack industries along the river has helped. He also attributes a lot of the improvement to Philadelphia's push to get stormwater and wastewater, which carry pollutants, under control. During a storm, water can overwhelm treatment plants and rush into the river. The city Water Department also has a program to track down "cross-connections" — mixed-up pipes from homes that can reroute sewage into the river.

Danielle Kreeger, science director for the nonprofit Partnership for the Delaware Estuary, called improvement to the river's water quality "tremendous." Her organization puts out a detailed technical report every five years that includes data on all the waterways, including the Schuylkill, that flow into the Delaware and, ultimately, the estuary.

The report identifies several continued threats, such as development. The population along the watershed above Philadelphia has grown by 6 percent since 2000. Much of that growth has been in Chester and Montgomery Counties, where waterways such as the Pickering, Perkiomen, and Wissahickon all flow into the Schuylkill. More people mean more parking lots, roadways, lawn fertilizer use, and wastewater.

As part of her job, Kreeger snorkels and dives in the Schuylkill.

"In the tidal part of the river [below Fairmount Dam] we see everything," Kreeger said. "It can get pretty disgusting. And you have to wade through rafts of plastic water bottles. It's so disheartening. There's so much trash."

She said scientists also now watch for contaminants such as dissolved nutrients that fuel algae. They are looking at personal care products, antibiotics, and pharmaceuticals — "the things we flush down the toilets." Pharmaceuticals, for example, have been shown to impact the endocrine systems of fish, creating intersex fish with male and female characteristics.

But, overall, she notes, the Schuylkill, especially above the dam, has made real progress. Her organization's report shows that the level of dissolved oxygen in the Schuylkill — a key indicator — is above 5 milligrams per liter, a healthy level.

"There's the perception of the Lower Schuylkill that it's a working polluted river, but that's not the case," Kreeger said.